MXPA00009102A - Open-cell foam and method of making - Google Patents

Abstract

An open-cell polystyrene foam is provided which is formed from a blend of polystyrene and an ethylene-styrene interpolymer. The ethylene-styrene interpolymer functions as a cell opening agent, and is used to control the open cell content of the resulting foam, which may contain greater than 80 percent open cells. The foam is produced by an extrusion process in which carbon dioxide is used as the preferred blowing agent. The resulting foams may be formed into beads, plank, round, sheets, etc.

Description

OPEN CELL FOAM AND PREPARATION METHOD The present invention relates to an open cell foam, and more particularly, to an open cell foam having a controllable level of open cells, and a method for making such foam. The subject has recognized that the use of mixtures of two thermoplastic resins in the formation of foams can allow one to obtain advantageous properties of each resin in the resulting foam. For example, the foams formed of polystyrene are light in weight and show stiffness and good shape conservation, while the foams formed of polyolefins have flexibility and good properties of impact absorbency. However, the union of polystyrene and polyolefin resins has been complicated by the incompatibility of the two resins. Attempts have been made to solve this problem of incompatibility with the use of compatibilizers such as block copolymers or grafts that improve adhesion between the two polymer interfaces. However, it has been found that even with the use of a compatibilizer, most polymer blends of polyolefins and polystyrenes are difficult to form in good quality open cell foams by a conventional extrusion process. Most mixed polymer foams formed by extrusion processes result in foams showing deficient layers, uneven cell distribution, partial collapse or weak mechanical strength. This is mainly due to the fact that during the extrusion process, the control of the foaming temperature plays a critical role in the formation of a good quality foam, and the melting temperature range, or "window7 is extremely narrow for The formation of open cell foams Thus, it would be desirable to be able to provide a wider foaming temperature range to ensure the formation of a good quality foam, attempts have been made to overcome some of these problems. , Park in U.S. Patent No. 4,605,682 describes the production of open-cell foams by an extrusion process, of a mixture of polystyrene and polyethylene resins, by slightly degrading the resins with a peroxide. peroxide makes the process more complex since the peroxide is highly reactive.In addition, the resulting foam has a low open cell content and is relatively soft, since polyethylene constitutes the main phase of the mixture. It would be advantageous to be able to make a foam in which polystyrene is the main phase, so that the resulting foam would have a higher compressive strength, making the foam more suitable for construction applications. It would also be desirable to control the level of open cells to achieve the desired foam properties. The U.S. Patent No. 5,41 1, 687 (D. Imeokparia et al) describes an extruded open-cell alkenyl aromatic polymer foam, in which a nucleating agent is used in combination with a foaming temperature of from 3 to 15 °. C higher than the highest foaming temperature for a corresponding closed cell foam, resulting in an extruded open cell foam having an open cell content of 30 to 80 percent. The U.S. Patent No. 5,674,916 (C. Scmidt et al), discloses a process for preparing an extruded open cell microcellular alkenyl aromatic polymer foam, in which a nucleating agent in combination with a blowing agent having a nucleation potential is used. relatively high intrinsic in an amount small enough to allow the formation of an open cell structure and a relatively high foaming temperature. This results in an extruded open cell foam having an open cell content of about 70 percent or more and microcellular cell size of 70 microns or less. WO 9858991 discloses a method for increasing open cell formation using an alkenyl aromatic polymer blend and up to seven percent of an entilene copolymer having a Vicat softening point less than or equal to 85 ° C (such as ethyl vinyl acetate)., EVA). However, the use of incompatible polymeric materials such as LLDPE and EVA as an opening agent of the cell at the foaming temperatures used to generate open cells in the foam body, results in deterioration in the surface quality of the foam. the foam. Thus, there is a need in the art for a good quality open cell polymer blend foam and a foam making process that provides a wider foaming temperature window, improved surface quality and a controllable level of the open cells. The present invention satisfies that need by providing an open cell foam prepared from a mixture of an alkyl aromatic polymer and a substantially random interpolymer and an extrusion process for its preparation, wherein said foam has a controllable level of open cells and said The process for making the foam provides a wider foaming temperature window, which results in a foam having improved surface quality and a controllable level of open cells. Definitions All references herein to the elements or metals belonging to a certain Group refer to the Periodic Table of the Elements published and protected by copyright by CRC Press, Inc., 1989. Also any reference to the Group or Groups must make the Group or Groups as reflected in this Periodic Table of the Elements using the IUPAC system to number the groups.

