MXPA00001926A - Condensation copolymers having surpressed crystallinity - Google Patents

Abstract

Condensation copolymers are disclosed which are polymerized from a first monomer which is capable of polymerization by condensation polymerization, e.g., ring opening lactone polymerization, and a second monomer which is effective to suppress the crystallization of the copolymer. It is disclosed that suppression of the crystallization can provide enhanced mechanical properties in films made from the copolymers. As a result, films prepared from the copolymers of the present invention can have properties rendering them suitable for use as biodegradable trash bags as well as for other uses.

Description

CONDENSATION COPYCYMERS WITH DELETED CRYSTALLINITY FIELD OF THE INVENTION The present invention relates to condensation copolymers, polyesters, having crystallinity removed which can make them suitable for use, for example, in the manufacture of biodegradable films for garbage bags.

BACKGROUND OF THE INVENTION Current environmental aspects have generated interest in the use of biodegradable plastics for disposable articles such as, for example, garbage bags, packaging materials, food utensils and the like. A series of biodegradable polymers have been proposed for such uses, usually these polymers include condensation polymers such as, for example, polyesters, polyester amides, polymers formed by ring opening polymerization, eg, lactone polymerizations, Q lactam and lactam, polyhydroxyalkonatides, polylactic acid and natural polymers such as polysaccharides, for example, cellulose, starch and soy derivatives. As used herein, the term "Biodegradable", as defined in ASTM D-883, is made with reference to degradable polymers in which degradation results from the action of natural microorganisms such as, for example, bacteria, fungi and algae. Biodegradability can be checked, for example, by the production of CO2 and the associated reduction in mechanical properties such as tensile strength and percent elongation at break. Other details are known to those skilled in the art. Although many polymers such as those described above are highly effective in terms of their biodegradability, they often exhibit inferior mechanical performance that has impeded their commercial viability. More specifically, when they are converted into film by extrusion of blown film, for example, biodegradable polymers usually do not have good machine direction ("MD") Elmendorf tear strength as measured by ASTM D-1922, transverse direction ("TD ") Tensile strength as measured by ASTM D-1822, impact strength of a falling dart measured by ASTM D-1709, MD and TD secant module measured by ASTM D-882, and drilling resistance as measured by the test Union Carbide method C-68-L. On the other hand, when biodegradable polymers are modified to improve their mechanical properties, their biodegradability is often affected. As used herein, the terms "condensation polymerization" and "polycondensation" mean: (i) a polymerization reaction in which two or more molecules combine with the generation of water, alcohol or other simple substances as by-products; and (ii) the polymerization of the monomers, for example, ester and amide monomers, formed by ring-opening polymerization, for example, lactones, lactides and lactams that do not generate water, alcohol or other simple substances as by-products. Frequently condensation polymers suitable for use as biodegradable materials are in i-crystalline form, for example, more than about 30% by weight, often greater than about 50% by weight and more frequently greater than about 70% by weight. crystalline weight. The complete crystallization of polymers is often a slow process that takes minutes, hours or days to complete. When crystallization is desired, the temperature is maintained above the glass transition temperature ("Tg") and below the crystalline melting point for a sufficient time to allow the polymer molecules to be arranged in crystal lattices. This process is also known in the art as "annealing." If the crystallinity of the polymer becomes too high, the molded polymer article may not have sufficient rigidity to be possible in a common end use such as garbage bags, tarred film, molded parts and the like.

Accordingly, improved condensation polymers having better mechanical properties and retaining their biodegradable characteristics are desired.

