MXPA01005578A - Foams having increased heat distortion temperature made from blends of alkenyl aromatic polymers and alpha-olefin/vinyl or vinylidene aromatic and/or sterically hindered aliphatic or cycloaliphatic vinyl or vinylidene interpolymers - Google Patents

Abstract

The present invention pertains to improved alkenyl aromatic polymer foams (and processes for their preparation) having increased heat distortion temperature and improved dimensional stability while maintaining good tensile/tear, creep and environmental dimensional change properties. The closed cell low density alkenyl aromatic polymer foams exhibit increased heat distortion temperature, when substantially random interpolymers of 21 to 65 mol percent styrene are blended in. When these same alkenyl aromatic polymer foams are made without these interpolymers, the heat distortion temperature is not improved.

Description

FOAMS THAT HAVE TEMPERATURE OF DISTORTION BY INCREASED HEAT FORMED OF MIXTURES OF POLYMERS AROMATICS OF ALKINYL AND INTERPOLYMERS OF ALPHA- OLEFINE / VINYL OR VINYLIDENE AROMATIC AND / OR VINYL OR VINYLIDENE ALIPHATIC OR CICLOALIATIC, ESTERICALLY HIDDEN This invention describes a method for increasing the heat distortion temperature of alkenyl aromatic foams by mixing polymers comprising (A) aromatic alkenyl polymers and (B) substantially random interpolymers of vinylidene or vinylidene aliphatic or cycloaliphatic, aromatic and / or aesthetically hidden vinyl or vinylidene. Suitable alkenyl aromatic polymers include alkenyl aromatic homopolymers and copolymers of alkenyl aromatics and ethylenically unsaturated copolymerizable comonomers. A preferred alkenyl aromatic polymer is polystyrene. The substantially random interpolymers comprise polymeric units derived from ethylene and / or one or more α-olefin monomers with specific amounts of one or more vinyl aromatic vinyl or vinylidene monomers and / or aliphatic or cycloaliphatic, sterically hidden vinyl or vinylidene monomers. A preferred substantially random interpolymer is an ethylene / styrene interpolymer. The incorporation of the substantially random interpolymer in the mixture with aromatic alkenyl polymers results in an increase in the heat distortion temperature of the resulting foam.