Any numerical value quoted herein includes all values of the value less than the upper value in increments of one unit as long as there is a separation of at least 2 units between any lower value and any higher value. As an example, it is stated that the amount of a component or a value of a process variable such as, for example, temperature, pressure, time is, for example, from 1 to 90, preferably from 20 to 80, more preferably from 30 to 70, it is proposed that values such as 15 to 85, 22 to 68, 43 to 51, 30 to 32, etc., are expressly listed in this specification. For values that are less than one, a unit is considered 0.0001, 0.001, 0.01 or 0.1 as appropriate. These are only examples of what is specifically proposed and all possible combinations of numerical values between the lowest value and the highest value listed are considered to be expressly set forth in this application in a similar manner. The term "hydrocarbyl" as used herein means any aliphatic, cycloaliphatic, aromatic, substituted aryl aliphatic, substituted aryl cycloaliphatic, aliphatic substituted aromatic, or aliphatic substituted cycloaliphatic group. The term "hydrocarbyloxy" means a hydrocarbyl group having an oxygen bond between it and the carbon atom to which it is attached. The term "interpolymer" is used herein to mean a polymer wherein at least two different monomers are polymerized to make the interpolymer. This includes copolymers, terpolymers, etc. The term "open cell foam" is used herein to mean a foam having at least 20 percent open cells as measured according to ASTM D 2856-A. The term "optimum foaming temperature" is used herein to indicate a foaming temperature at or above the glass transition temperature of the blends or melting point and within a range, in which the foam does not collapse. The invention especially covers foams comprising mixtures of one or more alkenyl aromatic homopolymers, or copolymers of alkenyl aromatic monomers, or copolymers of aromatic alkenyl monomers with one or more ethylenically copolymerizable comonomers (other than ethylene or C3-C12 α-olefins) linear), or combination thereof with at least one substantially random interpolymer. The alkenyl aromatic polymer material can be comprised only of one or more alkenyl aromatic homopolymers, one or more alkenyl aromatic copolymers, a mixture of one or more of each of the copolymer and alkenyl aromatic homopolymers, or mixtures of any of the above with an aromatic non-alkenyl polymer. The alkenyl aromatic polymer material may further include minor proportions of non-alkenyl aromatic polymers. Regardless of the composition, the alkenyl aromatic polymer material comprises more than 50 and preferably more than 70 weight percent aromatic monomeric alkenyl units. More preferably, the alkenyl aromatic polymer material is entirely comprised of alkenyl aromatic monomer units. Suitable alkenyl aromatic polymers include homopolymers and copolymers derived from alkenyl aromatic compounds, such as styrene, alphamethylstyrene, ethylstyrene, vinylbenzene, vinyl toluene, clobutyrene, and bromostyrene. A preferred alkenyl aromatic polymer is polystyrene. Minor amounts of monoethylenically unsaturated compounds such as esters and C 2-6 alkyl acids, ionomeric derivatives, and C 4-6 dienes can be copolymerized with alkenyl aromatics. Examples of copolymerizable compounds include acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, itaconic acid, acrylonitrile, maleic anhydride, methyl acrylate, ethyl acrylate, isobutyl acrylate, n-butyl acrylate, methyl methacrylate, vinyl acetate and butadiene. The term "substantially random" (in the substantially random interpolymer comprising polymer units derived from ethylene and one or more monomers of a-olefins with one or more vinylidene aromatic monomers or vinyl or vinylidene monomers or vinyl, aliphatic or cycloaliphatic, or combinations thereof) as used herein means that the monomer distribution of said interpolymer can be described by the Bernoulli statistical model or by a first or second order Markovian statistical model, as described by JC. Randall in POLIMER SEQÚENSE DETERMINATION, Coal -13 NMR Meted, Academic Press New York, 1 977, pp. 71 -78. Preferably, the substantially random interpolymers do not contain more than 15 percent of the total amount of vinyl aromatic monomer in aromatic vinyl monomer blocks of more than 3 units. More preferably, the interpolymer is not characterized by a high degree of either isotacticity or syndiotacticity. This means that in the carbon spectrum "13 NMR of substantially random interpolymer the peak areas corresponding to the methylene backbone and carbon methine representing either sequences meso bivalent radical or sequences racemic bivalent radical should not exceed 75 percent of the total peak area of the methylene main chain and methine carbons According to the above, it is a feature of the present invention to provide an open cell foam having a controllable level of open cells. The invention provides a method for making such open cell foam The additional applications for open cell foams of the present invention include vacuum isolation, filtration and fluid absorption applications, and other features and advantages of the present invention. will be apparent from the following description of carved and the appended claims. The addition of a substantially random interpolymer, preferably an ethylene-styrene substantially random, to foams alkenyl aromatic polymer, preferably polystyrene foams results unexpectedly a foam having openings controllable cell without adversely affecting the foam quality. While not wishing to join a particular theory, it is believed that the interpolymer is random substantially compatible with, but not miscible with the alkenyl aromatic polymer, it acts as a starter cell to form a multitude of domains in the phase aromatic polymer of alkenyl of the mixture. The droplets of the substantially random interpolymer, which have a low solidification temperature, remain fluid even near the end of the expansion of the foam, thus providing the starting points of the cell opening. In the preferred embodiment of the present invention of an open-cell alkenyl aromatic polymer foam, we have found that the amount of open cell content increases as the level of substantially random ethylene-styrene interpolymer increases, thereby allowing a Open cell level is controlled by the desired application. For a foam nterpolímero ethylene-styrene substantially random we have found that the amount of content open cell increases as the level of alkenyl aromatic polymer is increased, thus allowing the level of open cells is controlled by the desired application. For example, a partially open cell foam (eg 20-50 percent open cells) is particularly suitable for applications that require greater foam dimensional stability and faster maturation, while fully open cell foam (eg 80 percent or more open cells) can be used in a filtration, fluid absorption and sound absorption applications. We have also found that the addition of the substantially random interpolymer allows a wider foaming temperature window. In the past production of open-cell foams, it has been necessary to increase the foaming temperature by 5 to 10 ° C above the temperatures normally used to produce closed-cell foams in order to promote the opening of the cell. However, such an increase in temperature often degrades the quality of the foam since excessively high foaming temperatures can cause the foam to collapse due to the rapid loss of blowing agent and reduced ability of the cell struts to resist. the ambient pressure. In addition, high temperatures can reduce pressures of the extrusion die to unacceptably low levels and negatively impact the quality of the layer, resulting in a very narrow foaming temperature window within which good quality foams can be produced. By using substantially random interpolymers and preferably substantially random ethylene-styrene interpolymers, the foams of the present invention can be processed using the same temperature conditions as those used in the past for the production of a closed cell foam, resulting in a wider foaming temperature window. The preferred foaming temperatures will vary from 1 ° C to 135 ° C, where the foaming temperature is from 3 ° C to 15 ° C less than the highest foaming temperature. It should be appreciated that the desirable foaming temperatures will vary depending on the factors including the characteristics of the polymer material, the concentration and composition of the blowing agent and the configuration of the extrusion system. We have also found that the addition of the substantially random ethylene-styrene interpolymer can be adapted to produce high open cell content, small cell size foams for applications requiring this combination, or high open cell content, large cell size foams for applications that require this combination. The interpolymers used to prepare the foams of the present invention include the substantially random interpolymers prepared by polymerizing i) ethylene or one or more α-olefin monomers, or combinations thereof and ii) one or more vinylidene or vinyl aromatic monomers or one or more sterically hindered cycloaliphatic or aliphatic vinylidene or vinylidene monomers, or combinations thereof, and optionally iii) other polymerizable unsaturated ethylenically (s) monomer (s). Suitable α-olefins include, for example, α-olefins containing 3 to 20, preferably 3 to 12, more preferably 3 to 8 carbon atoms. Particularly suitable are ethylene, propylene, butene-1,4-methyl-1-pentene, hexene-1 or octene-1. These α-olefins do not contain an aromatic part. Other ethylenically unsaturated monomer (s) polymerizable (s) include norbornene and substituted aryl norborne C6-? Oo alkyl C1"10, with an exemplary interpolymer being ethylene / styrene / norbornene.The aromatic vinylidene monomers or suitable vinyl which can be used to prepare the interpolymers include, for example, those represented by the following formula: Ar I (CH2) n Ri - c = C (R) 2 wherein Ri is selected from the group of radicals consisting of alkyl and hydrogen radicals containing from 1 to 4 carbon atoms, preferably hydrogen or methyl; each R is independently selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms, preferably hydrogen or methyl; Ar is a phenyl group or a phenyl group substituted with from 1 to 5 substituents selected from the group consisting of halo, C 1-4 alkyl, and C? - haloalkyl; and n has a value from zero to 4, preferably from zero to 2, more preferably zero. Exemplary vinyl aromatic monomers include styrene, vinyl toluene, α-methylstyrene, t-butyl styrene, chlorostyrene, including all isomers of these compounds. Particularly suitable such monomers include styrene and substituted derivatives of halogen or lower alkyl thereof. Preferred monomers include styrene, α-methyl styrene, lower alkyl- (C 1 -C 4) or substituted ring derivatives of styrene phenyl, such as, for example, ortho-, meta- and para-methylstyrene, the halogenated ring styrenes, para-vinyl toluene or mixtures thereof. By the term "vinylidene vinylidene or sterically hindered aliphatic vinylidene compounds" means the addition of polymerizable vinylidene or vinyl monomers corresponding to the formula: A 'RI - - C = CiR2), wherein A1 is a cycloaliphatic or aliphatic substituent sterically bulky up to 20 carbons, R1 is selected from the group of radicals consisting of alkyl and hydrogen radicals containing from 1 to 4 carbon atoms, preferably hydrogen or methyl; each R2 is independently selected from the group of radicals consisting of alkyl and hydrogen radicals containing from 1 to 4 carbon atoms, preferably hydrogen or methyl; or alternatively R1 and A1 together form an annular system. The vinylidene or cycloaliphatic or aliphatic vinyl compounds are monomers in which one of the carbon atoms bearing non-ethylenic saturation is tertiary or substituted quaternary. Examples of such substituents include cyclic aliphatic groups such as cyclohexyl, cyclohexenyl, cycloocteninol or aryl derivatives or ring alkyl thereof, tert-butyl and norbonyl. The most preferred cycloaliphatic or aliphatic vinylidene or vinyl compounds are the various ring-substituted isomeric vinyl derivatives of substituted cyclohexanes and cyclohexanes, and 5-ethylidene-2-norbonene. Especially suitable are 1 -, 3- and 4-vinylcyclohexane. Simple straight, unbranched α-olefins including, for example, α-olefins containing from 3 to 20 carbon atoms such as propylene, butene-1,4-methyl-1-pentene, hexene-1 or octene-1 do not are examples of sterically hindered cycloaliphatic or aliphatic vinylidene or vinyl compounds. One method of preparing sub-stantially random interpolymers includes polymerizing a mixture of polymerizable monomers in the presence of one or more forced geometry or metallocene catalysts in combination with several cocatalysts, as described in EP-A-0,416,815 by James C. Stevens et al. to the. and U.S. Patent No. 5,703, 187 by Francis J. Timmers. The preferred operating conditions of such polymerization reactions are atmospheric reactions up to 3000 atmospheres and temperatures from -30 ° C to 200 ° C. Polymerizations and removal of unreacted monomer at temperatures above the autopolymerization temperature of the respective monomers may result in the formation of some amounts of homopolymer polymerization products resulting from free radical polymerization. Examples of suitable catalysts and methods for preparing substantially random interpolymers are described in EP-A-514,828, as well as US Patents. 5,055,438; 5,057,475; 5,096,867; 5,064,802; 5, 132,380; 5, 189, 192; 5,321, 106; 5,347,024; 5,350,723; 5,374,969, 5,399,635; 5,470,993; 5,703, 187 and 5,721, 185. Substantially randomized α-olefin / vinyl aromatic interpolymers can also be prepared by the methods described in JP 07/278230 which employ the compounds shown by the general formula 3 \ / \ / \ CF ~ R ~ wherein Cp1 and Cp2 are cyclopentadenyl groups, indenyl groups, fluorenyl groups or substituents thereof, independently of one another; R1 and R2 are hydrogen atoms, halogen atoms, hydrocarbon groups with carbon numbers of 1 -12, alkoxy groups, or aryloxy groups, independently of one another; M is a group IV metal, preferably Zr or Hf, more preferably Zr; and R3 is an alkylene group or silanedyl group to degrade Cp1 and Cp2. The substantially random α-olefin / vinyl aromatic interpolymers can also be prepared by the methods described by John G, Bradfute et al (W.R. Grace &Co.) in WO 95/32095; by R.B. Panell (Exxon Chemical Patents, Inc.) in WO 94/00500; and in Plastics Technology, p. 25 (September 1992). Also suitable are substantially random interpolymers comprising at least one a-olefin / vinyl aromatic / vinyl aromatic / α-olefin tetrad described in WO 98/09999 by Francis J, Timmers et al. These interpolymers contain additional signals in their carbon 13 NMR spectrum with intensities greater than three times peak to peak noise. These signals appear in the range of chemical change 43.70 - 44.25 ppm and 38.0 - 38.5 ppm. Specifically, the largest peaks are observed at 44.1, 43.9 and 38.2 ppm. An NMR experiment of proton test indicates that the signals in the region of chemical change 43.70-44.25 ppm are methine carbons and the signals in the region 38.0-38.5 ppm are methylene carbons. It is believed that these new signals are due to sequences that include two vinyl aromatic monomer insertions from top to back preceded and followed by at least one α-olefin insert, for example ethylene / styrene / styrene / ethylene tetrad. wherein the styrene monomer insertions of said tetrads occur exclusively in a 1, 2 (top to back) manner. It is understood by one skilled in the art that for such tetrads that include a vinyl aromatic monomer other than styrene and an α-olefin other than ethylene, that the ethylene tetrad / vinyl aromatic monomer / vinyl aromatic monomer / ethylene will increase to carbon 13 NMR peaks similar but with slightly different chemical changes. These interpolymers can be prepared by conducting the polymerization at temperatures of from -30 ° C to 250 ° C in the presence of such catalysts as those represented by the formula / \ (ER?) R MR7 c wherein, each Cp is independently, each occurrence, a substituted p-cyclopentadienyl group attached to M; E is C or Si; M is a group IV metal; preferably Zr or Hf, more preferably Zr; each R is independently, each occurrence, H, hydrocarbyl, silahydrocarbyl, or hydrocarbylsilyl, containing up to 30 preferably from 1 to 20, more preferably from 1 to 10 silicon or carbon atoms; each R1 is independently, each occurrence, H, halo, hydrocarbyl, hydrocarbyloxy, silahydrocarbyl, hydrocarbylsilyl containing up to 30 preferably from 1 to 20 more preferably from 1 to 10 carbon atoms or silicon or two R1 groups together may be a 1, 3 -substituted hydrocarbyl butadiene C?.? 0; m is one or 2; and optionally, but preferably in the presence of an activating cocatalyst. Particularly, suitable substituted cyclopentadienyl groups include those illustrated by the formula: wherein each R is independently, each occurrence, H, hydrocarbyl, silahydrocarbyl or hydrocarbylsily, containing up to 30 preferably from 1 to 20 more preferably from 1 to 10 silicon or carbon atoms or two R groups together form a bivalent derivative of such group . Preferably, R independently each occurrence is (including where all isomers are appropriate) hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, benzyl, phenyl or silyl or (where appropriate) two such R groups are linked together forming a fused ring system such as indenyl, fluorenyl, tetrahydroindenyl, tetrahydrofluorophenyl, or octahydrofluorenyl. Particularly preferred catalysts include, for example, racemic zirconium dichloride- (dimethylisilanediyl) -bis- (2-methyl-4-phenylindenyl), 1,4-racehic-1,3-butadiene of racemic zirconium- (dimethylsilanediyl) -bis - (2-methyl-4-phenylindenyl), di-C 1-4 racemic zirconium alkyl- (dimethylsilanediyl) -bis- (2-methyl-4-phenylindenyl), di-C 1-4 racemic zirconium alkoxide- (dimethylsilanediyl) -bis- (2-methyl-4-phenylindenyl), or any combination thereof. It is possible to use the following forced geometry catalysts based on titanium, dimethyl of [N- (1,1-dimethylethyl) -1, 1 -dimethyl-1 - [(1, 2,3,4,5 -?) - 1, 5,6,7-tetrahydro-s-indacen-1 -yl] silanaminate (2 -) - N] titanium; dimethyl (1-indenyl) (tert-butylamido) dimethylsilane titanium; dimethyl ((3-tert-butyl) (1, 2,3,4, 5 -?) - 1-indenyl (tert-butylamido) dimethylsilane titanium; and dimethyl ((3-iso-propyl) (1, 2) , 3,4,5 -?) - 1 -indenyl) (tert-butyl amido) dimethylsilane titanium or any combination thereof The additional preparative methods for the interpolymers used in the present invention have been described in the literature. Grassi (Makromol, Chem., Volume 191, pages 2387 to 2396 [1990]) and D'Anniello et al (Journal of Applied Polymer Science, Volume 58, pages 1701 -1706 [1995]) reported the use of a catalytic system in based on methylalumoxane (MAO) and cyclopentadienyltitanium trichloride (CpTiCI3) to prepare an ethylene-styrene copolymer Xu and Lin (Polymer Prepints, Am. Chem. Soc, Div. Polvm Chem.) Volume 35, pages 686,687 [1994] have reported copolymerization using a MgCl2 / TiCl4 / NdCI3 / AI (iBu) 3 catalyst to give the random copolymers of styrene and propylene Lu et al (Journal of Applied Polymer Scien CE, Volume 53, pages 1453 to 1460 [1994] have described the co-polymerization of ethylene and styrene using a TiCl4 / NdCI3 / MgCl2 / AI (Et) 3 catalyst. Sernetz and Mulhaupt, (Macromol, Chem. Phys. V. 197, pp. 1071 -1073, 1997) have described the influence of polymerization conditions on the copolymerization of styrene with ethylene using Me2Si (Me4Cp) catalysts (N-tert- butyl) TiCl2 / methylaluminzane Ziegler-Natta. Ethylene-styrene copolymers produced by bridged metallocene catalysts have been described by Arai, Toshiaki and Suzuki (Polvmer Prepints, Am. Chem. Soc. Div. Polvm. Chem) Volume 38, pages 349, 350 [1997] and in the U.S. Patent No. 5,652,315, issued to Miitsui Toatsu Chemicals, Inc. The manufacture of α-olefin ether / aromatic vinyl monomer polymers such as propylene / styrene and butene / styrene are described in U.S. Patent No. 5,244,996, issued to Mitsui Petrochemical Industries Ltd or as described in DE 197 1 1 339 A1 for Denki Kagaku Kogyo KK. Also, although of high isototacticity and therefore not "substantially random", the ethylene-styrene random copolymers as described in Polymer Prepints Vol. 39 No. 1 March 1998 by Toru Aria et al, can also be used as components of mixture for the foams of the present invention. While preparing the substantially random interpolymer, an amount of aromatic vinyl homopolymer can be formed due to the homopolymerization of the vinyl aromatic monomer at elevated temperatures. The presence of aromatic vinyl homopolymer is generally not harmful for the purposes of the present invention and can be tolerated. The aromatic vinyl homopolymer can be separated from the interpolymer, if desired, by extraction techniques such as selective precipitation of the solution with a non-solvent for either the interpolymer or the vinyl aromatic homopolymer. For the purposes of the present invention, it is preferred that no more than 30 weight percent, preferably less than 20 weight percent based on the total weight of the atactic vinyl aromatic homopolymer interpolymers, be present. The mixture of polystyrene and ethylene-styrene interpolymer of the present invention can be prepared by any of the suitable means known in the material, such as, but not limited to, dry blending into a tablet form in the desired proportions followed by mixing by melting in a screw extruder, Banbury mixer or the like. The dry-mixed pellets can be processed directly by melting into a final solid state article, by, for example, injection molding. Alternatively, the mixtures can be made by direct polymerization, without the isolation of the components of the mixture, using, for example, two or more catalysts in a reactor, or by using a single catalyst and two or more reactors in series or in parallel. Preparation of the Foams of the Present Invention In the process of the present invention, a screw type extruder is preferably used. Such an extruder typically comprises a series of sequential zones including a feed zone, melting and compression zones, a measurement zone, and a mixer zone. The extruder barrier can be provided with conventional electric heaters for zone temperature control. An inlet is provided to add a blowing agent to the polymer mixture in the extruder barrier between the measuring and mixing zones. The blowing agent is composed in the polymer mixture to form a flowable gel. The discharge end of the mixing zone of the extruder is connected, through a cooling zone, to a nozzle orifice. The hot polymer gel is cooled and then passed through the nozzle orifice where the blowing agent is activated and the polymer gel expands to form a foam. As the foaming extrusion is formed, it is conducted away from the nozzle and allowed to cool and harden. In practice, the temperatures of the extruder zones are maintained at a temperature between 160 ° C and 230 ° C, and the temperature in the cooling zone is maintained at a temperature between 1 10 ° C and 135 ° C. The compositions of the present invention can be used to form extruded thermoplastic polymer foam, expandable thermoplastic foam beads, or expandable thermoplastic foams, and molded articles formed by expansion and / or coalescence or bonding of those particles. The foams can take any known physical configuration, such as extruded sheet, rod, board, films and profiles. The structure of the foam can also be formed by molding expandable beads in any of the above configurations or any other configuration. The foams may, if required for purposes of rapid solidification and to achieve accelerated release of the blowing agent, be modified by introducing a multiplicity of channels or perforations in the foam that extend from one surface to the foam, the channels being free of direction. with respect to the longitudinal extension of the foam. Excellent teachings of such modifications are described in U.S. Patent No. 5,424,016, WO 92/19439 and WO 97/22455. The foam structures can be made by conventional extrusion foaming processes. The present foam is generally prepared by melt blending, in which the vinyl aromatic polymer material and one or more substantially random interpolymers are heated together to form a fused or plasticized polymer material, which incorporates therein a blowing agent for form a foamable gel, and extrude the gel through a nozzle to form the foam product. Before extruding from the nozzle, the gel is cooled to an optimum temperature. To make a foam, the optimum temperature is at or above the glass transition temperature of the blends or melting point. For the foams of the present invention, the optimum foaming temperature is in the range in which the foam does not collapse. The blowing agent can be incorporated or mixed in the fused polymer material by any means known in the art such as with an extruder, mixer, modifier or the like. The blowing agent is mixed with the polymer material fused at a high enough pressure to prevent substantial expansion of the fused polymer material and to generally disperse the blowing agent homogeneously therein. Optionally, a nucleator can be mixed in the fused polymer or mixed dry with the polymer material before plasticizing or fusing. Substantially random interpolymers can be mixed in echo with the polymer material before switching to the extruder, or charged to the extruder in the form of a polymer concentrate or an interpolymer / color pigment carrier material. The foamable gel is typically cooled to a lower temperature to optimize the physical characteristics of the foam structure. The gel can be cooled in the extruder or other mixer device or in separate chillers. The gel is then extruded or transported through a nozzle of the desired shape to a zone of reduced or reduced pressure to form the foam structure. The lower pressure zone is at a pressure lower than that in which the foamable gel is maintained prior to extrusion through the nozzle. The lower pressure may be superatmospheric or subatmospheric (vacuum), but is preferably at an atmospheric level. The present foam structures can be formed into a coalesced filament shape by extruding the compositions of the present invention through a multi-orifice nozzle. The holes are installed so that contact between the adjacent streams of the fused extrudate occurs during the foaming process and the contact surfaces adhere to each other with sufficient adhesion to result in a unitary foam structure. The fused extruded streams emerging from the nozzle take the form of filaments or profiles, which desirably foamed, coalesce and adhere to each other to form a unitary structure. Desirably, the coalesced individual strands or filaments should remain adhered in a unitary structure to avoid delamination of the strand under stresses encountered in the preparation, formation and use of the foam. Apparatus and method for producing foam structures in coalesced filament form are noted in US Patents. Nos. 3,573, 152 and 4,824,720.