SUMMARY OF THE INVENTION The improved condensation polymers are obtained by the present invention. The improvement of the present invention is directed to the use of the comonomers in the condensation polymerization which are effective to eliminate the crystallinity of the copolymers. Without adhering to any specific theory, it is considered that the removal of the crystallinity can make improvements in the mechanical properties of the films prepared from the copolymers compared to the copolymers prepared without the crystallinity-eliminating monomers. According to the present invention, the elimination of the crystallinity can be evidenced by one more factors. For example, the removal of the crystallinity may be evident by a reduction in the crystallization temperature of the copolymer, or by a reduction in the crystallization rate of the copolymer, or by a reduction in the melting temperature of the polymer or by a reduction in the crystallinity of the copolymer. As used herein, the term "crystallization temperature" means the temperature at which the formation of the crystalline phase occurs; the term "crystallization rate" means the rate at which the formation of the crystalline phase occurs; the term "melt temperature" means the freezing point and the term "crystallinity" means the degree of crystallinity of the polymer. The crystallization properties of the polymers can be readily determined by those skilled in the art, such as for example by differential scanning calorimetry ("DSC").

DETAILED DESCRIPTION OF THE INVENTION The first monomer suitable for use in accordance with the present invention can be any monomer that is polymerizable by condensation polymerization. The first monomer may be ethylenically unsaturated or otherwise may not have ethylenic unsaturation. The molecular structure of the first monomer is not crucial for the present invention and can be straight, for example, normal, alkyl or branched, cyclic or aromatic. Preferably, the first monomer has functional groups selected from the group consisting of steres, ethers, alcohols, acids, amines, amides, acid halides, isocyanates and mixtures thereof as can be determined by those skilled in the art. In addition, the first monomer may be composed of a single molecular unit, an oligomer or a prepolymer and may have a molecular weight of, typically, from about 62 to 12,000 grams per gram mol ("g / gmol"), more commonly , from about 62 to 10,000 g / gmol.

Unless stated otherwise, as used herein, the term "molecular weight" means the numerical average molecular weight. Techniques for determining numerical average molecular weight are known to those skilled in the art. One of these techniques is gel permeation chromatography ("GPC"). In one aspect of the present invention, the first monomer consists of one or more compounds that can be polymerized or copolymerized to form aliphatic polyesters or polyester amides or other condensation polymers. Examples of these polymers include, for example, polyesters prepared from the reaction of C2-C6 diols, for example, ethylene glycol, diethylene glycol, butanedi, neopentyl glycol, hexanediol with dicarboxylic acids as they may be, but are not limited a, succinic, glutaric or adipic acid; copolyesters of polymers based on terephthalic acid with dicarboxylic acids and diols and polyester / amides of the reaction of caprolactam with dicarboxylic acids and diols. Suitable hydroxy acids include, for example, α-hydroxybutyric acid, hydroxyisobutyric acid, oc-hydroxyvaleric acid, α-hydroxyisovaleric acid, hydroxycaproic acid, α-hydroxyisocaphoic acid, α-hydroxy-α-Gth-butyric acid, α-hydroxy-β-m-ethylvaleric acid, hydroxyheptanoic acid, hydroxy-octanoic acid, hydroxy-decaic acid, α-hydroxymyric acid, and -hydroxystearic acid or its intermolecular cyclic esters or combinations thereof. In another aspect of the present invention, the first monomer consists of cyclic monomers that are polymerized by ring opening polymerization. Common to these monomers are cyclic esters such as lactides, glycolides, lactones and cyclic carbonates. In one aspect of the present invention, the cyclic monomers include those having the formulas: where X = nil, -0-, or -0-C = 0; Z = 1-3; Y = 1-4; R? ~ R4 = H-, -CH3, C2-C? 6 alkyl group of C2-C? 6, -C (CH3), or H0CH2-, and where all R are independent in each unit of independent carbon yoz between yes; or Q. ^ -rv .. 1 -C R, where R1-R4 = H-, -CH3, C2-C6 alkyl group, or H0CH2-, and where all R are independent from each other.