Foams formed by aromatic alkenyl polymers such as polystyrene, usually exhibit changes in dimension as the temperature increases significantly above room temperature. The consideration of the heat distortion temperature of alkenyl aromatic foam is very important when it is being used in a relatively high temperature application close to the service temperature limit of the foam (approximately 73.88 ° C for polystyrene foam If the heat distortion temperature of a foam is too low, it can be subject to disfigurement and / or rupture.The stresses established during the manufacture of the foam dissipate as the temperature rises and the linear dimensions of the Foams are increased or reduced (depending on the orientation of the foam and whether the gas pressure of the cell is above or below the ambient pressure) The temperature at which the significant constriction or expansion occurs depends on the transition temperature to polymer matrix glass, which can be reduced due to plasticization by the blower gage resid ual and other additives that are soluble in the polymer. These effects may limit the upper service temperature of the foam. A measurement of the upper service temperature, and a test to determine the dimensional stability of the foam as a function of temperature, is the Heat Distortion Temperature Test (ASTM D2126-94) which measures the linear change in three dimensions of a foam when exposed to different temperatures. A common elevated temperature application for foaming Alkenyl aromatics is found in the roof. In the roofing, the foam is typically used below a roofing membrane, which is dark and rubber-like, and can reach service temperature limits when it is below a membrane exposed to direct sunlight on the roof. summer months. If the foam is distorted, the membrane and foam can be separated to form empty bags, leaving the membrane with less mechanical support on its lower surface. The lack of support on the lower surface makes the membrane more susceptible to rupture, which results in leakage of water into the roof. The Patents of E.U. Nos. 5,41 1, 687; 5,434, 195; 5,557,896; 5,693,687; 5,784,845; and 5, 824,710, describe open cell foams (ie containing 30 percent or more open cells) as a means to obtain high heat distortion temperatures. However, the high open cell content of these foams can result in lower thermal insulation performance (due to the rapid loss of insulating blowing agent) as well as increased water absorption, both of which are undesirable. In this way it would be desirable to have a closed cell alkenyl aromatic foam with increased heat distortion temperature and improved dimensional stability which also shows good vapor resistance, water resistance, and mechanical strength. The uses of such foam would increase insulation in construction and building, as well as in the preparation of foam film labels for bottles and other containers, where stability High dimensional of such labels would minimize any constriction or distortion of the label when the label bottle cools down after manufacture. Surprisingly it has been found that foams made from blends of alkenyl aromatic polymers and the specific amounts and types of substantially random interpolymers show increased heat distortion temperatures relative to analogous alkenyl aromatic polymer foams made without substantially random interpolymers even when the foams are predominantly closed cells (ie, the open cell content of percent in volume or less). In addition, compared to the corresponding foams made without the interpolymers, the foams of the present invention show better or similar performance in the slip tests (such as DIN 18164 and ASTM 3575 suffix BB) and environmental dimensional change tests (ASTM C578- 83), as well as improved tensile strength / elongation (ASTM D614-91) and tear / elongation resistance (ASTM D412-87). The present invention pertains to alkenyl aromatic polymer foams (and processes for their preparation) having increased heat distortion temperature and improved dimensional stability while maintaining excellent tensile / tear, sliding and environmental dimensional change properties. The foams comprise: (A) from 80 to 98 weight percent (based on the combined weight of Components A and B) of one or more polymers alkenyl aromatics and wherein at least one of said alkenyl aromatic polymers has a molecular weight (Mw) of from 1,000,000 to 500,000; and (B) from 2 to 20 weight percent (based on the combined weight of Components A and B) of one or more substantially random interpolymers having one l2, from 0.1 to 1000 g / 10 min, and one Mw / Mn, from 1.5 to 20; comprising (1) from 21 to 65 mole percent of the polymer units derived from: (a) at least one vinylidene or vinylidene aromatic monomer, or (b) at least one aliphatic or cycloaliphatic vinylidene or hidden vinylidene monomer , or (c) a combination of at least one vinyl or vinylidene aromatic monomer and at least one aliphatic or cycloaliphatic vinylidene or hidden cycloaliphatic monomer, and (2) from 35 to 79 mole percent of polymer units derived from at least one of ethylene and / or C3-2 o-olefin; and (3) from 0 to 20 mole percent of polymer units derived from one or more polymerizable ethylenically unsaturated monomers other than those derivatives of (1) and (2); Y (C) optionally, one or more nucleating agents; and (D) optionally, one more different additives; and (E) one or more blowing agents present in a total amount of 0.2 to 5.0 grams-moles per kilogram (based on the combined weight of Components A and B); wherein the heat distortion temperature of said foam is increased by 2 ° C or more relative to a corresponding foam without the substantially random interpolymer. In a preferred embodiment the foam having increased heat distortion temperature and dimensional stability is also a closed cell foam (ie, with 20 vol percent or less of open cells.) This combination allows the manufacture of alkenyl aromatic polymer foams. of low density heat distortion temperature increased, when substantially random interpolymers of 21 to 65 mole percent of styrene are used.When these same alkenyl aromatic polymer foams are formed without these interpolymers, the heat distortion temperature does not In addition, it has unexpectedly been found that the tensile and tear properties of the foam can be improved by using substantially random interpolymers Definitions All references herein to the elements or metals belonging to a certain Group relate to the Periodic Table of the Elements published and copyrighted by CRC Press Inc., 1989. Also any reference in the Group or Groups should be to the Group or Groups as reflected in this Periodic Table of the Elements using the IUPAC system for the numbering groups. Any numerical value described herein, includes all values from the value below 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, if it is stated that the amount of a component or a value of a process variable such as, for example, temperature, pressure and time, for example, from 1 to 90, preferably from 20 to 80, more preferably from 30 to 70, it is intended that values such as 1 5 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 that can be 0.0001, 0.001, 0.01, or 0.1 is considered appropriate. These are only examples of what is specifically intended and all possible combinations of the numerical values between the lower value and the upper 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, aliphatic substituted with aryl, cycloaliphatic substituted with aryl, aromatic substituted with aliphatic or cycloaliphatic substituted with aliphatic 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 "copolymer" as used herein means a polymer wherein at least two different monomers are polymerized to form the copolymer. The term "interpolymer" is used herein to denote a polymer wherein at least two different monomers are polymerized to form the interpolymer. This includes copolymers, terpolymers, etc. The term "heat distortion temperature" is used herein to indicate an increase in the heat distortion temperature of a foam of the present invention of 2 ° C or more, preferably 3 ° C or more, and more preferably. ° C to more, relative to a corresponding foam without the substantially random interpolymer. The invention especially covers foams comprising mixtures of one or more alkenyl aromatic homopolymers or copolymers of alkenyl aromatic monomers, and / or copolymers of aromatic alkenyl monomers with one or more copolymerizable ethylenically unsaturated comonomers (other than ethylene or α-olefins). C3-C? 2 linear) with at least one substantially random interpolymer. The foams of this invention have increased heat distortion temperatures relative to corresponding foams of similar density made without the substantially random interpolymer. The aromatic alkenyl polymer material may also include minor proportions of aromatic polymers without alkenyl. He Alkenyl aromatic polymer material may 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 alkenyl homopolymers and aromatic copolymers, or mixtures of any of the foregoing with an aromatic polymer without alkenyl. Despite 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 aromatic alkenyl polymer material is entirely comprised of alkenyl aromatic monomer units. Suitable alkenyl aromatic polymers include homopolymers and copolymers derived from alkenyl aromatics such as styrene, alphamethylstyrene, ethylstyrene, vinylbenzene, vinyl toluene, chlorostyrene, and bromostyrene. A preferred alkenyl aromatic polymer is polystyrene. The aromatic alkenyl polymeric material may also include commercial H IPS (high impact polystyrene). Minor amounts of monoethylenically unsaturated compounds such as C 2-6 alkyl acids and esters, ionomeric derivatives and C 4-6 dienes can be copolymerized with alkenyl aromatic compounds. 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 polymeric units derived from ethylene and one or more α-olefin monomers with one or more vinyl or vinylidene aromatic monomers and / or aliphatic or cycloaliphatic vinylidene or vinylidene monomers) as used herein, it means that the distribution of the monomers of said interpolymer can be described by the Bernoulli statistical model or by a first and second order Markovian statistical model, as described by JC. Randall in POLYMER SEQUENCE DETERMINATION. Carbon-13 NMR Method. Academic Pres New York, 1977, 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 NMR spectrum of the "13" carbon of the substantially random interpolymer the peak areas corresponding to the methylene and the methylene chain moieties representing either bivalent radical meso sequences or racemic bivalent radical sequences can not exceed 75. percent of the total peak area of the main chain methine and methylene carbons The interpolymers used to prepare the foams of the present invention include substantially random interpolymers prepared by polymerizing) ethylene and / or one or more α-olefin monomers and ii) one or more vinyl or vinylidene aromatic monomers and / or one or more aliphatic or hidden cycloaliphatic vinyl or vinylidene monomers, and optionally iii) other polymerizable ethylenically unsaturated monomers. Suitable α-olefins include, for example, α-olefins containing from 3 to 20, preferably from 3 to 12, more preferably from 3 to 8 carbon atoms. Ethylene, propylene, butene-1,4-methyl-1-pentene, hexene-1 or octene-1 or ethylene are particularly suitable in combination with one or more of propylene, butene-1,4-methyl-1-pentene, hexene-1 or octene-1. These α-olefins do not contain an aromatic portion. Other optional polymerizable ethylenically unsaturated monomers include norbornene and norbornenes substituted with C6 aryl. 10 or alkyl of with an illustrative interpolymer being ethylene / styrene / norbornene. Suitable vinyl or vinylidene aromatic monomers that can be used to prepare the interpolymers include, for example, those represented by the following formula: Ar I (CHa) "R '- C = Q (R2H wherein R1 is selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms, preferably hydrogen or methyl; each R2 is independently selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms, preferably hydrogen or methylene; Ar is a phenyl group or a phenyl group substituted with from 1 to 5 substitutes selected from the group consisting of halo, C? -4 alquilo alkyl, and C?. Halo haloalkyl; and n has a value from zero to 4, preferably from zero to 2, more preferably zero. Illustrative vinyl aromatic monomers include styrene, vinyl toluene, α-methylstyrene, t-butyl styrene, chlorostyrene, including all isomers of these compounds, and the like. Particularly suitable monomers include styrene and derivatives substituted with halogen or lower alkyl thereof. Preferred monomers include styrene, α-methylstyrene, substituted phenyl ring derivatives or lower alkyl (C?