The foam structures present can also be formed by an accumulation extrusion process as seen in the U.S. Patent. No. 4,323,528. In this process, the low density foam structures having transverse, lateral, long areas will be prepared by: 1) forming under pressure a gel of the compositions of the present invention and a blowing agent at a temperature at which the viscosity of the gei it is sufficient to retain the blowing agent when the gel is allowed to expand; 2) Extrude the gel in a conservation zone maintained at a temperature and pressure that does not allow the gel to foam, the conservation zone having an outlet nozzle that defines an orifice opening in a lower pressure zone at which the gel foam and a step that can be opened, which closes the nozzle orifice; 3) periodically open the step; 4) substantially applying a mechanical pressure concurrently by a movable piston in the gel to expel it from the conservation zone through the orifice nozzle towards the lower pressure zone, a velocity greater than that, at which the substantial foaming at the hole, nozzle occurs and less than that, to which the irregularities in cross-sectional area or shape occur; and 5) allowing the ejected gel to expand without limitation in at least one dimension to produce the foam structure. The foam structures present can also be used to make foam films for labeling bottles and other containers using either a cast film or blown film extrusion process. The films can also be made by a co-extrusion process to obtain foam in the core with one or two surface layers, which may or may not be comprised of the polymer compositions used in the present invention. Blowing agents useful in making the foams present include inorganic blowing agents, organic blowing agents, and chemical blowing agents. Suitable inorganic blowing agents include nitrogen, sulfur hexafluoride (SF6), argon, water, air and helium. Organic blowing agents include carbon dioxide, aliphatic hydrocarbons having 1-9 carbon atoms, aliphatic alcohols having 1 -3 carbon atoms, and partially or fully halogenated aliphatic hydrocarbons having 1-4 carbon atoms. The aliphatic hydrocarbons include methane, ethane, propane, n-butane, isobutane, n-pentane, isopentane and neopentane. The aliphatic alcohols include methanol, ethanol, n-propanol and isopropanol. The full and partially halogenated aliphatic hydrocarbons include fluorocarbons, chlorocarbons, and chlorofluorocarbons. Examples of fluorocarbons include methyl fluoride, perfluoromethane, ethyl fluoride, (1, 1 -difluoroetano (HFC-1 52a), fluoroethane (HFC-161), 1, 1, 1-trifluoroethane (HFC-143a), 1, 1 1, 2-tetrafluoroethane (HFC-134a). 1, 1, 2,2-tetrafluoroethane (HFC-134), 1, 1, 1, 3,3-pentafluoropropane, petafluoroetano (HFC-125), difluoromethane (HFC-32 ), perfluoroethane, 2,2-difluoropropane, 1, 1, 1 - trifluoropropane, perfluopropano, dichloropropane, difluoropropane, perfluorobutane, perfluorocyclobutane chlorofluorocarbons and partial or fully halogenated chlorocarbons for use in this invention include methyl chloride, methylene chloride. ethyl chloride, 1, 1, 1-trichloro-ethane, 1, 1-dichloro-1 -fluoroetano (HCFC-141 b), 1 -chloro-1, 1 -difluoroetano (HCFC-142b), chlorodifluoromethane (HCFC-22 ), 1,1-dichloro-2,2,2-trifluoroethane (HCFC-123) and 1-chloro-1,2,2,2-tetrafluoroethane (HCFC-124) Fully halogenated chlorofluorocarbons include trichloromide nofluorometano (CFC-1 1), dichlorodifluoromethane (CFC-12), trichloro-trifluoroethane (CFC-1 13), dichlorotetrafluoroethane (CFC-1 14), chloroheptafluoropropane and dichlorohexafluoropropane. Chemical blowing agents include azodicarbonamide, azodiisobutyronitrile, benzenesulfonhydrazide, 4,4-oxybenzenesulfonyl-semicarbazide, p-toluene sulfonyl semi-carbazide, barium azodicarboxylate, N, N'-dimethyl-N, N'-dinitroso-terephthalamide, trihydrazino triazine and mixtures of citric acid and bicarbonate of sodium such as the various products sold under the name Hydrocerol ™ (a product and trademark of Boehringer Ingelheim). All of these blowing agents can be used as single components or any combination mixture thereof, or in mixtures with other co-blowing agents. The blowing agent used in the present invention must be capable of ensuring the formation of a foam with the desired open cell size and cell size. Preferred blowing agents for use in the present invention include 1,1-difluoroethane (HFC-152a), 1,1,1-tetrafluoroethane (HFC-134a), carbon dioxide, and water. Carbon dioxide is the preferred blowing agent, and can be used either alone or in combination with the other blowing agents or with mixtures thereof. The amount of blowing agent incorporated in the polymer fused material to make a polymer gel forming the foam is from 0.5 to 5.0 grams-moles per kilogram of polymer, preferably from 0.2 to 4.0 grams-moles per kilogram of polymer and more preferably from 0.5 to 3.0 grams-moles per kilogram of polymer. The use of a relatively small amount of blowing agent allows the formation of a foam with a high open cell content. In addition, a nucleating agent can be added in order to control the size of the foam cells. Preferred nucleating agents include organic substances such as calcium carbonate, talc, clay, silica, barium stearate, calcium stearate, diatomaceous earth, and mixtures of citric acid and sodium bicarbonate. The amount of nucleating agent employed may vary from 0 to 5 parts by weight per hundred parts by weight of a polymer resin. The preferred range is from 0 to 3 parts by weight. Various additives can be incorporated into the present foam structure such as inorganic fillers, pigments, dyes, antioxidants, acid cleaners, ultraviolet absorbers, flame retardants, processing aids, extrusion aids, permeability modifiers, antistatic agents, and other polymers. thermoplastics. Examples of permeability modifiers include but are not limited to glycerol monoesters. These monoesters can also serve to reduce the static during the manufacture of the foam. Examples of other thermoplastic polymers include copolymer or alkenyl aromatic homopolymers (having a molecular weight of 2,000 to 50,000) and ethylenic polymers. Properties of the Interpolymers and Mixture Compositions Used to Prepare the Foams of the Present Invention. The polymer compositions used to prepare the foams of the present invention comprise from 30 to 99.5, preferably from 50 to 99.5, more preferably from 80 to 99.5 weight percent (based on the combined weights of substantially random interpolymer and the aromatic homopolymers of alkenyl or copolymer) of one or more aromatic alkenyl homopolymers or copolymers. The molecular weight distribution (Mw / Mn) of the aromatic alkenyl copolymers or homopolymers used to prepare the foams of the present invention is from 2 to 7. The molecular weight (Mw) of the aromatic alkenyl copolymers or homopolymer used to prepare the foams of the present invention is from 100,000 to 500,000, preferably from 120,000 to 350,000, more preferably 1 30,000 to 325,000. The alkenyl aromatic polymer material used to prepare the foams of the present invention comprises more than 50 and preferably more than 70 weight percent aromatic monomeric alkenyl units. More preferably, the alkenyl aromatic polymer material is completely comprised of alkenyl aromatic monomer units. The polymer compositions used to prepare the foams of the present invention comprise from 0.5 to 70, preferably from 0.5 to 50, more preferably from 0.5 to 20 weight percent, (based on the combined weights of the substantially random interpolymers and the copolymers or aromatic alkenyl homopolymers), of one or more substantially random interpolymers. This substantially random polymer used to prepare the foams of the present invention usually contends from 0.5 to 65, preferably from 15 to 50, more preferably from 30 to 50 mole percent of at least one vinylidene or cycloaliphatic or aliphatic vinyl monomer or monomer vinylidene or vinyl aromatic, or combination thereof and from 35 to 95.5, preferably from 50 to 85, more preferably from 50 to 70 percent mol of ethylene or at least one α-olefin having from 3 to 20 carbon atoms , or combination thereof. The melt index (I) of the substantially random interpolymer used to prepare the foams of the present invention is from 0.1 to 50, preferably from 0.3 to 30, more preferably from 0.5 to 10 g / 10 min. The molecular weight distribution (Mw / Mp) of the substantially random interpolymer used to prepare the foams of the present invention is from 1.5 to 20, preferably from 1.8 to 10, more preferably from 2 to 5. In addition, the minor amounts of alkenyl aromatic copolymers or homopolymers having a molecular weight of 2,000 to 50,000, preferably from 4,000 to 25,000 may be added in an amount not exceeding 20 weight percent (based on the combined weights of substantially random interpolymer and the various aromatic homopolymers or copolymers of alqueniio Parameters of the Process Used to Prepare the Foams of the Present Invention The process for making the open cell foam of the present invention comprises the steps of mixing together, the aromatic alkenyl polymer, preferably polystyrene; and the substantially random interpolymer, preferably a substantially random ethylene-styrene interpolymer and adding the blowing agent to the mixture to form a gel. The gel is then extruded through a nozzle to form the foam. The temperature at which the foam is formed (foaming temperature) is between 1 10 ° C and 135 ° C, preferably between 1 15 and 1 35, more preferably between 120 and 135 ° C, and is from 3 ° to 15 ° C. C lower than the highest foaming temperature for the corresponding open cell foam. Properties of the Foams of the Present Invention The foam has a density of from 10 to 200, preferably from 15 to 100 and more preferably from 20 to 60 kilograms per cubic meter according to ASTM D-1622-88. The foam has an average cell size of from 5 to 2,000, preferably from 20 to 1,000, and more preferably 50 to 500 microns according to ASTM D3576-77. The foam has a water absorption value of from 5 to 25 g / g of foam. The open cell foam contains at least 20 percent open cells. More preferably, the foam contains at least 50 percent open cells, and more preferably, at least 80 percent open cells as measured according to ASTM D 2856-A. The foams may be produced in the form of beads, boards, series, sheets and are particularly suited to be formed into a board or sheet, desirably having a thickness or smaller dimension in cross section of 1 mm or more, preferably 2 mm or more, or more preferably 2.5 mm or more. The width of the foam could be as long as 1.5 meters.