Examples of the lactones described above are, but are not limited to, e-caprolactone, t-butyl caprolactone, z-enantholactone, deltavalerolactones, monoalkyl-delta-valerolactones, for example, monoethyl-, monoethyl-, monohexyl- deltavalerolactones and the like; nonalkyl, dialkyl and trialkyl-epsilon-caprolactones, for example, monomethyl-, monothyl-, monohexyl-, dimethyl-, di-n-propyl-, di-n-hexyl-, trimethyl-, triethyl-, tri-n- epsilon-caprolactones, -nonyl-oxepan-2-one, 4,4,6- or 4,6,6-trimethyl-oxepan-2-one, -hydroxymethyl-oxepan-2-one, and the like; beta-lactones, for example, beta-propiolactone, beta-butyrolactone, gamma-lactones, for example, gamma-butyrolactone or divalolactone, dilactones, for example, lactide, dilactides, glycolides, for example ^ tetramethyl glycolides and the like, ketodioxanones, for example, 1,4-dioxan-2-one, 1,5-dioxepan-2-one, and the like. The lactones may consist of the optically pure isomers or two or more optically different isomers or may consist of mixtures of isomers. In addition to the cyclic carbonates of the formula: where X = nil, -O; Z = 1-3; Y = 1-3; R-R4 = H-, -CH3, C-C6 alkyl group or HOCH2-, and where all R are independent in each carbon unit and or z independent of each other, can be used as comonomers with the lactones of this invention. Examples of the suitable cyclic carbonates are ethylene carbonate, 3-ethyl-3-hydroxymethyl trimethylene carbonate, propylene carbonate, tri ethylene carbonate, trimethylolpropane monocarbonate, 4,6-dimethyl-l-3-propylene carbonate, 2, 2-dimethyl trimethylene carbonate and 1,3-dioxepan-2-one carbonate. The e-caprolactone and its derivatives and other 7-membered lactones in the ring are especially preferred for use as the first monomers according to the present invention. Examples of the common cyclic ester polymers and their (co) polymers resulting from the polymerization of the aforementioned monomers include: poly (L-lactide); poly (D, L-lactide); poly (mesochoctide); poly (glycolide); poly (trimethylene carbonate); poly (epsilon-caprolactone); poly (L-lactide-co-D, L-lactide); poly (L-lactide-co-esolactide); poly (L-lactide-co-glycolide); poly (L-lactide-co-trimethylene carbonate); poly (L-lactide-co-epsilon-caprolactone); poly (D, L-lactide-co-mesochoctide); poly (D, L-lactide-co-glycolide); poly (D, L-lactide-co-trimethylene carbonate); poly (D, L-lactide-co-epsilon-caprolactone); poly (meso-lactide-co-glycolide); poly (meso-lactide-co-tri-ethylenecarbonates); poly (esolacturo-co-epsilon-caprolactone); poly (glycolide-co-trimethylene carbonate); poly (glycolide-co-epsilon-caprolactone). ordinarily, the amount of the first monomer used in the copolymers of the present invention is from about 50 to 99% by weight, preferably from about 60 to 98% by weight and more preferably from about 85 to 95% by weight, based on the total weight of the monomers in the copolymer. Monomers suitable for use as the first monomer in the copolymers of the present invention are available commercially. The second monomer suitable for use in the preparation of the copolymers of the present invention includes any of the monomers that are functional to remove the crystallinity of the copolymer. Preferably, the second monomer is amorphous. As used in the present invention, the term "amorphous" means that the monomer is primarily amorphous, ie, more than 50% amorphous, preferably greater than 70% amorphous and more preferably greater than 90% amorphous, determined, for example, DSC measuring the enthalpy of fusion. The second monomer may be ethylenically unsaturated or otherwise may not have ethylenic unsaturation. The molecular structure of the second monomer is not crucial for the present invention and can be straight, for example, normal, alkyl or branched, cyclic or aromatic. In a preferred aspect of the invention, the second monomer is a branched ester. Preferably, the second monomer has a functional group selected from the group consisting of esters, ethers, alcohols, acids, amides, acid halides and mixtures thereof. In addition, the second monomer can be composed of a single molecular unit, an oligomer or a prepolymer and can have a molecular weight usually from about 62 to 12,000 g / gmol, more commonly from about 62 to 10,000 g / gmol. Moreover, the second monomer may comprise a derivatization of the first monomer, for example, a branched caprolactone such as, for example, t-butyl lactone. In the polymerization of the first monomer, the second monomer is usually used as an initiator, for example to initiate the ring opening of the cyclic lactone monomers. Usually, the removal in the crystallinity produced by the second monomer will be evidenced by one or more of the following factors: (i) a reduction in the crystallization temperature of the copolymer of at least 2 ° C, preferably at least 4 ° C C and more preferably at least 6 ° C, compared to a homopolymer of the first monomer or a copolymer of the first monomer and another monomer that is not effective in removing the crystallinity, or (ii) a reduction in the crystallinity of the copolymer. Usually, according to the present invention, the crystallinity will be reduced by at least 2%, preferably by at least 6% and most preferably by at least 8% compared to the crystallinity of a homopolymer of the first monomer or a copolymer of the first monomer and another monomer that is not effective in suppressing crystallinity. The crystallinity can be determined by DSC, measuring the enthalpy of fusion. In one aspect of the present invention, the second monomer is effective to create amorphous regions in the copolymer. For example, if the second monomer is a branched version of the first monomer, it will generally not co-crystallize with the first monomer, it will thus break the crystallization of the first monomer by increasing the amorphous region, decreasing the crystallinity of the copolymer. If the second "monomer" is a non-crystallizable oligomer, the net crystallinity of the copolymer will be reduced to a level that can improve the stiffness of the molded polymer. In one aspect of the present invention, the second monomer is effective to introduce branching into the polymer, i.e., chains pendant from the main chain of the copolymer. Preferably, the branching is introduced as short chains in the main structure of the copolymer. As used herein, the term "short chain branching" means hydrocarbon branching, for example, alkyl groups in the polymer backbone, which are preferably Ci-Cie alkyl groups, ending in a free end. unreacted, for example, methyl, propyl, t-butyl. Branching with short chains can be introduced into the polymer backbone, for example, using branched difunctional initiators obtained by polymerizing a linear or branched dicarboxylic acid with a linear or branched diol initiator, so that at least the acid or diol is branched . Suitable dicarboxylic acids are of the formula: where Y = 0 to 12; Rx and R2 = H-, -CH3 or alkyl group of C2-C ?, and where all R are independent of each other and each carbon unit. Examples of the dicarboxylic acids are succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, dodecandioic acid and 2-ethyl-2-methylsuccinic acid. In addition to the aliphatic dicarboxylic acids described above, it is also possible to use aromatic dicarboxylic acids such as, but not limited to, phthalic acid, isophthalic acid, and terephthalic acid.