-C4) styrene, such as, for example, ortho-, meta- and para-methylstyrene, halogenated ring styrenes, para-vinyl toluene or mixtures thereof, and the like. A most preferred aromatic vinyl monomer is styrene. By the term "aesthetically concealed aliphatic or cycloaliphatic vinylidene or vinylidene compounds" means the addition of polymerizable vinyl or vinylidene monomers corresponding to the formula: A »Ri - C = C (R *) 2 wherein A1 is a sterically bulky aliphatic or cycloaliphatic substitute of up to 20 carbons, R1 is selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms, preferably hydrogen or methyl; each R2 independently is selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms, preferably hydrogen or methyl; or alternatively R1 and A1 together form a ring system. Preferred vinylidene, vinylidene, cycloaliphatic or cycloaliphatic compounds in which one of the carbon atoms bearing the ethylenic unsaturation is a tertiary or quaternary substitute. Examples of such substitutes include cyclic aliphatic groups such as cyclohexyl, cyclohexenyl, cyclooctenyl or aryl-substituted or ring-alkyl derivatives thereof, tert-butyl and norbornyl, and the like. The most preferred vinylidene, aliphatic or cycloaliphatic or vinylidene compounds are various isomeric vinyl ring substituted derivatives of cyclohexene and substituted cyclohexenes and 5-ethylidene-2-norbornene. 1-, 3- and 4-vinylcyclohexane are especially suitable. Simple linear 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 are not examples of sterically hidden vinylidene, aliphatic or cycloaliphatic vinylidene compounds. Substantially random interpolymers include the pseudo-random interpolymers as described in EP-A-0,416,815 by James C. Stevens et al. , and U.S. Patent No. 5,703, 187 by Francis J. Timmers, both of which are incorporated herein by reference in their entirety. Substantially random interpolymers are prepared by polymerizing a mixture of polymerizable monomers in the presence of one or more constrained geometric metallocenes or catalysts in combination with several cocatalysts. The conditions Preferred operating conditions for such polymerization reactions are pressures from atmospheric 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 the polymerization of free radicals. Examples of suitable catalysts and methods for the preparation of substantially random interpolymers are described in the U.S. Application Serial No. 702,475 filed May 20, 1991 (EP-A-514,828); as well as U.S. Patent Nos .: 5,055,438; 5,057,475; 5,096,867; 5,064,802; 5, 132,380; 5, 1 89, 192; 5,321, 106; 5,347,024; 5,350,723; 5,374,696; 5,399,635; 5,470,993; 5,703, 187; and 5,721, 185. The substantially random α-olefin / vinyl aromatic interpolymers may also be prepared by the methods described in JP 07/278230 which employ the compounds shown in the general formula ? ? / R3 M wherein Cp1 and Cp2 are cyclopentadienyl groups, indenyl groups, fluorenyl groups, or substitutes thereof, independently of one another; R1 and R2 they are hydrogen atoms, halogen atoms-- hydrocarbon groups with carbon numbers of 1 -12, ilo groups or aryloxyl groups, independently of one another; M is a net! of group IV, preferably Zr or Hf, more preferably Zr; "is an alkylene group or silanodiyl group used to degrade Cp1 and '2). The aromatic interpolymers? Substantially randomized α-olefin / vinyl can also be prepared by the methods described by John G. Bradfute ei. (W.R. Grace &Co.) in WO 95/32095; by R. B. Pannell (Exxon Ce nical Patents, Inc.) in WO 94/00500; and in Plastics Technology, p. 25 «September 1992). Substantially randomized terpolymers comprising at least one a-olefin / vinyl aromatic / vinyl aromatic / α-olefin tetrades described in US Application No. 08 / 708,869 filed on September 4, 1996, are also suitable. WO 98/09999 both by Francis J. Timmers et al. These interpolymers contain additional signals in their carbon-13 NMR spectrum with intensities greater than three times the peak-to-peak interference. These signals appear on the chemical change scale 43.70 - 44.25 ppm and 38.0 - 38.5 ppm. Specifically, the main peaks were observed 44.1, 43.9 and 38.2 ppm. A proton test experiment by NMR indicates that the signals in the region of chemical changes of 43.70 - 44.25 ppm are methine carbons and the signals in the region of 38.0 - 38.5 ppm are methylene carbons. It is thought that these new signals are due to sequences involving two inserts of aromatic monomers from viniio from head to tail preceded and followed by at least one α-olefin insert. For example, an ethylene / styrene / styrene / ethylene tetrad wherein the styrene monomer insertions of said tetrads occur exclusively in a 1, 2 (head-to-tail) form. It will be understood by one skilled in the art that for such tetrads involving a vinyl aromatic monomer other than styrene and an a-olefin other than ethylene the aromatic monomer of the ethylene / vinyl tetrad / aromatic vinyl / ethylene monomer will give rise to NMR peaks of carbon-1 3 similar but with slightly different chemical changes. These interpolymers can be prepared by carrying out the polymerization at a temperature of -30 ° C to 250 ° C in the presence of catalysts such as those represented by the formula wherein: each Cp is independently, each time they occur, a substituted cyclopentadienyl group joined-p 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 time H, hydrocarbyl, siiahydrocarbyl or hydrocarbylsilyl is present, containing up to about 30 preferably from 1 to 20, more preferably from 1 to 10 carbons or silicon atoms; each R 'each time it occurs, is independently H, halo, hydrocarbyl, hydrocarbyloxy, silahydrocarbyl, hydrocarbylsilyl containing up to about 30, preferably from 1 to 20, more preferably from 1 to 10 carbon atoms or silicon, or two R 'groups together may be a C 1, substituted hydrocarbyl 1,3-butanediene or, m is 1 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, each time it occurs, is independently H, hydrocarbyl, silahydrocarbyl, or hydrocarbylsilyl, containing up to about 30, preferably from 1 to 20, more preferably from 1 to 10 carbon atoms or silicon or two R groups together they form a divalent derivative of such a group. Preferably, R independently each time it is (including all isomers where appropriate) hydrogen, methyl, ethyl, propyl, buryl, pentyl, hexyl, benzyl, phenyl or silyl or (when appropriate) two R groups are linked together forming a fused ring system such as indenyl, fluorenyl, tetrahydroindenyl, tetrahydrofluorenyl or octahydrofluorenyl. Particularly preferred catalysts include, for example, racemic (dimethylsilanediyl) bis (2-methyl-4-phenylindenyl) zirconium dichloride, 1,4-diphenyl-1,3-butadiene (dimethylsilanediyl) -bis- (2-methyl) Racemic 4-phenyl-indenyl) -circonium, dialkyl of d.4 of racemic (dimethylsilanediyl) -b- (2-methyl-4-phenylindenyl) -zirconium, di-alkoxide of C ^ of racemic (dimethylsilanediyl) -bis- (2-methyl-4-phenylindenyl), or any combination thereof and the like. It is also possible to use the following constrained geometric 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-γ) -1-indenyl) (tert-butylamido) dimethylsilane titanium; and dimethyl (3-iso-propyl) (1, 2,3,4, 5-γ) -1-indenyl) (tert-butyl amido) dimethylsilane titanium, or any combination thereof and the like. Additional preparative methods for the interpolymers used in the present invention have been described in the literature. Longo and Grasi (Makromol Chem .. Volume 191, pages 2387 to 2396 [1990] and D'Anniello et al (Journal of Applied Polymer Science, volume 58, pages 1 701 -1706 [1995]) report the use of a system catalyst based on methylalumoxane (MAO) and cyclopentadienyltitanium trichloride (CpTiCl3) to prepare an ethylene-styrene copolymer Xu and Lin (Polvmer Preprints, Am. Chem. Soc. Div. Polvm. Chem.) Volume 35, pages 686, 687 [1 994]) have reported copolymerization using a MgCl2 / TiCl / NdCI3 / AI (iBu) 3 catalyst to give random copolymers of styrene and propylene. Lu et al. (Journal of Applied Polvmer Science, Volume 53, pages 1453 to 1460 [1994]) have described the copolymerization of ethylene and styrene using a TiCl 4 / NdCl 3 / MgCl AI (Et) 3 catalyst. Sernetz and Mulhaupt, (Macromol., Chem. Phys., V. 1 97, pp. 1071-1083, 1997) have described the influence of polymerization conditions on the copolymerization of styrene with ethylene using Ziegler-Natta catalysts of Me2Si (Me4Cp) (N-tert-butii) TiCl2 / methylaluminoxane. The ethylene-styrene copolymers produced by bridged metaiocene catalysts have been described by Arai. Toshiaki and Suzuki (Polvmer Preprints, Am. Chem. Soc. Div. Polym, Chem.) Volume 38, pages 349, 350 [1997] and in U.S. Patent No. 5,652,315, issued to Mitsui Toatsu Chemicals, Inc. Manufacturing of the interpolymers of aromatic α-olefin / vinyl monomers such as propylene / styrene and butene / styrene are described in U.S. Patent No. 5,244,996, issued to Mitsui Petrochemical Industries Ltd., or U.S. Patent No. 5,652,315 also issued Mitsui Petrochemical Industries Ltd. or as described in DE 197 1 1 339 A1 of Denki Kagaku Kogyo KK. Also, in spite of the high isotacticity and therefore not "substantially random", the random copolymers of ethylene and styrene are described in Polymer Preprints Vol. 39, No. 1, March 1998 by Toru Aria et al. , they can also be used as mixing components for the foams of the present invention. While preparing the substantially random interpolymer, an amount of atactic vinyl aromatic homopolymer can be formed due to the homopolymerization of the aromatic vinyl monomer at elevated temperatures. The presence of vinyl aromatic homopolymer in general is not detrimental to the purposes of the present invention and can be tolerated. Vinyl aromatic homopolymer can be separated from the interpolymer, if desired, by extraction techniques such as selective precipitation of the solution with a no solvent for the interpolymer or aromatic vinyl homopolymer.