The foams produced in accordance with the present invention can be used in a number of applications including application of noise absorption and fluid absorption. The foams of the present invention can be used in a variety of other applications such as accumulator packaging, recreational and athletic products, egg cartons, meat trays, construction and structuring (e.g., thermal insulation, acoustic insulation), pipe insulation , sealing gaskets, antivibration chocks, luggage wraps, bearing shoe soles, gymnastic meshing, insulating blankets for cold stores, box inserts, deployment foams, etc. Examples of building and structuring applications include external wall cladding (local thermal insulation), roofing, foundation insulation, and under-flooring of resident wood. Other applications include insulation for cooling, flotation applications (eg, body members, flotation and platform dams) as well as various grafting and floral applications. However, it should be clear that the foams of this invention will not be limited to the above mentioned applications. The following examples are illustrative of the invention, but are not constructed as limiting the scope thereof in any way. EXAMPLE Test Methods a) Melt Flow and Density Measurements The molecular weight of the substantially random interpolymers used in the present invention is conveniently indicated using a melt index measurement according to ASTM D-1238, Condition 190 ° C / 2.16 kg (formally known as "Condition (E) ny also known as l2), was determined.The melt index is inversely proportional to the molecular weight of polymer.Thus, the higher the lower molecular weight is the index of fusion, although the relationship is not linear.Also useful to indicate the molecular weight of the substantially random interpolymers used in the present invention is the Gofftert melt index (G, cm3 / 10 min) which is obtained in a similar manner as the melt index (12) using the ASTM D1238 method for automatic plastomers, with the melt density set at 0.7632, the density of polyethylene melting at 190 ° C. The ratio of the melt density to the styrene content for ethylene-styrene interpolymers was measured, as a function of the total styrene content, at 190 ° C over a range of 29.8 percent a 81.1 percent by weight of styrene. The levels of atactic polystyrene in these samples were typically 10 percent or less. The influence of atactic polystyrene was assumed to be minimal due to the lower levels. Also, the fusion density of atactic polystyrene and the melting densities of samples with high total styrene are very similar. The method used to determine the melt density employed a Gottfert melt index machine with a melting density parameter set at 0.7632 and the collection of fused filaments as a function of time while the weight of l2 was in force. The weight and time for each fused filament was recorded and normalized to produce the mass in grams per 10 minutes. The calculated melt index value l2 of the instrument was also recorded. The equation used to calculate the current melting density is d = do.7632 x I2 I2 Gottfert where d0 76.2 = 0.7632 and l2 Gottfert = displayed melt index. An adjustment to at least the linear square of melt density calculated against the total styrene content leads to an equation with a correlation coefficient of 0.91 for the following equation: d = 0.00299 x S + 0.723 where S = styrene weight percentage in the polymer. The total styrene ratio with the melt density can be used to determine the current melt index value, using these equations if the styrene content is known. So, for a polymer that is 73 percent total styrene content with a measured melt flow (the "Gottfert number"), the calculation becomes: x = 0.00299 * 73 + 0.723 = 0.9412 where 0.9412 / 0.7632 = l2 / G # (measured) = 1 .23 b) Styrene Analysis The styrene content of the interpolymer and the concentration of atactic polystyrene was determined using proton nuclear magnetic resonance (1 H NMR). All proton NMR samples are prepared in 1,1,1,2-tetrachloroethane-d 2 (TCE-d 2). The resulting solutions were 1.6 and 3.2 percent polymer by weight. The melt index (12) was used as a guide to determine the concentration of the sample. In this way, when the l2 was greater than 2 g / 10 min, 40 mg of interpolymer were used; with one l2 between 1.5 and 2 g / 10 min, 30 mg of interpolymer were used; and when 12 was less than 1.5 g / 10 min, 20 mg of interpolymer was used. The interpolymer was weighed directly into 5 mm sample tubes. An aliquot of 0.75 mL of TCE-d2 was added by injection and the tube was covered with a layer of forced-fit polyethylene. The samples were heated in water balo at 85 ° C to soften the interpolymer. To provide mixing, the covered samples were occasionally brought to reflux using a heat gun. The proton NMR spectra were accumulated in a Varian VXR 300 with the test probe at 80 ° C, and made reference to the residual protons of TCE-d2 at 5.99 ppm. The delays varied between 1 second, and the data was collected in triplicate in each sample. The following instrumental conditions were used for the analysis of the interpolymer samples: Variant VXR-300, 1H standard: Exploration Amplitude, 500 Hz Acquisition Time, 3,002 sec Impulse Amplitude, 8 μsec Frequency, 300 MHz Delay, 1 sec Transients, 16 The total analysis time per sample was 1 0 minutes. Initially, a 1H NMR spectrum for a polystyrene sample, having a molecular weight (Mw) of 192,000 was acquired with a delay of one second. The protons were "marked": b, branch; a, alpha; or, ortho; m, goal; p, for, as shown in Figure 1.

Figure 1 Integrals were measured around the protons marked in Figure 1: 'A' designates aPS. The integral A7 1 (aromatic, approximately 7.1 ppm) is believed to be the three ortho / para protons; an integral A6.6 (aromatic, approximately 6.6 ppm) the two meta protons. The two aliphatic protons marked a resonance at 1.5 ppm; and the only labeled proton b is at 1.9 ppm. The aliphatic region was integrated from 0.8 to 2.5 ppm and is referred to as Aa .. the theoretical proportion for A7.? : A6 e: Aa? is 3: 2: 3 or 1 .5: 1: 1 .5 and correlated very well with the observed proportions for the polystyrene sample for several 1 second delays. The proportion calculations used to verify the integration and verify the peak assignments were made by dividing the appropriate integral by the integral A6.β Proportion Ar is A7 .. / A6.6. Region A6.6 was assigned a value of 1. Proportion A1 is integral Aa ./ A6.ß- All spectra collected have the expected 1.5: 1: 1 .5 integration ratio of (o + p): m: (a + b). The ratio of aromatic to aliphatic protons is 5 to 3. An aliphatic ratio of 2 to 1 is predicted based on the protons marked a and b, respectively in Figure 1. This ratio was also observed when the two aliphatic peaks were integrated separately. "For the ethylene / styrene interpolymers, the 1H NMR spectra using a one second delay had C7, C6.6 and Ca? Integrals defined, such that the integration of the peak at 7.1 ppm included all the protons aromatics of the copolymer as well as the protons or & p of aPS In the same way, the integration of the aliphatic region Ca? into the spectrum of the interpolymers included aliphatic protons of both aPS and the interpolymer with signal results without clear petrolatum of any polymer The integral of the peak at 6.6 ppm of C6 6 is resolved from other aromatic signals and is thought to be due only to aPS homopolymer (probably target protons). (The peak assignment for atactic polystyrene at 6.6 ppm (integral A6.ß) is made on the basis of the comparison of the authentic sample of polystyrene having a molecular weight (Mw) of 192,000.This is a reasonable assumption since, at very low levels of atactic polystyrene, only e a very weak signal is observed. Therefore, the phenyl protons of the copolymer should not contribute to this signal. When this assumption, A6.6, becomes the basis for quantitatively determining the aPS content. The following equations were then used to determine the degree of styrene incorporation in the ethylene / styrene interpolymer samples: (C Phenyl) = C7 .1 + A7.1 - (1.5 x Aß.β) (C Aliphatic) = Caí-d • 5 x Aß.ß) Se = (C Phenyl) / 5 ec = (C Aliphatic) - - (3 x sc)) / 4 E = = ec / (ec + Se) Se = sc / ( ec + Se) and the following equations were used to calculate the mole percent of ethylene and polystyrene in the interpolymers. wherein: sc and ec are proton fractions of styrene and ethylene in the interpolymer, respectively, and Sc and E are mole fractions of styrene monomer and ethylene monomer in the interpolymer, respectively. The weight percent of aPS in the interpolymers was then determined by the following equation: The total styrene content was also calculated by quantitative Fourier Transform Infrared (FTIR) spectroscopy. Experimental Procedure for Open Cell Content The open cell test was based on a liquid intrusion technique. Volume (V) and dry weight (DW) for each foam sample was recorded. The foam samples are placed in the bottom of a desiccator, below the desiccator plate. The piping was used to connect the desiccator to a filter flask used with a liquid container. Another filter flask used as a liquid trap was placed between the liquid container and a vacuum pump that was used to create the pressure gradient through the system. The liquid used in this test was water with 0.75 percent of a common dish soap (active ingredient - water-soluble surfactant which is sodium laurel sulfate). The reduced surface tension of this liquid ensures the wetting of the polymer surface. The pump is stable to the desired vacuum (>; 600 torr) and the system pressure was allowed to stabilize (approximately 10 minutes). Once stable, the plastic tube from the liquid container to the desiccator was inserted into the liquid. The vacuum pump was then switched off, introducing atmospheric pressure into the system and forcing liquid from the liquid container into the desiccator. Note: There must be enough liquid in the container to cover the desiccator plate. After about 1.5 minutes, the sample was removed from the liquid and dried with a paper towel to remove any excess water on the surface. The sample was weighed to determine the amount of liquid absorbed and the wet weight (WW) was recorded. The waqs of open cell content (in percent of open cell) were then calculated from the following formula: Open Cell Percentage = 1 00 * (WW-DW) / (V-DW / d) where d is the polymer density in g / cm3.