Suitable diol initiators are of the formula: where X = nil, -Q-; a = 1 to 6; b = or a 10; c = ni, Ci-Ciß [sicj; and R1-R4 = H-, -CH3, or C2-C16 alkyl group, and where all R are independent of each other and each carbon unit. Examples of the diols are, but are not limited to, ethylene glycol, diethylene glycol / 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,10-decanediol, 1,12-dodecanediol, 1 , 2-dekanediol, 1,2-dodecanediol, 1,2-hexadecanediol, neopentyl glycol, 3-methyl-1, 5-pentanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1, 3-propanediol, 2-ethyl-3-butyl-l, 3-propanediol, 2-ethyl-l, 6-hexanediol. Of these, the adipate of 2-butyl-2-ethyl-1, 3-propans, prepared from the reaction of 2-butyl-2-ethyl-1,3-propanediol ("BEPD") and adipic acid is preferred. Other methods of introducing short chain branching include the reaction of branched or long chain 1,2-diol with the mono ero-caprolactone and then the transesterification with the diester of the dicarboxylic acid, for example, the transesterifation of a caprolactone oligomer initiated with BEPD with dimethyl adipate, or the reaction of a caprolactone oligomer initiated with BEPD with adipoyl chloride, or the reaction of a caprolactone oligomer initiated by BEPD with a diisocyanate, i.e., HDI or MDI, or by reacting branched lactones with lactones unbranched, for example, the copolymer of t-butylcaprolactone and e-caprolactone. As an alternative or in addition to the branched monomers, polymerized, the branched polymers may be combined in linear polymers of other molecules to provide short chain branching. The amount of the second monomer suitable for use in the preparation of the copolymers of the present invention is effective in removing the. crystallinity of the copolymer. The amount is usually from about 1 to 50% by weight, preferably from about 5 to 35% by weight and more preferably from about 9 to 20% by weight, based on the total weight of the monomers used to prepare the copolymer. The optimum level of the second monomer will depend on the specific structure of the second monomer and can be determined by those skilled in the art. In the preparation of the copolymers of the present invention it is possible to use one or more monomers of the first group of monomers or of the second group of monomers. In addition, it is also possible to use other monomers in addition to the first monomer and the second monomer. Such other monomers can be introduced, for example, to impart certain desired properties to the copolymer. The other particular monomers are not crucial to the present invention but may include, for example, monomers such as dialcohols, for example, ethylene glycol, 1,4-butanediol, 1,3-propanediol, 1,6-hexanediol, diethylene glycol, etc. , dicarboxylic acids, for example, oxalic acid, succinic acid, adipic acid, amino alcohols, for example, ethanolamine, propanolamine, amino carboxylic acids, for example, aminocaproic acid, and the like. In addition, it is possible to use other monomers that are normally used to prepare traditional non-biodegradable polymers such as polyethylene (including low density polyethylene, linear low density polyethylene and high density polyethylene), ethylene-vinyl acetate copolymers, copolymers ethylene-acrylic acid, polyvinyl chloride, polystyrenes, chlorinated polyethylenes, ethylene propylene copolymers, acrylic acid copolymers, polyvinylacetal copolymers, polyamines, polyethylene terephthalates, phenolic resins and urethanes. In addition to other monomers, the copolymers of the present invention may be combined and / or reacted with other polymers to provide the desired characteristics. For example, the copolymers of the present invention can be extruded with other polymers such as, for example, polysaccharides, for example starch, cellulosics, quitanas and the like. More details of these mixed polymer compositions are known to those skilled in the art. See, for example, U.S. Patent No. 5,095,054 which is directed to thermoplastic polymer compositions comprising destructurized starch and other polymers, U.S. Patent No. 5,540,929 which is directed to aliphatic polyester grafted polysaccharides. Usually, the amount of these other monomers, when used in the copolymers of the present invention, is from about 1 to 90% by weight. Usually, when the copolymers of the present invention are mixed or reacted with other polymers the amount of the other polymer is