For the purposes of the present invention it is preferred that no more than 30 weight percent, preferably less than 20 weight percent, be present based on the total weight of the atactic vinyl aromatic homopolymer interpolymers. Preparation of the Foams of the Present Invention The compositions of the present invention can be used to form extruded thermoplastic polymer foam, expandable thermoplastic foam beads or expanded thermoplastic foams and molded articles formed by expansion and / or coalescence and welding of these particles. The foams can have any known physical configuration, such as sheet, rod, plank, films and extruded profiles.

The structure of the foam can also be formed by molding the expandable beads in any of the above configurations or any other configuration. The foam structures can be made by a conventional extrusion foam forming process. The present foam is generally prepared by melt mixing in which the aromatic alkenyl polymeric material and one or more substantially random interpolymers are heated together to form a plasticized or molten polymer material, incorporating therein a blowing agent to form a foamable gel and extruding the gel through a nozzle to form the foam product. Prior to the extrusion of the nozzle, the gel is cooled to an optimum temperature. To form a foam, the optimum temperature is above the glass transition temperature or melting point of the mixtures. For the foams of the present invention the optimum foaming temperature is on a scale sufficient to produce an open cell content in the foam of 20 volume percent or less and optimize the physical characteristics of the foam structure. The blowing agent may be incorporated or mixed in the polymeric melt material by any means known in the art such as with an extruder, mixer, blender. The blowing agent is mixed with the melting polymer material at a high enough pressure to prevent substantial expansion of the polymeric melting material and to generally disperse the blowing agent homogeneously therein. Optionally, a nucieador can be mixed in the polymeric fusion or mixed in dry with the polymeric material before the plasticization or casting. The substantially random interpolymers may be dry mixed with the polymeric material before being charged 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 mixed with another device or in separate refrigerators. The gel is then extruded or transported through a nozzle in a desired manner to a zone of reduced pressure or below to form the foam structure. The lower pressure zone is at a lower pressure than that at which the foamable gel is Hold before extrusion through the nozzle. The lower pressure can be superatmospheric or subatmospheric (vacuum), but preferably it is at an atmospheric level. The structures of the present foams can be formed into a coalesced strand form by extruding the compositions of the present invention through a multi-orifice nozzle. The holes are arranged so that contact between the adjacent streams of the molten extrudate occurs during the foaming process and the contacting surfaces adhere to each other with sufficient adhesion that results in a unitary foam structure. The streams of the molten extrudate leaving the nozzle take the form of strands or profiles, which conveniently foam, collide and adhere to each other to form a unitary structure. Conveniently, the coalesced individual strands or profiles must remain adhered in a unitary structure to prevent delamination of stressed strands found in the preparation, formation and use of the foam. Apparatus and method for the production of the coalesced strand-shaped foam structures are found in U.S. Patent Nos. 3,573, 1 52 and 4,824,720. The foam structures present can also be formed by an extrusion process of accumulation as seen in the patent of E. U. No. 4,323,528. In this process, low density foam structures having large cross-sectional and lateral areas are prepared by: 1) formation under pressure of a gel of the compositions of the present invention and an agent of blowing at a temperature at which the viscosity of the gel is sufficient to retain the blowing agent when the gel is allowed to expand; 2) Extrusion of the gel in a holding area maintained at a temperature and pressure that does not allow the gel to be foamed, the fastening area having an outlet nozzle defining a hole that opens towards a lower pressure zone in which the gel forms foam, and a folding gate that closes the orifice of the nozzle; 3) periodic opening of the gate; 4) substantially concurrent application of mechanical pressure by a mobile ram on the gel to expel it from the clamping zone through the orifice of the nozzle towards the lower pressure zone, at a speed greater than that in which the formation of substantial foam in the nozzle orifice and less at which substantial irregularities occur in the cross-sectional area or in the form, and 5) allow the ejected gel to expand unconstrained in at least one dimension to produce the foam structure. The foam structures present can also be formed into degraded foam beads suitable for molding into articles, by expanding pre-expanded beads containing a blowing agent. Pearls can be molded at the time of expansion to form articles in various ways. The processes for forming the expanded pearls and molded expanded bead foam articles are described in Plástic Foams, Part II, Frisch and Saunders, p. 544-585, Marcel Dekker, Inc. (1 973) and Plástic Materoals, Brydson, 5th, Ed., Pp. 426-429, Butterworths (1989).