Experimental Procedure for Atmospheric Fluid Absorbency In this test, the dry weight of the foam sample was recorded. The sample was placed in a low surface tension liquid soap solution (surface tension <40 dynes / cm). The sample was allowed to settle in the solution for 24 hours. After 24 hours, the sample was removed from the liquid and dried with a paper towel to remove any excess water on the surface. The sample was weighed to determine the amount of liquid adsorbed. The results are reported in terms of grams of liquid absorbed per gram of foam. Preparation of Substantially Random Ethylene / Styrene Interpolymers (ESl's) 1 -3 • Polymerization experiments were perfd using a stirred 1-gallon Autoclave Engineers reactor. The reactor was charged with the desired amounts of cyclohexane and styrene solvent using a mass flow meter. Hydrogen was added by expansion of a 75 mL vessel and measured as a pressure drop in this vessel (psig delta), then the reactor was heated to the polymerization temperature of 60 ° C and saturated with ethylene at the desired pressure . The catalyst was prepared in an inert atmosphere glove box by successively adding catalyst hydrocarbon solutions (titanium (N-1, 1-dimethylol) dimethyl (1 - (1, 2,3,4,5 -?) - 2 , 3,4,5-tetramethyl-2,4-cyclopentadien-1-l) silanaminate)) (2-) N) -dimethyl, CAS # 1 35072-62-7) and the tris (pentafluorophenyl) borane cocatalyst (CAS # 001 109-15-5) and a commercially modified methylaluminoxane available from Akzo Nobel as MMAO-3A (CAS # 146905-79-5) to sufficient additional solvent to give a total volume of 20 mL. The molar ratio TI: B: A1 was 1: 1.5: 20. The catalyst solution was then transferred by syringe to a catalyst addition cycle and injected into the reactor for about 20 minutes using a high pressure solvent flow. The polymerization was allowed to proceed for about 30 minutes while ethylene is fed on demand to maintain the desired pressure. The amount of ethylene consumed during the reaction was monitored using a mass flow measurement. The polymer solution was discharged from the reactor in a glass kettle purged with nitrogen. The polymer solution was discharged in a tray, isolated in methanol, filtered and then completely dried in a vacuum oven. The average process conditions for these samples are summarized in Table 1 and the polymer properties are summarized in Table 3. TABLE 1 Preparation of ESI 4 The ESI 4 interpolymer was prepared in a stirred 400-gallon semi-continuous loading reactor (1514 L). The reaction mixture consisted of approximately 250 gallons (946 L) of solvent comprising a mixture of cyclohexane (85 weight percent) and isopropane (1 5 weight percent), and styrene. Before the addition, the solvent, styrene and ethylene were purified to remove water and oxygen. The inhibitor in the styrene was also removed. The inerts were removed by purging the container with ethylene. The container was then controlled by pressure to a reference point with ethylene. Hydrogen was added to control the molecular weight. The temperature in the vessel was controlled to the reference point by varying the water temperature of the outer jacket in the vessel. Prior to polymerization, the vessel was heated to the desired operating temperature and catalyst components Titanium: (N-1, 1-dimethylethyl) dimethyl) 1 - (1, 2,3,4,5-eta) -2 , 3,4,5-tetramethyl-2,4-cyclopentadien-1-yl) silanaminate)) (2-) N) -dimethyl, CAS # 135072-62-7 and Tris (pentafluorofeniI) boron, CAS # 001 109- 1-5, modified methylaluminoxane Type 3A, CAS # 146905-79-5 was controlled by flow, in a mole ratio base of 1/3/5, respectively, combined and added to the vessel. After stirring, the polymerization was allowed to proceed with ethylene supplied to the reactor as required to maintain the container pressure. In some cases, hydrogen was added to the upper space of the reactor to maintain a mole ratio with respect to the ethylene concentration. At the end of the step, the catalyst flow was stopped, ethylene was removed from the reactor, approximately 1000 ppm of anti-oxidant Irganox .T1 M "1 1 010 (trade name of Ciba Geigy Corp) was then added to the solution and the polymer The resulting polymers were isolated from the solution either by steam distillation in a vessel or by the use of a devolatilization extruder.In the case of steam distillate material, further processing was required in the extruder as the equipment to reduce residual moisture and any unreacted styrene The specific preparation conditions for the interpolymer are summarized in Table 2 and the properties in Table 3. TABLE 2 TABLE 3 1 Determined by ASTM D-1238 at 1 90 ° C / 2 kg The foams are prepared according to the present invention using ethylene-styrene interpolymer resins which were prepared as described above. Example 1 A polymer blend was prepared by mixing a granular polystyrene resin having a weight average molecular weight of 200,000 with the ESI-3 resin. The level of ESI-3 was varied from 1 to 5 weight percent. The ES interpolymer was made from a 10% by weight concentrate by pre-mixing the resin with the polystyrene resin using a twin screw extruder. The mixture was then fed to the hopper of an extruder and extruded at a uniform rate of 4.5 kg / hr. The apparatus used in this Examples is a 38 mm (1 -1 / 2") screw extruder having additional zones of mixing and cooling at the end of the usual areas of feeding, measuring and mixing. is provided at the extruder barrier between the measuring and mixing zones A nozzle orifice having a rectangular shaped opening is included at the end of the cooling zone The height of the opening, hereinafter referred to as an opening The nozzle is adjustable while its amplitude is fixed at 6.35 mm The temperatures maintained in the zones of the extruder were 160 ° C in the feeding zone, 190 ° C in the transition zone, 193 ° C in the fusion zone, 204 ° C in the measuring zone and 106 ° C in the mixer zone The carbon dioxide was injected at the injection point at a uniform speed so that the level becomes approximately 4.92 parts per hundred parts of waste. The temperature of the cooling zone is gradually reduced by decreasing the temperature of the cooling fluid (oil) to cool the polymer / blowing agent (gel) mixture to the optimum foaming temperature. The temperature of the nozzle opening was maintained at approximately the same temperature as the temperature of the cooling zone. The gel temperature at which a good foam was made varies from 129-130 ° C. The thickness of the resulting foams vary from 7.1 to 9.1 mm and the width of the foams varies from 22.5 to 24.7 mm. As shown in Table 4, the foam density decreases slightly as the level of ESI resin increases. The cell size remains relatively unchanged. As can be seen, the ESI resin has the most pronounced effect on the open cell content. The open cell content was shown to increase as the ESI level is increased. The open cell contents are as high as 88 percent were achieved. * not an example in this invention (1) Interpolymer parts of ethylene-styrene mixed in per hundred parts of mixture (2) Cooling oil temperature circulating cooling section (3) Cell size as determined by ASTM D 3576 (4) Open cell content of the foam body as determined by ASTM D 2856-A Example 2 The foams were produced as in Example 1, but using the ESI-2 resin (Table 2). The thickness of the foams varied from 5.8 to 7.6 mm and the width of the foams ranged from 24.2 to 26.0 mm. As shown in Table 5, the addition of 1-5 weight percent ESI resin resulted in foams having a high open cell content. TABLE 5 (1) Parts of ethylene-styrene interpolymer mixed in per hundred parts of mixture (2) Cooling oil temperature circulating cooling section (3) Cell size as determined by ASTM D 3576 (4) Open cell content of the foam body as determined by ASTM D 2856-A Example 3 The foams were produced as in Example 1 using the ESI-1 resin (Table 1). The thickness of the resulting foams varied from 7.6 to 7.9 mm and the width of the foams ranged from 23.6 to 23.9 mm. As shown in Table 6, the addition of 2-5 weight percent ES resin results in foams having a high open cell content. TABLE 6 (1) Parts of ethylene-styrene interpolymer mixed in per hundred parts of mixture (2) Cooling oil temperature circulating cooling section (3) Cell size as determined by ASTM D 3576 (4) Open cell content of the foam body as determined by ASTM D 2856-A Example 4 The foams were prepared as in Example 1 using a mixture of polystyrene resin having a weight average molecular weight of 130,000 and an ethylene-styrene interpolymer which it has a styrene content of 81.5 percent (ESI-4 of Table 1). The carbon dioxide level was set at 3.46 pph. As can be seen in Table 7, at approximately the same foaming temperature, the open cell content increases and the foam density decreases as the level of copolymer ES is increased. It can also be observed that the foaming temperature has an effect on the content of the open cell (see series 4 and 5). Even at a significantly reduced foaming temperature of 124 ° C (series 5), the foam still shows 33 percent open cells. TABLE 5 (1) Parts of ethylene-styrene interpolymer mixed in per hundred parts of mixture (2) Cell size as determined by ASTM D 3576 (3) Open cell content of the foam body as determined by ASTM D 2856-A Examples 5-12 Preparation of ESI # 's 5-8 ESI #' s 5-8 are substantially random ethylene / styrene interpolymers prepared using the following catalyst and polymerization procedures. Preparation of Catalyst A (dimethylN-d, 1-dimethylethyl) -1, 1-dimethyl-1-f (1, 2,3,4,5-h) -1, 5,6,7-tetrahydro-3-phenyl-s -indazen-1-inlalanaminate (2 -) - Nl-tjtanium) 1) Preparation of 3,5,6,7-Tetrahydro-s-Hydrindacen-1 (2H) -one Indane (94.00 g, 0.7954 moles) and 3-Chloropropionyl chloride (100.99 g, 0.7954 moles) was stirred to CH2Cl2 (300 mL) at 0 ° C as AICI3 (130.00 g, 0.9750 moles) was added slowly under nitrogen flow. The mixture was allowed to stir at room temperature for 2 hours. The volatiles were removed. The mixture was then cooled to 0 ° C and concentrated H2SO4 (500 mL) was added slowly. The formation solid should often be broken with a spatula as agitation is lost early in this stage. The mixture was left under nitrogen overnight at room temperature. The mixture was then heated until the temperature readings reached 90 ° C. These conditions were maintained for a period of 2 hours, during which periodically a spatula was used to stir the mixture. After the reaction period, crushed ice was placed in the mixture and moved around. The mixture was then transferred to a beaker and rinsed intermittently with H2O and diethyl ether and then the fractions were filtered and combined. The mixture was rinsed with H2O (2 x 200 mL). The organic layer was then separated and the volatiles removed. The desired product was then isolated by recrystallization of hexane at 0 ° C as pale yellow crystals (22.36 g, 16.3 percent product). 1H NMR (CDCl 3): d2.04-2.19 (m, 2H), 2.65 (t, 3 JHH = 5.7 Hz, 2H), 2.84-3.0 (m, 4H), 3.03 (t, 3JHH = 5.5 Hz, 2 H) , 7.26 (s, 1 H), 7.53 (s, 1 H). 13C NMR (CDCI3): d25.71, 26.01, 32.19, 33.24, 36.93, 1 18.90, 122.16, 135.88, 144.06, 152.89, 154.36, 206.50. GC-MS: Calculated for C12H12O 172.09, found 172.05 2) Preparation of 1, 2,3,5-Tetrahydro-7-phenyl-s-indacen 3,5,6,7-Tetrahydro-s-Hidrindacen-1 (2H) -one (12.00 g, 0.6967 moles) was stirred in diethyl ether (200 mL) at 0 ° C as PhMgBr was added slowly (0.105 moles, 35.00 mL of 3.0 M solution in diethyl ether). This mixture was allowed to stir overnight at room temperature. After the reaction period, the mixture was cooled by pouring it on ice. The mixture was then acidified (pH = 1) with HCl and stirred vigorously for 2 hours. The organic layer was then separated and rinsed with H 2 O (2 x 100 mL) and then dried over MgSO. Filtration followed by removal of the volatiles resulted in the isolation of the desired product as a dark oil (14.68 g, 90.3 percent product). 1 H NMR (CDCl 3): d 2.0-2.2 (m, 2 H), 2.8-3.1 (m, 4 H), 6.54 (s, 1 H), 7.2-7.6 (m, 7 H).

GC-MS: Calculated for C? 8H? 6 232.1 3, found 232.05. 3) Preparation of 1, 2,3,5-Tetrahydro-7-phenyl-s-indacen, lithium salt 1, 2,3,5-Tetrahydro-7-phenyl-s-indacen (14.68 g, 0.06291 moles) stirred in hexane (150 mL) as nBuLi (0.080 moles, 40.00 mL of 2.0 M solution in cyclohexane) was added slowly. This mixture was allowed to stir overnight. After the reaction period, the solid was collected through suction filtration as a yellow solid which is rinsed with hexane, dried under vacuum, and used without further purification or analysis (12.2075 g, 81.1 percent of product) 4) Preparation of Chlorodimethyl (1, 5,6,7-tetrahydro-3-phenyl-s-indacen-1-yl) silane. 1, 2,3,5-Tetrahydro-7-phenyl-s-indacene, dilithium salt (12.2075 g, 0.05102 mol) in THF (50 mL) was added dropwise to a solution of Me2SiCl2 (19.5010 g, 0.151 1 moles) in THF (100 mL) at 0 ° C. This mixture was then allowed to stir at room temperature overnight. After the reaction period, the volatiles were removed and the residue was extracted and filtered using hexane. Removal of the hexane resulted in the isolation of the desired product as a yellow oil (15.1492 g, 91.1 percent product). 1 H NMR (CDCl 3): d? .33 (s, 3 H), 0.38 (s, 3 H), 2.20 (p, 3 J H H = 7.5 Hz, 2 H), 2.9-3.1 (m, 4 H), 3.84 (s, 1 H), 6.69 (d, 3 JHH = 2.8 Hz, 1 H), 7.3-7.6 (m, 7H), 7.68 (d, 3JHH = 7.4 Hz, 2H) 13C NMR (CDCI3): d? .24, 0.38, 26.28, 33.05, 33.18, 46.13, 1 16.42, 1 19.71, 127.51, 128.33, 128.64, 129.56, 136.51, 141 .31, 141.86, 142.17, 142.41, 144.62 GC-MS: Calculated for C20H2.CISi 324.11, found 324.05 . 5) Preparation of N- (1, 1-Dimethylethyl) -1, 1-dimethyl-1- (1.Se ^ -tetrahydro-S-phenyl-s-indacen-li 'silanamine Chlorodimethyl (1, 5,6,7 -tetrahydro-3-phenyl-s-indacen-1-yl) silane (10.8277 g, 0.03322 mol) was stirred in hexane (150 mL) as NET3 (3.5123 g, 0.03471 mol) and.-Butylamine (2.6074 g, 0.03565 mol) were added. This mixture was allowed to stir for 24 hours. After the reaction period, the mixture was filtered and the volatiles were removed resulting in the isolation of the desired product as a dense red-yellow oil. (10.6551 g, 88.7 percent of product). 1H NMR (CDCl 3): d? .02 (s, 3H), 0.04 (s, 3H), 1.27 (s, 9H), 2.16 (p, 3JHH = 7.2 Hz, 2H), 2.9-3.0 (m, 4 H) ), 3.68 (s, 1H), 6.69 (s, 1H), 7.3-7.5 (m, 4H), 7.63 (d, 3JHH = 7.4 Hz, 2H) 3C NMR (CDCI3): d-0.32, -0.09, 26.28 , 33.39, 34.11, 46.46, 47.54, 49.81, 115.80, 119.30, 126.92, 127.89, 128.46, 132.99, 137.30, 140.20, 140.81, 141.64, 142.08, 144.83 6) Preparation of N- (1, 1-Dimethylethyl) -1, 1-dimethyl-1- (1,5,6,7-tetrahydro-3-phenyl-s-indacen-1-yl) si.anamine, dilithium salt N- (1,1-Dimethylethyl) -1,1- Dimethyl-1 - (1,5,6,7-tetrahydro-3-phenyl-s-indacen-1-yl) silanamine, (10.6551 g, 0.02947 mol) was stirred in hexane (100 mL) as it was added slowly nBuLi (0.070 moles, 35.00 mL of 2.0 M solution in cyclohexane). This mixture was then allowed to stir overnight, during which time none of the salts were ground out of the dark red solution.