usually from about 0 to 70% by weight, and preferably from about 20 to 60% by weight and greater preferably from about 30 to 40% by weight, based on the total weight of the mixed polymer composition. Another aspect of the present invention is directed to the introduction of branching of long chains in the polymer backbone. In this aspect of the invention, the long chain branching can be incorporated into the polymer backbone or the long chain branching polymers can be combined with the copolymers to improve processability. As used herein, the term "long chain branching" means hydrocarbon branches, for example, alkyl groups in the main chain terminating in more than two reactive end groups that give rise to the preparation of non-linear polymers. Examples of polymers with long chain branching are, but not limited to, polymers of e-caprolactone with multifunctional initiators such as trimethylol propane, pentaerythritol, dipentaerythritol and other molecules with multiple hydroxyl groups or other reactive groups. The improved processing capacity of the copolymers of the present invention can be measured, for example, by determining their index values of the Relaxation Spectrum (RSI). As used herein, the terms "Relaxation Spectrum Index" and "RSI" mean the amplitude of the distribution of molecular relaxations in the molten state calculated from dynamic oscillatory shear tests run in a frequency range from 0.1 to 100 1 / sec. The R.SI is a sensitive indicator of the molecular structure, such as the branching of long chains, which causes a long relaxation time behavior in the molten state. Other details related to the RSI are known to those skilled in the art. See, for example, J. M. Dealy and K. F. issbrun, Met Rheology and Its Role in Plastics Processing, Van Nostrand Reinhold, 1990, p. 269-297 and S. H. Wasser an, J. Rheology, vol. 39, pp. 601-625 (1995). The processes used to prepare the copolymers of the present invention are not crucial. The polymer of the 1Q present invention can be prepared by bulk polymerization, suspension polymerization, extruder polymerization or solution. The polymerization can be carried out, for example, in the presence of an inert organic carrier, normally liquid as can be, for example, aromatic hydrocarbons, for example, benzene, toluene, xylene, ethylbenzene and the like; oxygenated organic compounds such as anisole, dimethyl and ethylene glycol diethyl esters; normally liquid hydrocarbons including saturated, cyclic, and cyclic alkyl-substituted saturated hydrocarbons such as hexane, heptane, cyclohexane, decahydronaphthelene, and the like. The polymerization process can be carried out in a batch, semi-continuous or continuous form. The monomers and catalysts can be mixed in any order according to the known polymerization techniques. Thus, the catalyst can be added to a comonomeric reagent. Then, the comonomer containing the catalyst can be mixed with another comonomer. In the alternative, the comonomeric reagents can be mixed together. The catalyst can then be added to the reaction mixture. If desired, the catalyst can be dissolved or suspended in a normally liquid, inert organic carrier. If desired, the monomer reagents as a solution or suspension in an inert organic vehicle can be added to the catalyst, catalyst solution or catalyst suspension. Still further, the catalyst and the comonomeric reagents can be added at the same time to a reaction vessel. The reaction vessel may be equipped with a traditional heat exchanger and / or mixing device. The reaction vessel can be any equipment normally used in the polymer manufacturing art. A suitable container, for example, is a stainless steel container. If used, a plasticizer or a solvent may be mixed in the polymer to help separate the polymeric material from the reaction vessel. Polymerization reactions are usually carried out at a temperature of from about 70 to 250 ° C. preferably from about 100 to 22Q ° C, during a reaction time from about 3 minutes to 24 hours, preferably from about 5 to 10 hours. The reaction pressure is not crucial for the present invention. The specific catalyst used in the polymerization is not crucial and can be determined by those skilled in the art. However, a preferred catalyst for the polymerization of caprolactone with adipate BEPD is tin carboxylate. The catalyst and the initiator can be combined in the same molecules, for example, an aluminum alkoxide.