Expandable and expanded beads can be made by a batch process or by extrusion. The discontinuous process of forming expandable beads is essentially the same as for the manufacture of expandable polystyrene (EPS). The granules of a polymer mixture, formed either by melt mixing or mixing in the reactor, are impregnated with a blowing agent in an aqueous suspension or in an anhydrous state in a pressure vessel and at elevated temperature and pressure. The granules are rapidly discharged in a region of reduced pressure to expand the foam beads or cooled or discharged as non-expanded beads. The non-expanded beads are then heated to expand with appropriate means, for example, with steam or hot air. The extrusion method is essentially the same as for the conventional foam extrusion process as described above for the nozzle orifice. The nozzle has multiple holes. In order to form beads without foam, the foamable strands emerging from the nozzle orifice are immediately cooled in a cold water bath to prevent foaming and then formed into granules. Or, the strands become foam beads cutting into the face of the mouthpiece and then allowed to expand. The foam beads can then be molded by any means known in the art, such as loading the foam beads into the mold, compressing the mold to compress the beads and heating the beads such as with steam to effect coalescence and welding of the beads. pearls to form the article. Optionally, the beads can be impregnated with air or other blowing agent at a high pressure and temperature before being loaded into the mold. In addition, the beads can be heated before being charged. The foam beads can then be molded into blocks or shaped articles by a suitable molding method known in the art (some of the methods are taught in U.S. Patent Nos. 3,504,068 and 3,953,558). The excellent teachings of the above processes and molding methods are observed in C.P. Park, supra, p. 1 91, pp. 197-198 and pp. 227-229. To form the foam beads, mixtures of alkenyl aromatic polymers with one or more substantially random interpolymers are formed in discrete resin particles tai as grained resin granules and suspended in a liquid medium, in which they are substantially insoluble such as Water; they are impregnated with a blowing agent by introducing the blowing agent into the liquid medium at a high pressure and temperature in an autoclave or other pressure vessel; and they are rapidly discharged into the atmosphere or a region of reduced pressure to expand to form the foam beads. This process is taught in the US Patents. Nos. 4,379,859 and 4,464,484. A process for forming expandable thermoplastic beads comprises the proportion of an aromatic alkenyl monomer and optionally at least one additional monomer, which is different, and polymerizable with said aromatic alkenyl monomer; and dissolving in at least one of said monomers of the substantially random interpolymers; polymerization of the first and second monomers to form thermoplastic particles; incorporation of a blowing agent into the thermoplastic particles during or after the polymerization; and cooling the thermoplastic particles to form the expandable beads. The alkenyl aromatic monomer is present in an amount of at least about 50, preferably at least about 70, more preferably at least about 90 percent by weight based on the combined weights of the polymerizable monomers. Another process for the formation of expandable thermoplastic beads comprises: heating the beads of the alkenyl aromatic polymers with one or more substantially random interpolymers to form a molten polymer: incorporating a blowing agent into the molten polymeric material at an elevated temperature. foamable gel; cooling the gel to an optimum temperature which is one at which foaming will not occur, extruding through the nozzle containing one or more orifices to form one or more essentially continuous expandable thermoplastic strands; and forming granules of expandable thermoplastic females to form expandable thermoplastic beads. Alternatively, the expanded thermoplastic foam beads can be made, if before extrusion of the nozzle, the gel is cooled to an optimum temperature in which case it is above the glass transition temperature or melting point of the blends. For the expanded thermoplastic foam beads of the present invention, the optimum foam forming temperature is on a sufficient scale to produce an open cell content in the foam of 20 percent by weight. volume or less. The foam structures present can also be used to form foamed films for boat and other labels, containers using either a blow film or a melt 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 the formation of the present foams include inorganic blowing agents, organic blowing agents and chemical blowing agents. Suitable inorganic blowing agents include nitrogen, sulfur hexafluoride (SFß), argon, water, air and helium. Organic blowing agents include carbon dioxide, aliphatic hydrocarbons having 1-9 carbon atoms, aliphatic alcohols having from 1 to 3 carbon atoms and fully and partially halogenated aliphatic hydrocarbons having from 1 to 4 carbon atoms. The aliphatic hydrocarbons include methane, ethane, propane, n-butane, isobutane, n-pentane, isopentane and neopentane, and the like. 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-difluoroethane (HFC-152a), fluoroethane (HFC-161), 1,1-trifluoroethane (HFC-143a), 1, 1, 1,2-tetrafluoroethane (HFC-1 34a), 1,1, 2,2-tetrafluoroethane (HFC-1 34), 1, 1, 3, 3- pentafluoropropane, pentafluoroethane (HFC-1 25), difluoromethane (HFC-32), perfluoroethane, 2,2, -difluoropropane, 1,1-trifluoropropane, perfluoropropane, dichloropropane, difluoropropane, perfluorobutane, perfluorocyclobutane. The partially halogenated chlorofluorocarbons and chlorofluorocarbons for use in this invention include methyl chloride, methylene chloride, ethyl chloride, 1,11-trichloro-ethane, 1,1-dichloro-1-fluoroethane (HCFC-141 b), 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). Fully halogenated chlorofluorocarbons include trichloromonofluoromethane (CFC-1), dichlorodifluoromethane (CFC-12), trichloro-trifluoroethane (CFC-1 1 3), dichlorotetrafluoroethane (CFC-14), chlorheptafluoropropane and dichlorohexafluoropropane. Chemical blowing agents include azodicarbonamide, azodiisobutyronitrile, benzenesulfonhydrazide, 4,4-oxybenzene, sulfonyl-semicarbazide, p-toluene-sulfonyl semi-carbazide, barium azodicarboxylate, N, N'-dimethyl-N. N'-dinitroso-terephthalamide, trihydrazine triazine and mixtures of citric acid and sodium bicarbonate such as several products sold under the name Hidrocerol ™ (a product and trademark of Boehringer Ingelheim). All of these blowing agents can be used as single components or any combination mixture thereof, or mixed with other co-blowing agents. The amount of blowing agent is incorporated into the polymer melt material to form a polymeric foaming gel of 0.2 to 5.0 grams-moles per kilogram of polymer, preferably of 0. 5 to 3.0 grams-moles per kilogram of polymer and more preferably 1.0 to 2.5 grams-moles per kilogram of polymer. In addition, a nucleating agent can be added in order to control the size of the foam cells. Preferred nucleating agents include inorganic substances such as calcium carbonate, talc, clay, silica, barium stearate, diatomaceous earth, mixtures of citric acid and sodium bicarbonate, and the like. The amount of nucleating agent employed can vary from 0 to 5 parts by weight per hundred parts by weight of a polymeric resin. The preferred scale is from 0 to 3 parts by weight. Various additives may be incorporated into the present foam structure such as inorganic fillers, pigments, antioxidants, acid cleaners, ultraviolet light absorbers, flame retardants, processing aids, extrusion aids, other thermoplastic polymers, unsightly agents and the like. Examples of other thermoplastic polymers include aromatic alkenyl homopolymers or copolymers (having a molecular weight of 2,000 to 50,000) and ethylenic polymers. The foam has a density of from 10 to 95 and more preferably from 1 to 70 kilograms per cubic meter in accordance with ASTM D-1622-88. The foam has an average cell size of 0.05 to 5.0, preferably 0.1 to 1.5 millimeters in accordance with ASTM D3576-77. The foam present in particular is suitable to be formed in a plank or sheet conveniently one tending a thickness or smaller dimension in cross section of 30 square centimeters (cm) or more and a thickness or smaller dimension in cross section of 0.95 cm or more, preferably 2.5 cm or more. The foam present is closed cell. The closed cell content of the foam present is greater than or equal to 80 percent in accordance with ASTM D2856-94. The heat distortion temperature of the present foam is increased 2 ° C or more, preferably 3 ° C or more, and more preferably 5 ° C or more, relative to the heat distortion temperature of a corresponding foam made without the interpolymer substantially random. The present foam structures can be used to isolate a surface by applying an insulating panel coated with the present structure to the surface, as used in for example, external cover wall (local thermal insulation), foundation insulation, and residence basements . Such panels are useful in conventional insulation applications such as roofs, constructions, refrigerators and the like. Other applications include springs and floating rafts (flotation applications) as well as various floral and craft applications. Properties of the Interpolymers and Mixture Compositions Used to Prepare the Foams of the Present Invention The polymeric compositions used to prepare the foams of the present invention comprise from 80 to 98, preferably from 85 to 97, more preferably from 90 to 95 percent by weight. weight, (based on the combined weights of the substantially random interpolymer and aromatic homopolymers or alkenyl copolymers) of one or more alkenyl aromatic homopolymers or copolymers. The molecular weight distribution (Mw / Mn) of the alkenyl aromatic homopolymers or copolymers used to prepare the foams of the present invention is from 2 to 7. The molecular weight (Mw) of the aromatic aanyl homopolymers or copolymers used to prepare the foams of the present invention is from 1,000,000 to 500,000, preferably from 120,000 to 350,000, more preferably from 130,000 to 325,000. The aromatic alkenyl polymeric material used to prepare the foams of the present invention comprises more than 50 and preferably more than 70 weight percent of the alkenyl aromatic monomer units. More preferably, the aromatic alkenyl polymer material is comprised entirely of alkenyl aromatic monomer units. The polymeric compositions used to prepare the foams of the present invention comprise from 2 to 20, preferably from 3 to 15, more preferably from 5 to 10 weight percent (based on the combined weights of the substantially random interpolymer and the homopoiomers and copolymers alkenyl aromatics) of one or more substantially random interpolymers. These substantially random interpolymers used to prepare the foams of the present invention usually contain from 21 to 65, preferably from 29 to 52, more preferably from 29 to 45, mole of at least one aromatic vinyl or vinylidene monomer and / or vinylidene, vinylidene, aliphatic or cycloaliphatic monomer and to 79, preferably from 48 to 71, more preferably from 55 to 71 mole percent of ethylene and / or at least one aliphatic α-olefin having from 3 to 20 carbon atoms. The melt index (12) of the substantially random interpolymer used to prepare the foams of the present invention is 0.1 to 50, preferably 0.3 to 30, more preferably 0.5 to 10 g / 10 min. The molecular weight distribution (Mw / Mn,) 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 , minor amounts of aromatic alkenyl copolymers or homopolymers or copolymers having a molecular weight of 2,000 to 50,000, preferably 4,000 to 25,000 can be aerated in an amount not exceeding about 2 percent by weight (based on the combined weights of the substantially random interpolymer and various aromatic homopolymers or alkenyl copolymers). The following examples are illustrative of the invention, but can not be considered as limiting the scope thereof in any way. EXAMPLES Test Methods a) Density and Fusion Flow Measurements The molecular weight of the substantially random interpolymers used in the present invention was conveniently indicated using the melt index measurement according to ASTM D-1238, Condition 1 90 ° C / 2.1 6 kg. (formally known as "Condition (E)" and also known as LI2). The melt index inversely is proportional to the molecular weight of the polymer. Therefore, the higher the lower molecular weight, the lower the melting index, although the relationship is not linear. Also, to indicate the molecular weight of the substantially random interpolymers used in the present invention, the Gottfert melting index (G) is useful., cm3 / 1 0 min.) which is obtained in a similar manner as the melt index (12) using the method of ASTM D1238 for automatic plastometers, with the melt density equipment at 0.7632, the melt density of polyethylene a 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 for a scale of 29.8 percent to 81.8 percent by weight of styrene . The levels of atactic polystyrene in these samples typically were typically 10 percent or less. The influence of atactic polystyrene was assumed to be minimal due to low levels. Also, the melting density of the atactic polystyrene and the melting densities of the samples with the top totai styrene are very similar. The method used to determine the melt density employed in a Gottfert melt index machine with a melting density parameter set at 0.7632 and the collection of strands of fusion as a function of time while the weight of l2 is a force.

The weight and time for each normal melt was recorded and normalized to give the mass in grams per 10 minutes. The value of the fusion index l2 of the instrument was also recorded. The equation used to calculate the actual fusion density is d = d0 .. 63_ x l2 / l2 Gottfert where d0. 63_ = 0.7632 and l2 Gottfert = melt index displayed.