After the reaction period, the volatiles were removed and the residue rinsed rapidly with hexane (2 x 50 mL). The dark red residue was then pumped dry and used without further purification or analysis (9.6517 g, 87.7 percent product). 7) Preparation of Dichloro [N- (1,1-dimethylethyl) -1,1-dimethyl-1 - [(1, 2,3,4,5-h) -1,5,6,7-tetrahydro-3 phenyl-s-indacen-1-yl) silanaminato (2 -) - N] titanium N- (1,1-dimethylethyl) -1, 1 -dimethyl-1 - (1, 5,6,7-tetrahydro-3) phenyl-s-indacen-1-yl) silanamine, dilithium salt (4.5355 g, 0.01214 mol) in THF (500 mL) was added dropwise to a mixture of TiCl 3 (THF) (4.5005 g, 0.01214 mol) in THF (100 mL). This mixture was stirred for 2 hours. PbCl2 (1.7136 g, 0.006162 moles) was then added and the mixture was allowed to stir for an additional hour. After the reaction period, the volatiles were removed and the residue was extracted and filtered using toluene. Removal of toluene resulted in the isolation of a dark residue. This residue was then mixed in hexane and cooled to 0 ° C. The desired product was then isolated through filtration as a dark brown crystalline solid (2.5280 g., 43.5 percent of product). 1 H NMR (CDCl 3): d? .71 (s, 3 H), 0.97 (s, 3 H), 1 .37 (s, 9 H), 2.02-2.2 (m, 2 H), 2.9-3.2 (m, 4 H) , 6.62 (s, 1 H), 7.35-7.45 (m, 1 H), 7.50 (t, 3JHH = 7.8 Hz, 2H), 7.57 (s, 1 H), 7.70 (d, 3JHH = 7.1 Hz, 2H) 7.78 (s, 1 H). 1 H NMR (C6D6): d? .44 (s, 3H), 0.68 (s, 3H), 1.35 (s, 9H), 1.6-1.9 (m, 2H), 2.5-3.9 (s). m, 4H), 6.65 (s, 1 H), 7.1 -7.2 (m, 1 H), 7.24 (t, 3JHH = 7.1 Hz, 2H), 7.61 (s, 1 H), 7.69 (s, 1 H) 7.77-7.8 (m, 2H). 13C NMR (CDCI3): d1.29, 3.89, 26.47, 32.62, 32.84, 32.92, 63.16, 98.25, 118.70, 121.75, 125.62, 128.46, 128.55, 128.79, 129.01, 134.11, 134.53, 136.04, 146.15, 148.93. 13C NMR (C6D6): d? .90, 3.57, 26.46, 32.56, 32.78, 62.88, 98.14, 119.19, 121.97, 125.84, 127.15, 128.83, 129.03, 129.55, 134.57, 135.04, 136.41, 147.24, 148.96. 8) Preparation of Dimethyl [N- (1,1-dimethylethyl) -1,1-dimethyl-1 - [(1,2,3,4,5-h) -1,5,6,7-tetrahydro-3 phenyl-s-indacen-1-yl) silanamine (2 -) - N] titanium Dichloro [N- (1,1-dimethylethyl) -1,1-dimethyl-1 - [(1,2,3,4, 5-h) -1,5,6,7-tetrahydro-3-phenyl-s-indacen-1-yl) silanaminate (2 -) - N] titanium (0.4970 g, 0.001039 moles) was stirred in diethylether (50 mL) as MeMgBr (0.0021 moles, 0.70 mL of 3.0 M diethylether solution) was added slowly. This mixture was then stirred for 1 hour. After the reaction period, the volatiles were removed and the residue was extracted and filtered using hexane. Removal of the hexane resulted in the isolation of the desired product as a golden yellow solid (0.4546 g, 66.7 percent product) 1H NMR (C6D6): d? .071 (s, 3H), 0.49 (s, 3H), 0.70 (s, 3H), 0.73 (s, 3H), 1.49 (s, 9H), 1.7-1.8 (m, 2H), 2.5-2.8 (m, 4H), 6.41 (s, 1H), 7.29 (t, 3JHH = 7.4 Hz, 2H), 7.48 (s, 1H), 7.72 (d, 3JHH = 7.4 Hz, 2H), 7.92 (s, 1H). 13C NMR (C6D6): d2.19, 4.61, 27.12, 32.86, 33.00, 34.73, 58.68, 58.82, 118.62, 121.98, 124.26, 127.32, 128.63, 128.98, 131.23, 134.39, 136.38, 143.19, 144.85. Polymerization for ESI # 's 5-6 ESl' s 5-6 were prepared in a continuously stirred tank reactor, Autoclave, with 6 gallon (22.7 L) oil jacket (CSTR). A stirrer magnetically coupled with Lighting A-320 impellers provided mixing. The reactor passed full liquid at 475 psig (3,275 kPa). The process flow is in the lower part and outside the upper part. . A heat transfer oil was circulated through the outer jacket of the reactor to remove some heat from the reaction. At the outlet of the reactor, a micromotion flow meter was found that measured the solution flow and density. All lines at the reactor outlet were run with 50 psi (344.7 kPa) of steam and were isolated. The toluene solvent was supplied to the reactor at 30 psig (207 kPa). The feed to the reactor was measured by a fixed mass meter Micro-Motion. A variable speed diaphragm pump controlled the feeding speed. In the solvent discharge of the pump, a side vapor was taken to provide fast flows for the catalyst injection line (1 Ib / hr (0.45 kg / hr)) and the reactor stirrer (0.75 Ib / hr (0.34 kg / hr.) These flows were measured by differential pressure flow meters and controlled by manually adjusting the micro-flow needle valves Unreacted styrene monomer was supplied to the reactor at 30 psig (207 kPa). The feed to the reactor was measured by a Micro-Motion mass flow meter, a variable speed diaphragm pump controlled the feed rate.

The styrene vapor was mixed with the remaining solvent stream. The ethylene was supplied to the reactor at 600 psig (4, 137 kPa). The ethylene stream was measured by a Micro-Motion mass flow meter just before the flow controlling the Search valve. A Brooks flow meter / controller was used to deliver hydrogen into the ethylene stream at the outlet of the ethylene control valve. The ethylene / hydrogen mixture is combined with the solvent / styrene stream at room temperature. The temperature of the solvent / monomer as it enters the reactor drops to ~ 5 ° C through an exchanger with -5 ° C of glycol in the outer jacket. This current entered the lower part of the reactor. The three-component catalyst system and its solvent flow also entered the reactor at the bottom but through a different port than the monomer stream. The Preparation of the catalyst components takes place in a glove box with an inert atmosphere. The diluted components were placed in cylinders with nitrogen bearings and charged to the operating tanks of the catalyst in the process area. From these operating tanks the catalyst was pressurized up with piston pumps and the flow was measured with Micro-Motion mass flow meters. These streams combine with each other and the solvent of the catalyst fluid just before entering through a single injection line in the reactor. The polymerization was stopped with the addition of agressive catalyst (water mixed with the solvent) in the product line of the reactor after the micromotion flow meter measured the density of the solution. Other polymer additives can be added with the aggressor catalyst. A static mixer in the line provided the dispersion of the agressive catalyst and the additives in the effluent stream of the reactor. This current then entered the post-reactor heaters that provide additional energy for the removal of solvent flow. This flow occurs as the effluent exits the post-reactor heater and the pressure drops from 475 psig (3, 275 kPa) below -250 mm absolute pressure in the pressure control valve of the reactor. This flow polymer entered a hot oil outer jacket devolatilizer. Approximately 85 percent of the volatiles were removed from the polymer in the devolatilizer. The volatiles leave the upper part of the volatilizer. The stream was condensed with an external glycol jacket exchanger and suction of an empty pump entered and discharged to a glycol outer jacket solvent and styrene / ethylene separation vessel. The solvent and styrene were removed from the bottom of the container and ethylene from the top. The ethylene stream was measured with a Micro-Motion mass flow meter and analyzed for its composition. The measurement of the ventilated ethylene plus a calculation of the gases dissolved in the solvent / styrene stream was used to calculate the ethylene conversion. The polymer separated from the devolatilizer was pumped out with a gear pump to a vacuum devolatilization extruder ZSK-30. The dried polymer exited the extruder as a single filament. This filament cooled as it was pushed through a water bath. The excess water is injected from the filament with air and the filament is cut into tablets with a pill cutter. Preparation of ESI # 's 7 and 8 ESI-7 and 8 are substantially random ethylene / styrene interpolymers prepared using the following catalyst and polymerization procedures Preparation of Catalyst B; (1 H-cyclopentamphenanthrene-2-yl) dimethyl (t-butylamido) -silanetitanium 1,4-diphenylbutadiene 1) Preparation of lithium 1 H-cyclopenta [1] -phenanthrene-2-yl To a 250 ml round bottom flask containing 1.42 g (0.00657 mol) of 1 H-cyclopenta [1] -phenanthrene and 120 ml of benzene, 4.2 ml of 1.60 M of n-BuLi solution in mixed hexanes were added dropwise. The solution was allowed to stir overnight. The lithium salt was isolated by filtration, rinsed twice with 25 ml of benzene and dried in vacuo. The isolated product was 1.426 g (97.7 percent). The 1 H NMR analysis indicated that the predominant isomer was substituted at position 2. 2) Preparation of (1 H-cyclopenta [1] -phenanthrene-2-yl) dimethylchlorosilane To a 500 ml round bottom flask containing 4. 16 g (0.0322 mol) of dimethyldichlorosilane (Me2SiCl2) and 250 ml of tetrahydrofuran (THF), a solution of 1.45 g (0.0064 mol) of lithium 1 H-cyclopenta [1] -phenanthrene-2- was added dropwise. il in THF. The solution was stirred for approximately 16 hours, after which the solvent was removed under reduced pressure, leaving an oily solid which was extracted in toluene, filtered through a diatomaceous earth filter aid (Celite ™), rinsed twice. with toluene and dried under reduced pressure. The isolated product was 1.98 g (99.5 percent). 3) Preparation of (1 H-cyclopenta [1] -phenanthrene-2-yl) dimethyl (t-butylamino) silane To a 500 ml round bottom flask containing 1.98 g (0.0064 mol) of (1 H-) cyclopenta [1] -phenanthrene-2-yl) dimethylchlorosilane and 250 ml of hexane, 2.00 ml (0.0160) of t-butylamine were added. The reaction mixture was allowed to stir for several days, then filtered using a diatomaceous earth filter aid (Celite ™), rinsed twice with hexane. The isolated product was 1.98 g (88.9 percent). 4) Preparation of dilithium (1 H-cyclopenta [1] -phenanthrene-2-yl) dimethyl (t-butylamido) silane To a 250 ml round bottom flask containing 1.03 g (0.0030 mol) of (1 H) -cyclopenta [1] -phenanthrene-2-yl) dimethyl (t-butylamino) silane) and 120 ml of benzene were added dropwise 3.90 ml of a solution of 1.6 M n-BuLi in mixed hexanes. The reaction mixture was stirred for about 16 hours. The product was isolated by filtration, rinsed twice with benzene and dried under reduced pressure. The isolated product was 1.08 g (100 percent).

. Preparation of (1 H-cyclopenta [1] -phenanthrene-2-yl) dimethyl (t-butylamido) silanetitanium dichloride To a 250 ml round bottom flask containing 1.17 g (0.0030 mol) of TiCl 3 »3 THF and approximately 120 ml of TH were added at a rapid drop rate to about 50 ml of a THF solution of 1.08 g of dilithium (1 H-cyclopenta [1] -phenanthrene-2-yl) dimethyl (t-butylamido) silane. The mixture was stirred at about 20 ° C for 1.5 h during which time 0.55 gm (0.002 mol) of solid PbCI2 was added. After stirring for 1.5 h more, the THF was removed in vacuo and the residue was extracted with toluene, filtered and dried under reduced pressure to give an orange solid. The product was 1.31 g (93.5 percent). 6. Preparation of (1 H-cyclopenta [1] -phenanthrene-2-yl) dimethyl (t-butylamido) silanetitanium 1,4-diphenylbutadiene To a mixture of (1 H-cyclopenta [1] -phenanthrene-2-dihydrochloride il) dimethyl (t-butylamido) silanetitanium (3.48 g, 0.0075 mol) and 1,551 gm (0.0075 mol) of 1,4-diphenylbutadiene in about 80 ml of toluene at 70 ° C was added 9.9 ml of a solution 1. 6 M n-BuLi (0.0150 mol). The solution darkened quickly. The temperature was increased to bring the mixture to reflux and the mixture was kept at that temperature for 2 hrs. The mixture was cooled to about -20 ° C and the volatiles were removed under reduced pressure. The residue was mixed in 60 ml of mixed hexanes at about 20 ° C for about 16 hours. The mixture was cooled to about -25 ° C for 1 h. The solids were collected on a porous glass by vacuum filtration and dried under reduced pressure. The dried solid was placed in a piece of fiberglass and the solid was continuously extracted using a soxhlet extractor. After 6 h, a crystalline solid was observed in the boiling vessel. The mixture was cooled to about -20 ° C, isolated by filtration from the cold mixture and dried under reduced pressure to give 1.662 g of a dark crystalline solid. The filtrate was discarded. The solids in the extractor were stirred and the extraction continued with an additional amount of mixed hexanes to give an additional 0.46 gm of the desired product as a dark crystalline solid. Polymerization for ESI 7-8 ESI 7-8 are prepared in a continuous operation cycle reactor (36.8 gal., 139 L). An Ingersoll-Dresser double screw pump provided mixing. The reactor passed the complete liquid at 475 psig (3,275 kPa) with a residence time of approximately 25 minutes. Raw materials and catalyst / cocatalyst streams were fed into the suction of the twin screw pump through Kenics static mixers and injectors. The double screw pump was discharged on a 5.08 cm line that supplied BEM Type Multi-Tube BEM Type 10-68 heat exchangers from Chemineer-Kenics. The tubes of these exchangers contained two twisted ribbons to increase the heat transfer. After leaving the last exchanger, the cycle flow returned through the static injectors and mixers to the suction of the pump. The heat transfer oil was circulated through the outer jacket of the heat exchangers to control the cycle temperature probe located just before the first heat exchanger. The output current of the cycle reactor was drawn between the two exchangers. The density of the solution and the flow of the output stream was measured by Micro Motion. The solvent fed to the reactor is supplied by two different sources. A fresh toluene stream from a 8480-SE Pulsafeeder diaphragm pump with velocities measured by a MicroMovement flowmeter was used to provide instantaneous flow for the reactor seals (20 Ib / ghr (9.1 kg / hr).) The recycled solvent was mixed with unenhanced styrene monomer on the suction side of five 8480-SE Pulsafeeder pumps in parallel These five Pulsafeeder pumps supplied the solvent and styrene to the reactor at 650 psig (4.583 kPa) .The flow of fresh styrene was measured by a MicroMovement flowmeter, and total recycled solvent / styrene flow was measured by a separate MicroMovir flowmeter.Ethylene was supplied to the reactor at 687 psig (4.838 kPa) The ethylene current was measured by a MicroMovement mass flowmeter. a Brooks flowmeter / controller to supply hydrogen in the ethylene stream at the ethylene control valve outlet The ethylene / hydrogen mixture was combined with the solvent / styrene stream at room temperature. The temperature of the total fed stream as it enters the reactor cycle decreases to 2 ° C by means of an exchanger with -10 ° C of glycol in the outer jacket. The preparation of the three catalyst components took place in three separate tanks: the fresh solvent and the concentrated catalyst / cocatalyst premix were added and mixed in their respective operating tanks and fed into the reactor through 680 diaphragm pumps. S-AEN 7 variable speed Pulsafeeder. As previously explained, the system of three component catalysts entered the reactor cycle through an injector and a static mixer on the suction side of the two-screw pump. The feedstock fed stream was also fed into the reactor cycle through an injector and the static mixer downstream of the catalyst injection point but upstream of the two screw pump suction. The polymerization was stopped with the addition of agressive catalyst (water mixed with solvent) in the product line of the reactor after the MicroMovement flowmeter measured the density of the solution. A static mixer in the line provided the dispersion of the agressive catalyst and the additives in the effluent stream of the reactor. This current then entered the post-reactor heaters that provide additional energy for the removal of solvent flow. This flow occurs as the effluent exits the post-reactor heater and the pressure drops from 475 psig (3,275 kPa) below 450 mmHg (60 kPa) of absolute pressure in the reactor pressure control valve.