In addition to the monomers it is possible to add other ingredients, such as plasticizers, for example, epoxidized soy bean oil, epoxidized flaxseed oil, triethyl citrate, acetitriethyl citrate, tri-n-butyl citrate, acetyl citrate citrate. butyl, acetyltri-n-hexyl citrate, glycerin, diethyl phthalate, dioctyl phthalate, antiblock, for example, stearamide, behenamide, oleoamide, eruca ida, stearilerucamide, erusilerucamide, oleilpal itamide, stearyltearamide, erusyltearamide, N, N'-ethylene-isostearamide, N, N'-ethylenebisoleamide, talc, calcium carbonate, kaolin clays, molecular sieves and other particulate materials, stabilizers, compatibilizers, nucleating agents, pigments, etc. Typically, the total amount of these other ingredients is in the range of from about 0.01 to 10% by weight, based on the total weight of the copolymer composition. More details related to the selection and quantity of these additives are known to those skilled in the art. The copolymers produced according to the present invention usually have a melting point from about 50 to 240 ° C, preferably from about 52 to 120 ° C, and a Tg from about -120 to 120 ° C and preferably from about -60 to 60 ° C. Copolymers typically have a melt flow of from about 0.1 to 7, preferably from about 0.2 to 2.5 and more preferably from 0.5 to 2. As used herein, the term "Melt Flow" means grams. of material flowing through a nozzle in 10 minutes at 125 ° C / 2.16 kilograms ("kg") as described in ASTM D-1238. The density of the copolymers is usually in the range from about 1.00 to 1.50 grams per cubic centimeter ("g / cc") and preferably from about 1.0 to 1.20 g / cc. Preferably, the addition of amorphous blocks or branching (short and / or long chain) will reduce the density of the copolymer relative to the homopolymer in the solid state. The reduction in density can give rise to better polymer stiffness properties. Preferably, the copolymers of the present invention have a density reduction of at least 0.004 g / cc and more preferably from about 0.004 to 0.040 g / cc relative to the homopolymer of the first monomer (exclusive of the initiator.) common, the copolymers of the present invention have a weight average molecular weight (Mw) of from about 500 to 800,000 grams / gram mol, and preferably from about 50,000 to 500,000 grams / gram mol. Usually the number average molecular weight (Mn) is in the range from about 500 to 700.00 grams / gram mole, preferably from about 30,000 to 500,000 grams / gram mole. The polydispersity index (Mw / Mn) is usually in the range from about 1.3 to 10.