A linear least squares fit of the 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 = weight percentage of styrene in the polymer. The ratio of the total styrene to the melt density can be used to determine a current melt index value, using these equations if the styrene content is known. In this way for a polymer that is 73 percent of the total styrene content with a measured melt flow (the "Gottfert number"), the calculation can be: d = 0.00299 * 73 + 0.723 = 0.941 2 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 were determined using proton nuclear magnetic resonance (1 HN M.R). All proton NMR samples were prepared in 1,1,1,2-tetrachloroethane-d2 (TCE-d2). The resulting solutions were 1.6 - 3.2 weight percent of the polymer. The melt index (12) was used as a guide to determine the sample concentration. Therefore, when the l2 is greater than 2 g / 1 0 min. , 40 mg of the interpolymer are used; when one l2 between 1.5 and 2 g / 10 min. , 30 mg of the interpolymer is used; and when the l2 is less than 1.5 g / 10 min., 20 mg of interpolymer is used. The interpolymers were directly weighed in 5 mm sample tubes. An aliquot of 0.75 mL of TCE-d2 was added by syringe and the tube was covered with a tight-fitting polyethylene layer. The samples were heated in a water bath at 85 ° C to soften the interpolymer. To provide mixing, the stoppered samples were occasionally raised to the reflux temperature using a heat gun. The proton NMR spectrum was accumulated in a Varian VXR 300 apparatus with the sample probe at 80 ° C, and reference was made to the residual protons of TCE-d2 at 5.99 ppm. The delay times varied between 1 second and the data was recovered in triplicate in each sample. The following instrumental conditions were used for the analysis of the Varian VRX-300 interpolymer samples, normal 1 H Scan Width, 5000 Hz Acquisition Time, 3,002 sec, Impulse Width, 8 μsec Frequency, 300 MHz, Delay, 1 sec . , Temporary, 16 The total analysis time per sample was approximately 10 minutes. Initially, a 1H NMR spectrum for a polystyrene sample, having a molecular weight (Mw) of about 192,000, was acquired with a one-second display time. The protons were "marked": b, branched; 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; the "A" is designated aPS. The integral A7.? , (aromatic, around 7.1 ppm) is thought to be three ortho / para protons; and the integral A6.6, (aromatic, around 6.6 ppm) the two meta protons. The two aliphatic protons labeled resonate at 1.5 ppm; and the single labeled proton b is at 1.9 ppm. The aliphatic region was integrated from 0.8 to 2.5 ppm and was referred to as Aa? . The theoretical proportion for A7.1; A6.e; to? is 3: 2: 3, or 1.5: 1: 1.5 and correlated very well with the observed proportions for the polystyrene sample during several 1 second delay times. The proportion calculations used to verify the integration and verify the peak assignments were carried out dividend the appropriate integral by the integral A6 6; Proportion Ar is A7.?/A6.6 The region A6.β was assigned the value of 1. The proportion Al is integral Aa? / A6.6. All the collected spectra have the integration ratio 1 .5: 1: 1 .5 of (or + 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 ethylene / styrene interpolymers, the 1H spectrum NMR using a delay time of one second, had the integrals C7 1, C6.6, and Ca? defined, so that the integration of the peak at 7.1 ppm includes all the aromatic protons of the copolymer as well as the protons or & p from aPS. Similarly, the integration of the aliphatic region Ca? in the aspect of the interpolymers it includes aliphatic protons of both aPS and the interpolymer with a transparent baseline that resolves the signal of any polymer. The integral of the peak at 6.6 ppm Ce. E is resolved from the other aromatic signals and is thought to be due to only the aPS homopolymer (probably the target protons). (The assigned peak for atactic polystyrene at 6.6 ppm (integral A6.e) was formed based on the comparison of the authentic polystyrene sample having a molecular weight (Mw) of approximately 192,000.This is a reasonable assumption since, At very low levels of atactic polystyrene, only a very weak signal is observed, so phenyl protons in the copolymer do not contribute to this signal. assumption, the integral A6 e becomes the basis for quantitatively determining the content of aPS. The following equations were then used to determine the degree of styrene incorporation in the ethylene / styrene interpolymer samples: (Phenyl C) = C7 + A71 - (1.5 x Aβ 6) (Aliphatic C) = Ca? - (1.5 x A66) Sc = (Phenyl C) / 5 ec = (Aliphatic C - (3 x sc)) / 4 E = ec / (ec + sc) -c - Sc / (6c "*" Sc and the The following equations were used to calculate the mole percentage of ethylene and styrene in the interpolymers. % by weight E: E'28 - (. 00.}. (E'28) + (Sc * 104) in nes or S Sc "104 - (IOOÍ (E'28) + (SC104) wherein: sc and ec are proton fractions of ethylene and styrene in the interpolymer, respectively, Sc and E are molar fractions of the styrene monomer and ethylene monomer in the interpolymer respectively. The weight percentage of aPS in the interpolymers was then determined by the following equation: The total styrene content was also determined by quantitative Fourier Transform Infrared Spectroscopy (FTIR). Preparation of Ethylene / Styrene Interpolymers ("ESL's") Used in the Examples and Comparative Experiments of the Present Invention 1) Preparation of ESI # 's 1 -3 ESI #' s 1 -3 are substantially random ethylene / styrene interpolymers prepared using the following catalysts and polymerization procedures. Preparation of Catalyst A; (1 H-cyclopentari-l-phenanthrene-2-yl) dimethyl (t-butylamido) -silanetitanium 1,4-diphenylbutadiene) 1) Preparation of 1 H-cyclopenta [1] phenanthrene-2-yl of lithium To a round-bottomed flask of 250 ml containing 1.42 g (0.00657 mol) of 1 H-cyclopenta [1] phenanthrene and 120 ml of benzene were added dropwise, 4.2 ml of a 1.60 M solution of n-BuLi in mixed hexanes. The solution was allowed to stir overnight. The lithium salt was isolated by filtration, washed twice with 25 ml of benzene and dried under vacuum. The isolated yield 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) was added dropwise a solution of 1.45 g (0.0064 mol) 1 H-cyclopenta [1] phenanthrene-2-yl of lithium in THF. The solution was stirred for approximately 16 hours, after which the solvent was removed under reduced pressure, giving an oily solid which was extracted with toluene, filtered through the diatomaceous earth filter medium (Celite ™), washed twice with toluene and dried under reduced pressure. . The isolated yield was 1.98 g (99.5 percent). 3. Preparation of (1 H-cyclopenta [1] phenanthrene-2-yl) dimethyl (t-butylamido) silane To a 500 ml round bottom flask containing 1.98 (0.0064 mole) of (1 H-cyclopenta [1] phenanthrene-2-yl) dimethylchlorosilane and 250 ml of hexane were added 2.00 ml (0.0160 mol) of t-butylamine. The reaction mixture was allowed to stir for several days, then filtered using the diatomaceous earth filter medium (Celite ™), washed twice with hexane. The product was isolated by removing the residual solvent under reduced pressure. The isolated yield 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-butylamido) silane) and 120 ml of benzene was added dropwise 3.90 ml of a solution of n-BuLi 1.6 M in mixed hexanes. The reaction mixture was stirred for about 16 hours. The product was isolated by filtration, washed twice with benzene and dried under reduced pressure. The isolated yield 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 »3THF and approximately 120 ml of THF were added at a rapid drop rate of 50 ml of a THF solution of 1.08 g of dilitium (1 H-cyclopenta [1] phenanthrene-2-yl) dimethyl (t-butylamido) siRNA. The mixture was stirred at about 20 ° C for 1.5 hours at which time 0.55 mg (0.002 mole) of solid PbCI2 was added. After stirring for an additional 1.5 hours the THF was removed under vacuum and the residue was extracted with toluene, filtered and dried under reduced pressure to give an orange solid. The yield was 1.3 g (93.5 percent). 6. Preparation of 1,4-diphenylbutadiene from (1 H-cyclopenta [1] phenanthrene-2-yl) dimethyl (t-butylamido) silanetitanium To a dichloride paste of (1 H-cyclopenta [1] phenanthrene-2-yl) dimethyl (t-butylamido) silanetitanium (3.48 g, 0.0075 mol) 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 1.6 M solution of n-BuLi (0.01 50 moles). The solution darkened immediately. The The temperature was increased to bring the mixture to reflux and the mixture was kept at the temperature for 2 hours. The mixture was cooled to about -20 ° C and the volatiles were removed under reduced pressure. The residue was mixed in 60 ml of hexanes mixed at about 20 ° C for about 16 hours. The mixture was cooled to about -25 ° C for about 1 hour. The solids were recovered in a glass fiber by vacuum filtration and dried under reduced pressure. The dried solid was placed in a glass fiber nozzle and the solid was continuously extracted with hexanes using a Soxhiet extractor. After 6 hours 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 discharged. The solids in the extractor were stirred and the extraction was continued with an additional amount of mixed hexanes to give an additional 0.46 mg of the desired product as a dark crystalline solid.

Polymerization for ESI # 1 -3 ESl's 1 -3 were prepared in a continuous operation cycle reactor (1 39 L). An Ingersoli-Dreser double screw pump provided mixing. The reactor ran the complete liquid at 3,275 kPa with a residence time of approximately 25 minutes. The raw materials and the catalyst / cocatalyst streams were fed into the suction of the twin screw pump through Ken ics static mixers and injectors. The double screw pump was discharged in a line with a diameter of 5.08 cm that supplied two heat exchangers of Multiple BEM Tubes Type 1 0-68 of Chemineer-Kenics in series. The tubes of these exchangers contained twisted ribbons to increase heat transfer. Upon leaving the last exchanger, the cycle flow back through the injectors and the static mixers to the suction pump. The heat transfer oil was calculated through the jacket of the exchangers to control the temperature probe of the cycle located just before the first exchanger. The output current of the cycle reactor came out between the two exchangers. The flow and solution density of the output stream was measured by a MicroMotion. The solvent fed to the reactor was supplied by two different sources. A fresh toluene stream from a 8480-S-E Pulsafeeder diaphragm pump with speeds measured by a MicroMotion flow meter was used to provide rinsing flow to the reactor seals (9.1 kg / hr). The recycled solvent was mixed with unenhanced styrene monomer on the suction side of five diaphragm pumps 8480-5-E Pulsafeeder in parallel. These five Pulsafeeder pumps supplied solvent and styrene to the reactor at 4,583 kPa. The fresh styrene flow was measured by a MicroMotion flow meter and the total recycled solvent / styrene flow was measured by a separate MicroMotion flow meter. Ethylene was supplied to the reactor at 4,838 kPa. The ethylene stream was measured by a Micro-Motion mass flow meter. 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 was combined with the solvent / styrene stream at room temperature. The temperature of the complete inlet feed stream as it enters the reactor cycle was decreased to 2 ° C by an exchange with -1 0 ° C of glycol on the cover. The preparation of these three catalyst components took place in three separate tanks: the fresh solvent and the concentrated catalyst / cocatalyst pre-mix was added and mixed in their respective operation tanks and fed into the reactor via the diaphragm pumps of Pulsofeeder 680-S-AEN7 variable speed. As previously explained, the three components of the catalyst systems enter the reactor cycle through an injector and the static mixer on the suction side of the twin screw pump. The feed stream from the raw material was also fed into the reactor cycle through the injector and the static mixer downstream of the catalyst injection point but upstream of the twin screw pump suction. The polymerization was stopped with the addition of the destroyed catalyst (water mixture with solvent) in the product line after the Micro-Motion flow meter measured the density of the solution. A static mixer in the line provided the dispersion of the destroyed catalyst and the additives in the stream leaving the reactor. This current then enters the post-reactor heaters which provide additional energy for the solvent removal pulse. This impulse occurred as the effluent leaves the heater after the reactor and the pressure decreased from 3,275 kPa to less than 60 kPa absolute pressure in the pressure control valve of the reactor. This driven polymer first entered the two devolatilizers covered with hot oil. Volatiles driven from the first devolatilizer were condensed with a glycol shell exchanger, passed through the suction of a vacuum pump and discharged into the styrene / ethylene and solvent separation vessel. The solvent and styrene were removed from the bottom of this container as the recycled solvent while the ethylene was expelled from the top. The ethylene stream was measured with a MicroMotion mass flow meter. The measurement of ventilated ethylene plus a calculation of dissolved gases in the solvent / styrene stream were used to calculate the ethylene conversion. The remaining polymer and 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 drive 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 a granule former under water with a 6-hole nozzle, formed into granules, dried by rotation and recovered in 450-well boxes. kg. The different catalysts, co-catalysts and process conditions used to prepare the different ethylene-interpolymers Individual styrene (ESI # / s 1 -3) are summarized in Table 1 and their properties are summarized in Table 2.

Table I Preparation Conditions for ESI # 's 1 -3 * N / D = Not available to Catalyst A is (1 H-cyclopenta [1] phenanthrene-2-yl) dimethyl (t-butylamido) -silanetitanium 1,4-diphenylbutadiene) b Cocatalyst B is tris (pentafluoropheni) borane, ( CAS # 001 109-15.5). c a methyl methylaluminoxane commercially available from Akzo Nobel as MMAO-3A (CAS # 146905-79-5). Table 2. Properties of ESI # 's 1 -3 Additional Blending Components PS 1 is a granular polystyrene having a weight average molecular weight, Mw of 296,000 and a polydispersity of Mw / Mn of about 2.7. PS 2 is a granular polystyrene having a weight average molecular weight, Mw of 148,700 and a polydispersity of Mw / Mn of approximately 5.5. Examples 1 -2 A foaming process comprising a single screw extruder, mixer, coolers and nozzle was used to form foam sheets. HCFC-22 was used as the blowing agent at a level of 5.7 part percent resin (phr) for foaming PS and PS / ESI blends. Talc was used as a nucleator. All foams were made at 140 ° C. Table 3 summarizes the properties of the foam. Example 3 A foaming process comprising a single screw extruder, mixer, coolers and nozzle was used to form foam boards. The carbon dioxide (CO2) was used as the blowing agent at a level of 4.7 phr, to foam the polystyrene and a polystyrene mixture with ESI. Other additives were: hexabromocyclododecane = 2.5 phr; barium stearate = 0.2 phr; blue dye = 0.15 phr; tetrasodiumpyrophosphate = 0.2 phr; Linear low density polyethylene = 0.4 phr. The foaming temperature was 1 23 ° C. The data of Examples 1 - 3 show that the distortion temperatures of the foams of the present invention were significantly higher than those of the comparative foams made without the substantially random interpolymer blend component. Additionally, the other physical and mechanical properties of the foams were generally similar to, or better than, those of the comparative foams.