This fluid polymer enters the first of two hot oil outer jacket devolatilizers. Volatiles flowing from the first devolatilizer were condensed with a glycol outer jacket exchanger, passed through the suction of a vacuum pump and discharged into the solvent and styrene / ethylene separation vessel. The solvent and styrene were removed from the bottom of this container as recycled solvent while the ethylene was removed from the top. The ethylene stream was measured with a MicroMovement mass flowmeter. The measurement of ventilated ethylene plus a calculation of dissolved gases in the solvent / styrene stream was used to calculate the ethylene conversion. The polymer and the remaining solvent separated in the devolatilizer were pumped with a gear pump to a second devolatilizer. The pressure in the second devolatilizer was operated at 5 mm Hg (0.7 kPa) of absolute pressure to flow the remaining solvent. This solvent was condensed in a glycol heat exchanger, pumped through another vacuum pump, and exported to a waste tank for disposal. The dry polymer (<1000 ppm of total volatiles) was pumped with a gear pump to an underwater granulator with a 6-hole nozzle, granulated, dried by centrifugation, and collected in boxes of 1000 Ib. The various catalysts, co-catalysts and process conditions used to prepare the various individual styrene-ethylene interpolymers (ESI # 's 5-8) are summarized in Table 8 and their properties are summarized in Table 9. TABLE 8 * N / A = not available to Catalyst A is dimethyl [N- (1,1-dimethylethyl) -1,1-dimethyl-1 - [(1,2,3,4,5-h) -1,5, 6,7-tetrahydro-3-phenyl-s-indacen-1-yl] silanaminate (2 -) - N] -titanium. b Catalyst B is (1H-cyclopenta [1] phenanthrene-2-yl) dimethyl (t-butylamido) -silanetitanium 1,4-diphenylbutadiene) c Cocatalyst C is tris (pentafluorophenyl) borane, (CAS # 001109-15-5) . d a commercially available methylaluminoxane available from Akzo Nobel as MMAO-3A (CAS # 146905-79-5) TABLE 9 Components of the Polystyrene Mixture PS 1 is a granular polystyrene having a weight average molecular weight, Mw, of about 192,000 and a polydispersity, Mw / Mn of about 2. Examples 5-9: Open Cell Foams with PS / Mixtures ESI, Using Isobutane as Blowing Agent A foaming process comprising a single screw extruder, a mixer and coolants and nozzle was used to make the foam. Isobutane was used as the blowing agent at a charge of 7.5 parts-per-hundred-resin (phr) for Examples 5-8 and 8 weight percent of Example 9 to form polystyrene (PS) and mixtures of PS / ESI TABLE 10 Open Cell Foams with PS / ESI Mixtures, Using Isobutane as a Blowing Agent a experimental procedure described in the same b ASTM D2856 Examples 1 0-1 1: Open Cell Foams with PS / ESI Mixtures, Using CO? As Blowing Agent A foaming process comprising a single screw extruder, a mixer and coolants and nozzle was used to make the foam boards. Carbon dioxide (CO2) was used as the blowing agent at a level of 4.7 phr to foam a mixture of polystyrene with ESI-7. The other additives were: fire retardant = 2.5 phr; Processing auxiliary = 0.2 phr; pigment = 0.15 phr; acid cleaner = 0.2 phr; and linear low density polyethylene = 0.4 phr. TABLE 1 1 Open Cell Foams with PS / ESI Mixtures, Using CQ2 as a Blowing Agent Examples 12: Open Cell Foams with PS / ESI Mixtures, Using Mixtures of HFC-134a / CO? As Blowing Agent A foaming process comprising a single screw extruder, a mixer and coolants and nozzle was used to make foam boards. A mixture of 1.1 phr HFC-134a and 4.23 phr of carbon dioxide (CO2) was used as the blowing agent to foam a polystyrene mixture with ESI. The other additives were: flame retardant = 2.5 phr; Processing auxiliary = 0.2 phr; pigment = 0.15 phr; and acid cleaner = 0.2 phr.

TABLE 12 Open Cell Foams with PS / ESI Mixtures, Using HFC-134a / CO2 as a Blowing Agent to ASTM D2856 The Examples and Comparative Examples of Tables 10, 11 and 12 demonstrate that foams made of polystyrene blends with substantially random ethylene / styrene interpolymers surprisingly have high open cell content (at least 20 vol percent cell ) above a wide range of foaming compositions and temperatures.

Claims (10)