Upon completion of the polymerization reaction, the copolymers can be recovered by any means known to those skilled in the art. Preferably, according to the invention, the copolymer is transported in its molten state directly to a granulator, extruder or molding machine to produce the desired product. These products can be produced in any manner known to those skilled in the art, such as for example fibers, granules, molded articles, films, sheets and the like. The films containing the copolymer compositions of the present invention can be converted into cast or blown films, sheets, blow molded, injection molded or fiber spun using any process or equipment known to those skilled in the art. Normally the films have a thickness from about 0.5 to 2 mils preferably from about 0.6 to 1.7 mils, and more preferably from about 0.7 to 1.5 mils. The mechanical properties mentioned herein are based on a film thickness of 1.0 to 1.3 mils. Typically, the films have an MD tensile strength from about 3000 to 9000 psi, preferably from about 4000 to 8000 psi, with an elongation at MD break of about 250 to 900%, preferably from about 400 to 800%, as measured by ASTM D-882.

Typically, the films have a tensile strength TD from about 2000 to 8000 psi, preferably from about 4000 to 6000 psi, with an elongation at break from about 300 to 1000%, preferably from about 500 to 900%. The shock properties of falling a dart in films is usually in the range from about 20 to 200 grams per 1/1000 inches ("g / mil"), preferably at least 50 g / mil and greater preference in the range from about 50 to 150 g / thousand. The elmendorf MD tearing properties of the films is usually in the range from about 5 to 200 g / mil and preferably in the range from about 15 to 150 g / mil. The tearing properties elmendorf TD of the films usually is in the range from 100 to 700 g / thousand and preferably in the range from about 100 to 700 g / thousand. The MD secant modulus properties of the films are usually in the range of 60,000 to 100,000 psi and preferably in the range of about 30,000 to 80,000 psi. The TD blot module properties of the films are usually in the range of 70,000 to 130,000 psi and preferably in the range of about 30,000 to 80,000 psi. The MD tensile shock properties of films are usually in the range of 400 to 1100 ft.-lbs./in.in. and preferably in the range of about 400 to 1700 ft.-lb./sc. The TD tensile shock properties of the films are usually in the range from 70 to 1100 ft-lb / cu in and preferably in the range from about 200 to 1700 ft-lb / cu [fx. The puncture resistance properties of films are usually in the range of 3 to 50 in-lbs / mil and preferably in the range of about 10 to 50 in-lbs / mil. The copolymers of the present invention can be used in the manufacture of a wide range of products including, for example, sheets, ie, greater than 10 mil thick films, ie less than 10 mil thick, for example , garbage bags, fibers, for example, sutures, fishing lines and non-woven fabrics and molded articles, for example, containers, tools and medical devices such as, for example, staples, clips, pins, prostheses, etc. A particularly preferred end use according to the present invention is to provide compostable films for use as a garbage bag. As defined in ASTM D-883, a compostable plastic is a plastic that undergoes biological degradation during the deformation of compost to produce carbon dioxide, water, inorganic compounds and biomass at a rate consistent with other known compostable materials and leaves no residue visually distinguishable or toxic. Usually, the copolymers of the present invention are practically biodegradable. More specifically, the copolymer compositions are generally biodegradable and can be composted by ASTM D-5338, which is a standard test method for Determination of Aerobic Biodegradation of Plastic Materials under controlled conditions for the formation of compost.

Examples The following examples are provided for illustrative purposes and are not intended to limit the scope of the following claims. The following test procedures were used in the examples.