Table 3. Heat Distortion Temperatures Increased with PS / ESI Mixtures, Using HCFC-22 as the Blowing Agent Ji- O Table 4. Heat Distortion Temperatures Increased with PS / ES1 Mixtures Using CQ2 as Blowing Agents Ü1 or

Claims (29)

1. CLAIMS 1. A process for the formation of a closed cell alkenyl aromatic polymer foam having increased heat distortion temperature, said process comprising; (I) forming a polymeric melting material comprising; (A) from 80 to 98 weight percent (based on the combined weight of Components A and B) of one or more alkenyl aromatic polymers and wherein at least one of said alkenyl aromatic polymers has a molecular weight ( Mw) from 100,000 to 500,000; and (B) from 2 to 20 weight percent (based on the combined weight of Components A and B) of one or more substantially random interpolymers having a 12 from 0.1 to 1000 g / 1 0 min, one Mw / Mn, from 1.5 to 20; who understands; (1) from 21 to 65 mole percent of the polymer units derived from: (a) at least one vinyl or vinylidene aromatic monomer, or (b) at least one aliphatic or cycloaliphatic vinylidene or hidden cycloaliphatic monomer, or (c) a combination of at least one aromatic vinyl or vinylidene monomer and minus one aliphatic or cycloaliphatic vinylidene or hidden vinylidene monomer, and (2) from 35 to 79 mole percent polymeric units derived from at least one of ethylene and / or C3.20 α-olefin; and (3) from 0 to 20 mole percent of polymer units derived from one or more polymerizable ethylenically unsaturated monomers other than those derived from (1) and (2); and (C) optionally, one or more nucleating agents; and (D) optionally, one more different additives; Y (II) further incorporate in said polymeric melt material at an elevated pressure to form a foamable gel (E) one or more blowing agents present in a total amount of 0.2 to 5.0 grams-moles per kilogram (based on the combined weight of Components A and B); (III) cooling said foamable gel to an optimum temperature; Y (IV) extrude the gel from Step I I I through a nozzle to a lower pressure region to form a foam, or a result of said process the distortion temperature said foam is increased by approximately 2 ° C or more relative to a corresponding foam without the substantially random interpolymer. The process according to claim 1, characterized in that said foam has a thickness of 0.95 cm or more and wherein (A) in the Component (A), said at least alkenyl aromatic polymer is more than 50 weight percent of alkenyl aromatic monomer units and has a molecular weight (Mw) of from 120,000 to 350,000 and is present in an amount of from 85 to 97 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, from 1 .8 to 10; it is present in an amount of from 3 to 15 weight percent (based on the combined weight of components A and B); and comprises (1) from 29 to 52 mole percent of polymer units derived from; (a) said vinylidene or vinyl aromatic monomer represented by the following formula: A1 i - c = CH. wherein R1 is selected from the group of radicals consisting of radicals of hydrogen and alkyl containing three carbons or less, and Ar is a phenyl group or a phenyl group substituted with from 1 to 5 substitutes selected from the group consisting of halo, C 1-4 alkyl, and C? -4 haloalkyl; or (b) said aesthetically concealed aliphatic or vinylidene vinylidene or cycloaliphatic monomer, 10 is represented by the following general formula: ? »L R l C = C < R *) Z wherein A1 is an aliphatic substitute or 15 sterically bulky cycloaliphatic of up to 20 carbons, R1 is selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms, preferably Hydrogen and methyl, each R 2 independently is selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms, preferably hydrogen or methyl; or alternatively R1 and A1 together they form a ring system; or (c) a combination of a and b; and (2) from 48 to 71 mole percent of polymer units derived from ethylene and / or said olefin that comprises at least one of propylene, 4-methyl-1-pentene, butene-1, hexane-1 or octene- 1; and (3) said polymerizable ethylenically unsaturated monomers other than those derived from (1) and (2) comprise norbornene or a norbornene substituted with C6-? o aryl or a C? -? 0 alkyl; and (C) said nucleating agent, if present, Component (C), comprises one or more of calcium carbonate, talc, clay, silica, barium stearate, diatomaceous earth, mixtures of citric acid and sodium bicarbonate; Y (D) said additive, if present, Component (D), comprises one or more of the inorganic fillers, pigments, antioxidants, acid cleaners, ultraviolet light absorbers, other thermoplastic polymers, antistatic agents, flame retardants, auxiliary processing, extrusion auxiliaries; 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 Components A and B), and comprises one or more of the inorganic blowing agents, organic blowing agents and / or chemical blowing agents. wherein the heat distortion temperature of said foam is increased by 3 ° C or more relative to a corresponding foam without the substantially random interpolymer. 3. The process according to claim 1, characterized in that said foam has a thickness of 2.5 cm or more and wherein; (A) in Component (A), said at least alkenyl aromatic polymer has more than 70 weight percent aromatic alkenyl monomer units, has a molecular weight (Mw) of from 130,000 to 325,000, a weight distribution molecular, (Mw / Mn) from 2 to 7, and is present in an amount of from 90 to 95 weight percent (based on the combined weight of 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 present in an amount of from 5 to 10 percent by weight (based on the combined weight of components A and B); and comprises (1) from 29 to 45 mole percent of polymer units derived from; (a) said vinyl aromatic monomer comprising styrene, α-methyl styrene, ortho-, meta- and para-methylstyrene, and halogenated styrene rings, or (b) said vinyl or vinylidene, aliphatic or cycloaliphatic monomers comprising -ethylidene-2-norbornene or 1-vinylcyclohexene, 3-vinylcyclohexene and 4-vinylcyclohexene; or (c) a combination of a and b; and (2) from 55 to 71 mole percent of polymer units derived from ethylene and / or said α-olefin comprising ethylene, or ethylene and at least one of propylene, 4-methyl-1-pentene, butene-1 , hexane-1 or octene-1; and (3) said polymerizable ethylenically unsaturated monomers other than those derived from (1) and (2) are norbornene; and (C) said nucleating agent, if present, Component (C), comprises one or more of talc 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 (E) said blowing agent, Component (E), is present in a total amount of from 1.0 to 2.5 grams- moles per kilogram (based on the combined weight of Components A and B), and comprising one or more of nitrogen, sulfur hexafluoride (SF6), argon, carbon dioxide, water, air and helium, methane, ethane, propane , n-butane, isobutane, n-pentane, sopentane, neopentane, methanol, ethanol, n-propanol and isopropanol, methyl fluoride, perfluoromethane, ethyl fluoride, 1,1-difluoroethane (HFC-152a), fluoroethane (HFC) -161), 1, 1, 1 -trif luoroethane (HFC-143a), 1,1,1,2-tetrafluoroethane (HFC-134a), 1, 1, 2,2-tetrafluoroethane (HFC-134), 1,1,1,3,3-pentafluoropropane, pentafluoroethane (HFC-125), difluoromethane (HFC-32), perfluoroethane, 2,2, -difluoropropane , 1,1-trifluoropropane, perfluoropropane, 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), trichloro-trifluoroethane (CFC-113), dichlorotetrafluoroethane (CFC-114), chlorheptafluoropropane, dichlorohexafluoropropane, azodicarbonamide, azodiisobutyro-nitrile, benzenesulfonhydrazide, 4,4-oxybenzene, suifonyl-semicarbazide, p-toluene-sulfonyl-semi-carbazide, barium azodicarboxylate, N, N'-dimethyl-N, N'-dinitrosotero-phthalamide, trihydrazino triazine and mixtures of citric acid and sodium bicarbonate; and wherein the heat distortion temperature of said foam is increased by 5 ° C or more relative to a corresponding foam without the substantially random interpolymer. The process according to claim 3, characterized in that said alkenyl aromatic polymer, component (A), is polystyrene, Component B is an ethylene / styrene copolymer and the blowing agent, Component (E), is one or more than carbon dioxide, propane, n-butane, isobutane, n-pentane, isopentane, neopentane, ethanol, 1,1-difluoroethane (HFC-152a), 1,1,1,2-tetrafluoroethane (HFC-134a), ethyl chloride, 1-chloro-1,1-difluoroethane (HCFC-142b), 1,1,2,2-tetrafluoroethane (HFC-134) or chlorodifluoromethane (HCFC-22). The process according to claim 3, 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 dioxide carbon, propane, n-butane, isobutane, n-pentane, isopentane, neopentane, ethanol, 1,1-difluoroethane (HFC-152a), 1,1,1,2-tetrafluoroethane (HFC-134a), ethyl chloride , 1-chloro-1,1-difluoroethane (HCFC-142b) 1,1,2,2-tetrafluoroethane (HFC-134), or chlorodifluoromethane (HCFC-22). 6. The process according to claim 1, characterized in that the foam has a density of from 10 to 1 50 kilograms per cubic meter (kg / m3) and a cell size of 0.05 to 5.0 millimeters. 7. The process according to claim 1, characterized in that the foam has a density of from 10 to 70 kg / m3 and a cell size of 0.1 to 1.5 millimeters. 8. The process according to claim 1, characterized in that the aromatic alkeneium polymeric material comprises more than 70 weight percent of alkenyl aromatic monomer units, the substantially random interopolymer is incorporated to increase the heat distortion temperature by 5 ° C. or more relative to a corresponding foam without the substantially random interpolymer, and the foam has a density of 10 to 150 kg / cm 3 and a cell size of 0.05 to 5.0 millimeters. The process according to claim 1, characterized in that the aromatic alkenyl polymeric material comprises more than 70 weight percent of alkenyl aromatic monomer units, the substantially random interopolymer is incorporated to increase the heat distortion temperature by 5 ° C. or more relative to a corresponding foam without the substantially random interpolymer, and the foam has a density of from 10 to 70 kg / cm 3 and a cell size of 0.1 to 1.5 millimeters. The process according to claim 1, characterized in that in step (IV) said foamable gel is extruded through a multi-orifice nozzle to a lower pressure region in a manner that contact between the adjacent streams of the molten 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 strand foam. eleven . The process according to claim 1, characterized in that in step (IV) the foamable gel is: (1) extruded in a holding area maintained at a temperature and pressure that does not allow the gel to be foamed, the holding area having an outlet nozzle and an open orifice in a zone of lower pressure at which the gel is foamed and a folding gate that closes the orifice of the nozzle; (2) periodically opens the gate; (3) applies mechanical pressure substantially concurrently by a moving ram on the shaft to expel it from the clamping area through the nozzle orifice in the lower pressure zone, at a speed greater than that at which the forming process of substantial foam in the nozzle orifice occurs and less than that in which the irregularities in cross-sectional shape or area occur; and (4) allows the ejected gel to expand without restriction in at least one dimension to produce the foam structure. The process according to claim 1, characterized in that the foamable gel of step (II) is cooled to an optimum temperature at which no foaming occurs and then extruded through a nozzle to form an expandable thermoplastic strand. It continues to form into granules to form expandable thermoplastic beads. 3. The process according to claim 1, characterized in that in step (IV) said foamable gel is extruded through a nozzle to form essentially continuous expanded thermoplastic strands which are converted into foam beads by cutting on the face of the nozzle and then allowing expansion. 14. A process for making a closed cell alkenyl aromatic foam in the form of thermoplastic foam beads having increased heat distortion temperature, said process comprising: (I) forming a polymeric melting material comprising; (A) from 80 to 98 weight percent (based on the combined weight of Components A and B) of one or more alkenyl aromatic polymers and wherein at least one of said alkenyl aromatic polymers has a molecular weight ( Mw) from 1,000,000 to 500,000; and (B) from 2 to 20 weight percent (based on weight combined of Components A and B) of one or more substantially random interpolymers having a 12 of 0.1 to 1000 g / 10 min, one Mw / Mn, of 1.5 to 20; who understands; (1) from 21 to 65 mole percent of the polymer units derived from: (a) at least one vinyl or vinylidene aromatic monomer, or (b) at least one monomer of 10 vinylidene or aliphatic or occult cycloaliphatic vinylidene, or (c) a combination of at least one vinyl vinylidene aromatic monomer and at least one 15 an aliphatic or cycloaliphatic vinylidene or vinylidene monomer, and (2) from 35 to 79 mole percent polymeric units derived from at least one of ethylene and / or α-olefin 20 of C3.20; and (3) from 0 to 20 mole percent polymer units derived from one or more different polymerizable ethylenically unsaturated monomers 25 to those derived from (1) and (2); Y (C) optionally, one or more nucleating agents; and (D) optionally, one more different additives; and (II) cooling and granulating the product of step I to form discrete resin particles; and (III) suspending said resin particles in a liquid medium in which they are substantially insoluble; (IV) incorporating in the suspension formed in Step III at a high temperature and pressure in an autoclave or other pressure vessel; (E) one or more blowing agents present in a total amount of from 0.2 to 5.0 grams-moles per kilogram (based on the combined weight of Components A and B); (V) Quickly download the product formed in the Stage IV in the atmosphere, or a region of reduced pressure, to form foam beads; wherein the heat distortion temperature of said foam is increased by 2 ° C or more relative to a corresponding foam without the substantially random interpolymer. 1 5. A process for making thermoplastic, expandable foam beads, such process comprises; (I) provide; (A) an aromatic alkenyl monomer and optionally a second monomer, which is different from and copolymerizable with said aromatic alkenyl monomer. (II) dissolving in at least one of said monomers; (B) one or more substantially random interpolymers comprising polymer units derived from; (a) at least one vinyl or vinylidene aromatic monomer, or; (b) at least one vinyl monomer or 10 aliphatic or hidden cycloaliphatic vinylidene, or (c) a combination of at least one vinyl vinylidene aromatic monomer and at least one aliphatic or cycloaliphatic vinylidene or hidden cycloaliphatic monomer, and 15 (2) polymer units derived from at least one of ethylene and / or C3-20 α-olefin; and optionally (3) polymer units derived from one or more ethylenically polymerizable monomers 20 unsaturates different from those derived from (i) and (2); and (C) optionally, one or more nucleating agents; (D) optionally, one more different additives; and 25 (I II) polymerize the product of Step I I to form thermoplastic particles; and incorporate during and / or after the polymerization; (E) one or more blowing agents in the thermoplastic particles; and (V) cooling the thermoplastic particles to form expandable foam beads. 16. The process according to claim 15, characterized in that; (A) said monomer (s) is (are) present in an amount of from 80 to 98 weight percent (based on the combined weight of Components A and B); and (B) said one or more substantially random interpolymers has 0.1 0.1 to 1000 g / 10 min. , and one Mw / Mn, from 1.5 to 20; and is present in an amount of from 2 to 20 weight percent (based on the combined weight of components A and B); and comprises (1) from 21 to 65 mole percent of polymer units derived from; (a) at least one vinyl or vinylidene aromatic monomer, or; (c) at least one aliphatic or cycloaliphatic vinylidene or hidden cycloaliphatic vinyl monomer, or (c) a combination of at least one vinyl vinyl or aromatic vinylidene monomer and at least one aliphatic or cycloaliphatic vinylidene or vinylidene monomer, and (2) from 35 to 79 mole percent polymeric units derived from at least one of ethylene and / or α-olefin C3.20; and (3) from 0 to 20 mole percent of polymer units derived from one or more polymerizable ethylenically unsaturated monomers other than those derived from (1) and (2); and (C) optionally, one or more nucleating agents; and (D) optionally, one more different additives; and (E) one or more blowing agents present in a total amount of from 0.2 to 5.0 gram-moles per kilogram (based on the combined weight of Components A and B). 