CLAIMS 1. An open cell foam comprising: (A) from 30 to 99.5 weight percent (based on the combined weights of Component A and B) of one or more aromatic alkenyl polymers, and wherein at least one of said alkenyl aromatic polymers has a molecular weight (Mw) of from 100,000 to 500,000; and (B) from 0.5 to 70 percent by weight (based on the 10 combined weights of Component A and B) of one or more substantially random interpolymers having one l2 of 0.1 to 50 g / 10 min, one Mw / Mn of 1.5 to 20; who understands; (1) from 0.5 to 65 percent mol of units of 15 polymer derived from; (a) at least one aromatic vinylidene or vinyl monomer; or (b) at least one vinylidene or vinylidene cycloaliphatic or hindered aliphatic monomer, or (c) a combination of at least one vinylidene or vinyl aromatic monomer and at least one cycloaliphatic or aliphatic vinylidene or vinylidene hindered monomer, and ( 2) from 35 to 99.5 percent mol of 25 polymer units derived from at least one of ethylene or a C3-20 α-olefin, or combination thereof; and (3) from 0 to 20 percent mol of polymer units derived from one or more ethylenically unsaturated polymerizable monomers other than those derived from (1) and (2); and (C) optionally, one or more nucleating agents and (D) optionally one or more other additives; and (E) one or more blowing agents present in a total amount of from 0.5 to 5.0 gram-moles per kilogram (based on the combined weight of Components A and B). 2. The open cell foam according to claim, characterized in that A) in Component (A), said at least one aromatic alkenyl polymer has more than 50 weight percent aromatic monomeric alkenyl units, has a molecular weight ( Mw) of from 120,000 to 350,000 and is presented in an amount of from 50 to 99.5 weight percent (based on the combined weight of Components A and B); B) said substantially random interpolymer, Component (B), has an l2 of 0.3 to 30 g / 10 min and an Mw Mn of 1.8 to 10; it is presented in an amount of from 0.5 to 50 weight percent (based on the combined weight of Components A and B); and comprises (1) from 1 to 50 percent mol of polymer units derived from; (a) said vinylidene or vinyl aromatic monomer represented by the following formula;
1. Ar I R «- c = CH2
2. Wherein R1 is selected from the group of radicals consisting of hydrogen and alkyl radicals containing three carbons or less, and Ar is a phenyl group or a phenyl group substituted with from 1 to 5 substituents selected from the group 15 consisting of halo, C 1 - alkyl, and C 1 - 4 haloalkyl; or (b) said sterically hindered cycloaliphatic or aliphatic vinylidene or vinyl monomer is represented by the following formula; 20 A 'l R' - - e - C (R¿.}. wherein A1 is a sterically bulky cycloaliphatic or aliphatic substituent of up to 20 carbons, R1 is selected from the group of radicals
3. Which consists of alkyl and hydrogen radicals containing from 1 to 4 carbon atoms, preferably hydrogen or methyl; each R2 is independently selected from the group of radicals consisting of alkyl and hydrogen radicals containing from 1 to 4 carbon atoms, preferably hydrogen or methyl; or alternatively R1 and A1 together form an annular system; or c) a combination of a and b 10 (2) from 50 to 85 percent mol of polymer units derived from ethylene or said α-olefin comprising at least one of propylene, 4-methyl-1-pentene, butene-1, hexene-1 or octene-1 or combinations thereof; and 15 (3) said polymerizable ethylenically unsaturated monomers other than those derived from (1) and (2) comprise norbornene, or a C-j.-io alkyl or substituted aryl C6- norbornene.; and (C) said nucleating agent, if present, Component (C), comprises one or more calcium carbonate, talc, clay, silica, barium stearate, calcium stearate, diatomaceous earth, and mixtures of citric acid and sodium bicarbonate; and (D) said additive, if present, Component (D) comprises one or more of inorganic fillers, pigments, antioxidants, acid cleaners, ultraviolet absorbers, flame retardants, processing aids, extrusion aids, permeability modifiers. , antistatic agents, and other thermoplastic polymers (E) said blowing agent, Component (E), is present in a total amount of from 0.2 to
4. 4.0 g-moles / kg (based on the combined weight of Components A and B), and comprises one or more inorganic blowing agents, organic blowing agents, or chemical blowing agents, or combinations thereof. 3. The open cell foam according to claim 1, characterized in that (A) in Component (A), said at least one aromatic alkenyl polymer has more than 70 weight percent aromatic alkenyl monomer units, has a weight molecular weight (Mw) of from 130,000 to 325,000, a molecular weight distribution, (Mw / Mn) of from 2 to 7, and is present in an amount of from 80 to 99.5 weight percent (based on the combined weight of the Components A and B); (B) said substantially random interpolymer, Component (B), has a l2 of 0.5 to 10 g / 10 min and an Mw / Mn of 2 to 5; it is presented in an amount of from 0.5 to 20 weight percent (based on the combined weight of Components A and B); and comprises (1) from 30 to 50 percent mol of polymer units derived from; (a) said vinyl aromatic monomer comprising styrene, α-methyl styrene, Ortho-, meta-, and para-methylstyrene, and the annular halogenated styrenes, or (b) said vinylidene or cycloaliphatic or aliphatic vinyl monomers comprise 5-ethylidene-2-norbornene or 1-vinylcyclohexane, 3-vinylcyclo -hexene and 4-vinylcyclohexene; or (c) a combination of a and b; and (2) from 50 to 70 percent mol of polymer units derived from ethylene, or a A combination of ethylene and said α-olefin, comprising ethylene, or ethylene and at least one of propylene, 4-methyl-1-penten, butene-1, hexene-1 or octene-1; and (3) said polymerizable monomers 25 ethylenically unsaturated agents other than those derived from (1) and (2) is norbornene; and (C) said nucleating agent, if present, Component (C), comprises one or more of talc, silica, and mixtures of citric acid and sodium bicarbonate; (D) said additive, if present, Component (D) comprises one or more of natural gas carbon black, titanium dioxide, graphite, flame retardants, and other thermoplastic polymers; and 10 (E) said blowing agent, Component (E), is present in a total amount of from 0.5 to 3.0 g-moles / kg (based on the combined weight of Components A and B), and comprises one or more of nitrogen, sulfur hexafluoride (SF6), argon, dioxide 15 carbon, water, air and helium, methane, ethane, propane, n-butane, isobutane, n-pentane, isopentane, neopentane, cyclopentane, methanol, ethanol, n-propanol, and isopropanol, methyl fluoride, perfluoromethane, fluoride ethyl,), 1,1-difluoroethane (HFC-152a), fluoroethane (HFC-161), 20,1,1-Trifluoroethane (HFC-143a), 1,1,1,2-tetrafluoroethane (HFC-134a), pentafluoroethane (HFC-125), 1,1,2,2-tetrafluoroethane (HFC-134), 1,1,1,3,3-pentafluoropropane, difluoromethane (HFC-32), perfluoroethane, 2,2-difluoropropane, 1,1,1-trifluoropropane, perfluopropane, 25 dichloropropane, difluoropropane, perfluorobutane, perfluorocyclobutane, methyl chloride, methylene chloride, ethyl chloride, 1,1-trichloroethane, 1,1-dichloro-1-fluoroethane (HCFC-141b), 1-chloro- 1,1-difluoroethane (HCFC-142b), chlorodifluoromethane (HCFC-22), 1,1-dichloro-2,2,2-trifluoroethane (HCFC-123) and 1-chloro-1,2,2,2-tetrafluoroethane (HCFC-124), trichloromonofluoromethane (CFC-11), dichlorodifluoromethane (CFC-12), trichlorotrifluoroethane (CFC-113), dichlorotetrafluoroethane (CFC-114), chlorheptafluoropropane, dichlorohexafluoropropane, azodicarbonamide, azodiisobutyronitrile, • benzenesulfonhydrazide, 4,4-oxybenzenesulfonyl-semicarbazide, p-toluene sulfonyl semi-carbazide, barium azodicarboxylate, N, N'-dimethyl-N, N'-dinitroso-terephthalamide, trihydrazino triazine and mixtures of citric acid and bicarbonate of sodium. The open cell foam according to claim 3, characterized in that said alkenyl aromatic polymer, Component (A), is polystyrene, said substantially random interpolymer, Component (B), is an ethylene / styrene interpolymer, and the blowing agent , Component (E), is one or more of carbon dioxide, ethane, propane, n-butane, isobutane, n-pentane, isopentane, neopentane, cyclopentane, ethanol, 1,1-difluoroethane (HFC-152a), 1, 1,2,2-tetrafluoroethane (HFC-134a), 1,1,2,2-tetrafluoroethane (HFC-134), ethyl chloride, 1-chloro-1,1-difluoroethane (HCFC-142b) or chlorodifluoromethane (HCFC- 22).
5. 5. The open cell foam according to claim 3, characterized in that said alkenyl aromatic polymer, Component (A), is polystyrene, in said substantially random interpolymer, Component B1 (a) is styrene; and Component B2 is ethylene and at least one of propylene, 4-methyl-1-pentene, butene-1, hexene-1 or octene-1, and the blowing agent, Component (E), is one or more of carbon dioxide , ethane, propane, n-butane, isobutane, n-pentane, isopentane, neopentane, cyclopentane, ethanol, 1,1-difluoroethane (HFC-152a), 1,1, 1,2-tetrafluoroethane (HFC-134a), 1 , 1,2,2-tetrafluoroethane (HFC-134), ethyl chloride, 1-chloro-1,1-difluoroethane (HCFC-142b) or chlorodifluoromethane (HCFC-22).
6. 6. The foam according to claim 1, which has a density of 10 to 200 kilograms per cubic meter (kg / m3) and a cell size of 5 to 2000 microns.
7. 7. The open cell foam according to claim 1, having a density of from 15 to 100 kg / m3 and a cell size of from 20 to 1000 microns. The open cell foam according to claim 1, characterized in that the alkenyl aromatic polymer material comprises more than 70 weight percent aromatic alkenyl monomer units, and the foam has a density of from 10 to 200 kilograms per meter cubic (kg / m3) and a cell size of 5 to 2000 microns. 9. The open cell foam according to claim 1, characterized in that the alkenyl aromatic polymer material comprises more than 70 weight percent aromatic alkenyl monomer units, and the foam has a density of from 15 to 100 kg / m3 and a cell size of 20 to 1000 microns. 10. A process for making an open cell foam, such process comprises; (I) forming a fused polymer material comprising: (A) from 30 to 99.5 weight percent (based on the combined weights of Component A and B) of one or more aromatic alkenyl polymers, and wherein at least one of said aromatic alkenyl polymers has a molecular weight (Mw) of from 100,000 to 500,000; and (B) from 0.5 to 70 weight percent (based on the combined weight of Component A and B) of one or more substantially random interpolymers having an I2 of 0.1 to 50 g / 10 min, an Mw / Mn of 1 .5 to 20; who understands; (1) from 0.5 to 65 percent mol of polymer units derived from; to. at least one vinylidene or vinyl aromatic monomer; or b. at least one vinylidene or vinyl cycloaliphatic or hindered aliphatic monomer, or c. a combination of at least one aromatic vinylidene or vinyl monomer and at least one cycloaliphatic or aliphatic hindered vinylidene or vinyl monomer, and (2) from 35 to 99.5 mol percent of polymer units derived from at least one ethylene or a C3-2o α-olefin, or combination thereof; and (3) from 0 to 20 percent mol of polymer units derived from one or more ethylenically unsaturated polymerizable monomers other than those derived from (1) and (2); and (C) optionally, one or more nucleating agents and (D) optionally one or more other additives; and (II) incorporating into said fused polymer material at an elevated pressure to form a foamable gel (E) one or more blowing agents present in a total amount of from 0.5 to 5.0 gram-moles per kilogram (based on the combined weight of Components A and B). (III) cooling said foamable gel to an optimum foaming temperature; and (IV) extrude the Stage III gel through a nozzle to a lower pressure region to form a foam. eleven . The process according to claim 10, characterized in that (A) in the Component (A), said at least one aromatic alkenyl polymer has more than 50 weight percent aromatic alkenyl monomer units, has a molecular weight (Mw) of from - 120,000 to 350,000 and is presented in an amount of from 50 to 99.5 weight percent (based on the combined weight of Components A and B); (B) said substantially random interpolymer, Component (B), has an l2 of 0.3 to 30 g / 10 min and an Mw / Mn of 1.8 to 10; it is presented in an amount of from 0.5 to 50 weight percent (based on the combined weight of Components A and B); and comprises (1) from 15 to 50 percent mol of polymer units derived from; (a) said vinylidene or vinyl aromatic monomer represented by the following formula; Ar í Rl ___ C - CH2 wherein R1 is selected from the group of radicals consisting of hydrogen and alkyl radicals containing three carbons or less, and Ar is a phenyl group or a phenyl group substituted with from 1 to 5 substituents selected from the group consisting of halo, alkyl C1-4, and C1-4 haloalkyl; or (c) said sterically hindered cycloaliphatic or aliphatic vinylidene or vinyl monomer is represented by the following formula; A 'I Ri-c-C (^) 10 wherein A1 is a sterically bulky cycloaliphatic or aliphatic substituent of up to 20 carbons, R1 is selected from the group of radicals consisting of alkyl and hydrogen radicals 15 containing from 1 to 4 carbon atoms, preferably hydrogen or methyl; each R2 is independently selected from the group of radicals consisting of alkyl and hydrogen radicals containing from 1 to 4 atoms 20 carbon, preferably hydrogen or methyl; or alternatively R1 and A1 together form an annular system; or (c) a combination of a and b (2) from 50 to 85 percent mol 25 polymer units derived from ethylene or said α-olefin comprising at least one of propylene, 4-methyl-1-penten, butene-1, hexene-1 or octene-1 or combinations thereof; and (3) said polymerizable ethylenically unsaturated monomers other than those derived from (1) and (2) comprise norbornene, or a C 1-10 alkyl or substituted aryl C 6-10 norbornene; and (C) said nucleating agent, if present, Component (C), comprises one or more calcium carbonate, talc, clay, silica, calcium stearate, barium stearate, diatomaceous earth, and mixtures of citric acid and sodium bicarbonate; and (D) said additive, if present, Component (D) 15 comprises one or more inorganic fillers, pigments, antioxidants, acid cleaners, ultraviolet absorbers, flame retardants, processing aids, extrusion aids, permeability modifiers, agents 20 antistatics, and other thermoplastic polymers (E) said blowing agent, Component (E), is present in a total amount of from 0.2 to 4.0 g-moles / kg (based on the combined weight of Components A and B), and understands 25 one or more inorganic blowing agents, organic blowing agents, or chemical blowing agents, or combination thereof. The process according to claim 10, characterized in that: (A) in the Component (A), said at least one aromatic alkenyl polymer has more than 70 weight percent aromatic monomeric alkenyl units, has a molecular weight ( Mw) of from 130,000 to 325,000, a molecular weight distribution, (Mw / Mn) of from 2 to 7, and is present in an amount of from 80 to 99.5 weight percent (based on the combined weight of Components A and B); (B) said substantially random interpolymer, Component (B), has an I of 0.5 to 10 g / 10 min and an Mw Mn of 2 to 5; it is presented in an amount of from 0.5 to 20 weight percent (based on the combined weight of Components A and B); and comprises (1) from 30 to 50 percent mol of polymer units derived from; (a) said vinyl aromatic monomer comprising styrene, a-methyl, ortho-, meta-, and para-methylstyrene styrene, and the annular halogenated styrenes, or (b) said vinylidene or cycloaliphatic or aliphatic vinyl monomers comprising: - ethylidene-2-norbornene or 1-vinylcyclohexene, 3-vinylcyclohexene and 4-vinylcyclohexene; or (c) a combination of a and b; and (2) from 50 to 70 percent mol of polymer units derived from ethylene, or ethylene and said α-olefin, comprising ethylene, or ethylene and at least one propylene, 4-methyl-1-10 pentene, butene-1, hexene-1 or octene-1; and (3) said polymerizable ethylenically unsaturated monomers other than those derived from (1) and (2) is norbornene; and (C) said nucleating agent, if present, Component (C), comprises one or more of talc, silica, and mixtures of citric acid and sodium bicarbonate; (D) said additive, if present, Component (D) comprises one or more of gas carbon black 20 natural, titanium dioxide, graphite, flame retardants, and other thermoplastic polymers; and (E) said blowing agent, Component (E), is present in a total amount of from 0.5 to 3.0 g-moles / kg (based on the combined weight of 25 Components A and B), and comprises one or more of nitrogen, sulfur hexafluoride (SF6), argon, carbon dioxide, water, air and helium, methane, ethane, propane, n-butane, isobutane, n-pentane, isopentane, neopentane, cyclopentane, methanol, ethanol, n-propanol, and isopropanol, methyl fluoride, perfluoromethane, ethyl fluoride,), 1,1-difluoroethane (HFC-152a), fluoroethane (HFC-161), 1,1 , 1-trifluoroethane (HFC-143a), 1,1, 1,2-tetrafluoroethane (HFC-134a), 1,1,2,2-tetrafluoroethane (HFC-134), 1,1,1,3,3-pentafluoropropane , pentafluoroethane (HFC-10 125), difluoromethane (HFC-32), perfluoroethane, 2,2-difluoropropane, 1,1-trifluoropropane, perfluoropropane, dichloropropane, difluoropropane, perfluorobutane, perfluorocyclobutane, methyl chloride, methylene chloride, ethyl chloride, 1,1,1-trichloroethane, 1,1-dichloro-15 1-fluoroethane (HCFC-141b), 1-chloro-1,1-difluoroethane (HCFC-142b), chlorodifluoromethane (HCFC-22) ), 1,1-dichloro-2,2,2-trifluoroethane (HCFC-123) and 1-chloro-1, 2,2,2- tetrafluoroethane (HCFC-124), trichloromonofluoromethane (CFC-11), dichlorodifluoromethane (CFC-12), trichloro¬ 20 trifluoroethane (CFC-113), dichlorotetrafluoroethane (CFC-114), chlorheptafluoropropane, dichlorohexafluoropropane, azodicarbonamide, azodiisobutyronitrile, benzenesulfonhydrazide, 4,4-oxybenzenesulfonyl-semicarbazide, p-toluene sulfonyl semi-carbazide, Barium azodicarboxylate, N, N'-dimethyl-N, N'-dinitroso-terephthalamide, trihydrazino triazine and mixtures of citric acid and sodium bicarbonate. The process according to claim 12, characterized in that said Component (A), is polystyrene, said substantially random interpolymer, Component (B), is an ethylene / styrene interpolymer, and the blowing agent, Component (E), is one or more carbon dioxide, ethane, propane, n-butane, isobutane, n-pentane, isopentane, neopentane, cyclopentane, ethanol, 1,1-difluoroethane (HFC-152a), 1,1,1,2-tetrafluoroethane ( HFC-134a), 1,1,2,2-tetrafluoroethane (HFC-134), ethyl chloride, 1-chloro-1,1-difluoroethane (HCFC-142b) or chlorodifluoromethane (HCFC-22). The process according to claim 12, characterized in that said aromatic alkenyl polymer, Component (A), is polystyrene, in said substantially random interpolymer, Component B1 (a) is styrene; and Component B2 is ethylene and at least one of propylene, 4-methyl-1-pentene, butene-1, hexene-1 or octene-1, and the blowing agent, Component (E), is one or more of carbon dioxide , ethane, propane, n-butane, isobutane, n-pentane, isopentane, neopentane, cyclopentane, ethanol, 1,1-difluoroethane (HFC-152a), 1,1,1,2-tetrafluoroethane (HFC-134a), 1 , 1,2,2-tetrafluoroethane (HFC-134), ethyl chloride, 1-chloro-1,1-difluoroethane (HCFC-142b) or chlorodifluoromethane (HCFC-22). 15. The process according to claim 10, characterized in that the foam has a density of from 10 to 200 kilograms per cubic meter (kg / m3) and a cell size of 5 to 2000 microns. The process according to claim 10, characterized in that the foam has a density of from 15 to 100 kg / m3 and a cell size of from 20 to 1000 microns. The process according to claim 10, characterized in that Component A comprises more than 70 weight percent of alkenyl aromatic monomer units, and the foam has a density of from 10 to 200 kilograms per cubic meter (kg / m3) and a cell size of 5 to 2000 microns. The process according to claim 10, characterized in that Component A comprises more than 70 weight percent aromatic monomeric alkenyl units, and the foam has a density of from 15 to 100 kg / m3 and a cell size of 20 to 1000 microns. The process according to claim 10, characterized in that in step (IV) said foamable gel is extruded through a multi-orifice nozzle to a lower pressure region such that contact between the adjacent streams of the fused extrudate occurs during the foaming process and the contact surfaces adhere to each other with sufficient adhesion to result in a unitary foam structure to form a coalesced filament foam. The process according to claim 10, characterized in that in step (IV) the foamable gel is: 1) extruded in a conservation zone maintained at a temperature and pressure that does not allow the gel to be foamed, the conservation zone having an outlet nozzle defining an orifice opening in a lower pressure zone to which the gel foams, and an opening step that closes the nozzle orifice; 2) periodically open the step; 3) apply substantially concurrently mechanical pressure by a movable piston in the gel to expel it from the conservation zone through the nozzle orifice towards the lower pressure zone, at a speed greater than that, at which the substantial foaming at the nozzle orifice occurs and less than that, to which irregularities in cross-sectional area or shape occur; and 4) allowing the ejected gel to expand without limitation in at least one dimension to produce the foam structure. twenty-one . The process according to claim 10, characterized in that said optimum foaming temperature is between 1 10 ° C and 135 ° C. 22. The open cell foam according to claim 1, characterized in that they have a water absorption value of from 5 to 25 g / g of foam.