1 7. The process according to claim 1 5, characterized in that; (A) said monomer (s) is (are) present in an amount of from 85 to 97 weight percent (based on the combined weight of Components A and B); and (B) said one or more interpolymers substantially Random has a l2 0.3 to 30 g / 10 min. , and an Mw / Mp, from 1 .8 to 10; and is present in an amount of from 3 to 15 weight percent (based on the combined weight of components A and B); and comprises (1) from 29 to 25 mole percent of polymer units derived from; (a) said vinylidene or vinyl aromatic monomer represented by the following formula: 10 Al I Ri C: CH wherein R1 is selected from the group of radicals consisting of hydrogen and alkyl radicals containing three 15 carbons or less, and Ar is a phenyl group or a phenyl group substituted with from 1 to 5 substitutes selected from the group consisting of halo, C? -4 alkyl, and C? Haloalkyl.; or 20 (b) said aliphatic vinylidene or aesthetically hidden cycloaliphatic vinylidene monomer is represented by the following general formula: 25 A 'R l C ~ C (R2) Z wherein A1 is a sterically bulky aliphatic or cycloaliphatic substitute of up to 20 carbons, R1 is selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms, preferably hydrogen and methyl, each R2 10 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; or alternatively R1 and A1 15 together form a ring system; or (c) a combination of a and b; and (2) from 48 to 71 mole percent of polymer units derived from ethylene and / or said α-olefin comprising at least one of propylene, 4-methyl-1-20 pentene, butene-1, hexane-1 or octene - 1; and (3) said polymerizable ethylenically unsaturated monomers other than those derived from (1) and (2) comprise norbornene or a norbornene. 25 substituted with C6-aryl or a C1-10 alkyl; Y (C) said nucleating agent, if present, Component (C), comprises one or more of calcium carbonate, talc, clay, silica, barium stearate, diatomaceous earth, mixtures of citric acid and sodium bicarbonate; Y (D) said additive, if present, Component (D), comprises one or more of the inorganic fillers, pigments, antioxidants, acid cleaners, ultraviolet light absorbers, other thermoplastic polymers, antistatic agents, flame retardants, auxiliary processing, extrusion auxiliaries; 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 Components A and B), and comprises one or more of inorganic blowing agents, organic blowing agents and / or chemical blowing agents. 18. The process according to claim 1 5, characterized in that; (A) said monomer (s) is (are) present in an amount of from 90 to 95 weight percent (based on the combined weight of Components A and B); and (B) said substantially random interpolymer, Component (B), has u n l2 from 0.5 to 10 g / 10 min. and an Mw / Mn of 2 to 5; and is present in an amount of from 5 to 10 weight percent (based on the combined weight of components A and B); and comprises (1) from 29 to 45 mole percent of polymer units ded from; (a) said vinyl aromatic monomer comprising styrene, α-methyl styrene, ortho-, meta- and para-methylstyrene, and halogenated styrene rings, or (b) said vinyl or vinylidene, aliphatic or cycloaliphatic monomers comprising -ethylidene-2-norbornene or 1-vinylcyclohexene, 3-vinylcyanohexene and 4-vinylcyclohexene; or (c) a combination of a and b; and (2) from 55 to 71 mole percent of polymer units ded from ethylene and / or said α-olefin comprising ethylene, or ethylene and at least one of propylene, 4-methyl-1-pentene, butene-1 , hexane-1 or octene-1; and (3) said polymerizable ethylenically unsaturated monomers other than those ded from (1) and (2) are norbornene; and (C) said nucleating agent, if present, Component (C), comprises one or more of talc and mixtures of citric acid and sodium bicarbonate; (D) said additive, if present, Component (D), comprises one or more other thermoplastic polymers, natural gas carbon black, titanium dioxide, graphite, flame retardants and; and (E) said blowing agent, Component (E), is present in a total amount of from 1.0 to 2.5 grams-moles per kilogram (based on the combined weight of Components A and B), and comprising one or more of sulfur hexafluoride (SFß), water, 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-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-125), difiuoromethane (HFC-32), perfluoroethane, 2,2, -difluoropropane, 1, 1 1-trifluoropropane, perfluoropropane, 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-dicyoro-2,2,2-trifluoroethane (HCFC-123) and 1-chloro-1, 2,2,2-tetrafluoroethane (HCFC-124), trichloromonofluoromethane (CFC-11) ), dichlorodifluoromethane (CFC-12), trichloro-trifluoroethane (CFC-13), dichlorotetrafluoroethane (CFC-14), chlorheptafluoropropane, dichlorohexafluoropropane, azodicarbonamide, azodiisobutyronitrile, benzenesulfonhydrazide, 4,4-oxybenzene, sulfonyl-semicarbazide, p-toluene- Sulfonyl semi-carbazide, barium azodicarboxylate, N, N'-dimethyl-N, N'-dinitrosotero-eftalamide, trihydrazino triazine and mixtures of citric acid and sodium bicarbonate. The process according to claim 18, characterized in that said alkenyl monomer, Component (A), is styrene, said substantially random interpolymer, Component B, is an ethylene / styrene copolymer 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), 1,1,1,1-tetrafluoroethane (HFC-1 34a), 1,1, 2,2-tetrafluoroethane (HFC-1 34), ethyl chloride, 1-chloro-1,1-difluoroethane (HCFC-142b) or chlorodifluoromethane (HCFC-22). The process according to claim 18, characterized in that said alkenyl aromatic monomer, Component (A), is styrene, 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 dioxide of carbon, ethane, propane, n-butane, isobutane, n-pentane, isopentane, neopentane, Cyclopentane, ethanol, 1,1-difluoroethane (HFC-1 52a), 1,1,1,2-tetrafluoroethane (HFC-1 34a), 1,1, 2,2-tetrafluoroethane (HFC-134), ethyl chloride , 1-chloro-1, 1-difluoroethane (HCFC-142b) or chlorodifluoromethane (HCFC-22). twenty-one . A closed cell alkenyl aromatic polymer foam having increased heat distortion temperature, comprising; (A) from 80 to 98 weight percent (based on the combined weight of Components A and B) of one or more alkenyl aromatic polymers and wherein at least one of said alkenyl aromatic polymers has a molecular weight ( Mw) from 100,000 to 500,000; and (B) from 2 to 20 weight percent (based on the combined weight of Components A and B) of one or more substantially random interpolymers having a 12 from 0.1 to 1000 g / 10 min, one Mw / Mn, from 1.5 to 20; who understands; (1) from 21 to 65 mole percent of the polymer units derived from: (a) at least one vinyl or vinylidene aromatic monomer, or (b) at least one aliphatic or cycloaliphatic vinylidene or hidden cycloaliphatic monomer, or (c) a combination of at least one aromatic vinyl or vinylidene monomer and at least one aliphatic or cycloaliphatic vinyl monomer or hidden cycloaliphatic, and (2) from 35 to 79 molar percent polymer units derived from at least one one of ethylene and / or α-olefin of C3-20; and (3) from 0 to 20 mole percent of polymer units derived from one or more polymerizable ethylenically unsaturated monomers other than those derived from (1) and (2); and (C) optionally, one or more nucleating agents; and (D) optionally, one more different additives; and (E) one or more blowing agents present in a total amount of 0.2 to 5.0 grams-moles per kilogram (based on the combined weight of Components A and B); wherein the heat distortion temperature of said foam is increased by about 2 ° C or more relative to a corresponding foam without the substantially random interpolymer. 22. The foam according to claim 21, characterized in that said foam has a thickness of 0.95 cm or more and wherein (A) in the Component (A), said at least aromatic alkenyl polymer has more than 50 weight percent of units alkenyl aromatic monomers and has a molecular weight (Mw) of from 120,000 to 350,000 and is present in an amount of from 85 to 97 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, from 1 .8 to 10; it is present in an amount of from 3 to 15 percent by weight (based on the combined weight of components A and B); and comprises (1) from 29 to 52 mole percent of polymer units derived from; (a) said vinylidene or vinyl aromatic monomer represented by the following formula: A »l c = CH wherein R 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. substitutes selected from the group consisting of halo, C? - alkyl, and C4 haloalkyl; or (b) said aliphatic vinylidene or aesthetically hidden cycloaliphatic vinylidene monomer is represented by the following general formula: A '10 R' - C = C (R2) 2 wherein A1 is a sterically bulky aliphatic or cycloaliphatic substitute of up to 20 carbons, R1 is selected from the group of radicals consisting of radicals With hydrogen and alkyl containing from 1 to 4 carbon atoms, preferably hydrogen and methyl, each R 2 independently is selected from the group of radicals consisting of Hydrogen and alkyl containing from 1 to 4 carbon atoms, preferably hydrogen or methyl; or alternatively R1 and A1 together form a ring system; or (c) a combination of a and b; and 25 (2) from 48 to 71 mole percent of polymer units derived from ethylene and / or said α-olefin comprising at least one of propylene, 4-methyl-1-pentene, butene-1, hexane-1 or octene-1.; and (3) said polymerizable ethylenically unsaturated monomers other than those derived from (1) and (2) comprise norbornene or a norbornene substituted with C6-? o aryl or a C1.10 alkyl; Y (C) said nucleating agent, if present, Component (C), comprises one or more of calcium carbonate, talc, clay, silica, barium stearate, diatomaceous earth, mixtures of citric acid and sodium bicarbonate; Y (D) said additive, if present, Component (D), comprises one or more of the inorganic fillers, pigments, antioxidants, acid cleaners, ultraviolet light absorbers, antistatic agents, other thermoplastic polymers, flame retardants, auxiliary agents, processing, extrusion auxiliaries; and (E) said spreading 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 the inorganic blowing agents, organic blowing agents and / or chemical blowing agents. distortion temperature of said foam is increased by 3 ° C or more relative to a corresponding foam without the substantially random interpolymer. 23. The foam according to claim 21, characterized in that said foam has a thickness of 2.5 cm or more and wherein; (A) in Component (A), said at least alkenyl aromatic polymer has more than 70 weight percent aromatic alkenyl monomer units, has a molecular weight (Mw) of from 30,000 to 325,000, a molecular weight, (Mw / Mn) from 2 to 7, and is present in an amount of from 90 to 95 weight percent (based on the combined weight of 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 present in an amount of from 5 to 10 weight percent (based on the combined weight of components A and B); and comprises (1) from 29 to 45 mole percent of polymer units derived from; (a) said vinyl aromatic monomer comprising styrene, α-methyl styrene, ortho-, meta- and para-methylstyrene, and halogenated styrene rings, or (b) said vinyl or vinylidene, aliphatic or cycloaliphatic monomers comprising -ethylidene-2-norbornene or 1-vinylcyclohexene, 3-vinylcyclohexene and 4-vinylcyclohexene; or (c) a combination of a and b; and (2) from 55 to 71 mole percent of polymer units derived from ethylene and / or said α-olefin comprising ethylene, or ethylene and at least one of propylene, 4-methyl-1-pentene, butene-1 , hexane-1 or octene-1; and (3) said polymerizable ethylenically unsaturated monomers other than those derived from (1) and (2) are norbornene; and (C) said nucleating agent, if present, Component (C), comprises one or more of talc and mixtures of citric acid and sodium bicarbonate; (D) said additive, if present, Component (D), comprises one or more of natural gas carbon black, other thermoplastic polymers, titanium dioxide, graphite, flame retardants; Y . (E) said blowing agent, Component (E), is present in a total amount of from 1.0 to 2.5 grams-moles per kilogram (based on the combined weight of Components A and B), and comprising one or more than nitrogen, sulfur hexafluoride (SF6), argon, carbon dioxide, water, air and helium, methane, ethane, propane, n-butane, isobutane, n-pentane, isopentane, neopentane, methanol, ethanol, n-propanol and isopropanol, methyl fluoride, perfluoromethane, ethyl fluoride, 1,1-difluoroethane (HFC- 152a), 1,1,2,2-tetrafluoroethane (HFC-134), 1,1,1,3,3-pentafluoropropane, fluoroethane (HFC-161), 1,1,1-trifluoroethane (HFC-143a), 1, 1, 1, 2-tetrafluoroethane (HFC-134a), pentafluoroethane (HFC-125), difluoromethane (HFC-32), perfluoroethane, 2,2, -difluoropropane, 1,1-trifluoropropane, perfluoropropane, 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), trichloro-trifluoroethane (CFC-113), dichlorotetrafluoroethane (CFC-114), chloroheptaf luoropropane, dichlorohexafluoro propane, azodicarbonamide, azodiisobutyronitrile, benzenesulfonhydrazide, 4,4-oxibenzene , sulfonyl-semicarbazide, p-toluene-sulphonyl semi-carbazide, barium azodicarboxylate, N, N'-dimethyl-N, N'-dinitrosotero-phthalamide, trihydrazino triazine and mixtures of citric acid and sodium bicarbonate; and wherein the heat distortion temperature of said foam is increased by 5 ° C or more relative to a corresponding foam without the substantially random interpolymer. 24. The foam according to claim 23, characterized in that said alkenyl aromatic polymer, component (A), is polystyrene, said substantially random interpolymer Component B is an ethylene / styrene copolymer and the blowing agent, Component (E), is one or more than carbon dioxide, n-butane, isobutane, n-pentane, isopentane, neopentane, ethanol, 1,1-difluoroethane (HFC-152a), 1,1,2,2-tetrafluoroethane (HFC-134), 1, 1, 1, 2-tetrafluoroethane (HFC-134a), ethyl chloride, 1-chloro-1,1-difluoroethane (HCFC-142b), or chlorodifluoromethane (HCFC-22). The foam according to claim 23, characterized in that said alkenyl aromatic polymer, Component (A), is polystyrene, 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 dioxide carbon, n-butane, isobutane, n-pentane, isopentane, neopentane, ethanol, 1,1-difluoroethane (HFC-152a), 1,1, 1,2-tetrafluoroethane (HFC-134a), ethyl chloride, -chloro-1,1-difluoroethane (HCFC-142b) 1,1, 2,2-tetrafluoroethane (HFC-134), or chlorodifluoromethane (HCFC-22). 26. The foam according to claim 21, having a density of from 10 to 150 kilograms per cubic meter (kg / m3) and a cell size of 0.05 to 5.0 millimeters. 27. The foam according to claim 21, having a density of from 10 to 70 kg / m3 and a cell size of 0.1 to 1.5 millimeters. 28. The foam according to claim 21, characterized in that the alkenyl aromatic polymer material comprises more than 70 weight percent aromatic monomeric alkenyl units, the substantially random interopolymer is incorporated to increase the heat distortion temperature by 5 ° C or more relative to a corresponding foam without the substantially random interpolymer, and the foam has a density of 10 to 150 kg / cm 3 and a cell size of 0.05 to 5.0 millimeters. The foam according to claim 21, characterized in that the aromatic alkenyl polymeric material comprises more than 70 weight percent aromatic alkenyl monomer units, the substantially random interopolymer is for increasing the heat distortion temperature by 5 ° C or more relative to a corresponding foam without the substantially random interpolymer, and the foam has a density of from 10 to 70 kg / cm 3 and a cell size of 0.1 to 1.5 millimeters.