GPC test procedure The GPC was performed on an HPCL Waters 590 unit with an LC-241 autosampler, Waters Styragel HR.-1, HR-3, HR-4, HR.-4E, HR-5E, a differential refractometer detector ERMA ERC-7510 connected to a VG data system, using tetrahydrofuran (stabilized with BHT), as the solvent, disposable 0.45u PTFE filters (for sample preparation) and a nylon 66 filter of 0.45u ( to degas the mobile phase). The unit was calibrated using polystyrene standards in the molecular weight range of 162 to 1,800,000. The operational parameters were; Flow 1.0 ml / min Run time 65 minutes Injection size 200 ul Temperatures Detector 35c [sic] Ambient columns Tn or 'nr environment The concentration of the sample was 0.5% by weight / volume.

Melt flow The melt flow of the polymers was determined using ASTM D-1238. The determinations were made at a temperature of 125 ° C and a pressure of 2.16 kg.

Density The density of the polymers was determined using ASTM D-1505, Density per Gradient Column.

Film properties Except for the puncture resistance, the properties of the film were measured using the appropriate ASTM test procedure, for example, ASTM D-1709 for the shock resistance by the falling dart 2 « (Also known herein as "dart drop.) The puncture resistance of the film was measured using the Union Carbide Corporations WC-68-L method, and is a test procedure known to those skilled in the art ( also known herein as "puncture resistance"). Puncture resistance is defined as the force required to break a test sample and the energy absorbed by the film during the breakdown, as opposed to the descending dart method. , which measures the high-speed shock, the resistance, the drilling uses a piston in slow motion moving at a crosshead speed of 20 inches / minute, an Instron Traction Tester, CVC compression cell (model G-03- 2), integrator, film and piston carrier, weights for calibration and micrometer Five samples of 6 by 6 inches of each film are prepared and conditioned for 40 hours at 23 ± 2 ° C and relative humidity of 50 ± 5%. The thickness of each film is measured in the center to the nearest 0.0001 inch and mounted on the compression cell so that the piston will puncture the center of the film. The piston is placed 8 inches above the compression cell and will have a downward stroke of 6 inches. The load in pounds needed to break the samples is recorded and the results reported as in-Ibs / thousand.

Differential Scanning Calorimetry (DSC) The DSC for the polymers were measured in a helium atmosphere from -100 ° C to 85 ° C at a rate of 10 ° C / minute. Instead of the properties of the film, the effect of crystalline removal by addition of an amorphous block or short chain branching was determined using DSC. The effect is shown with a depression of the crystallization temperature (Te), and in a second heat depression of the melting point (Tm2) and a decrease in the crystallinity as measured by a reduction in the heat of fusion (? Hf) . relaxation spectrum index The R.SI of the polymer is determined by first subjecting the polymer to a shear strain and measuring its response to deformation using a rheometer. As is known in the art, based on the response of the polymer and the mechanics and geometry of the used rheometer, the relaxation module G (t) or the dynamic modules G '(vi) and G "() were determined as functions of the time or frequency.

Biodegradability ASTM D-5338, which is a standard test method for the Determination of Aerobic Biodegradation of Plastic Materials under Controlled Conditions for Compost Formation, was used to determine the biodegradability of the co-polymer. In the examples the following ingredients were used.

TONE® Monomer ECEQ - an e-caprolactone monomer available from Union Carbibe Corporation, Danbury, CT. TONE Folymer P-787 an 80,000 Mn polymer available from Union Carbibe Corporation, Danbury, CT. TONE Polymer P-767 a polymer of 43,000 Mn available from Union Carbibe Corporation, Danbury, CT. TONE Polymer P-300 a polymer of 10,000 Mn available from Union Carbibe Corporation, Danbury, CT.

EXAMPLE 1 PREPARATION OF ADIPATQ MQNOMERS OF BRANDED B ^ .PD Adipates of BEPD in the molecular weight range of 4000 to 21000, determined by GPC, were prepared in a 4-neck resin kettle equipped with a Dean Stark condenser and trap , agitator, nitrogen spray tube and flow meter, and a thermocouple connected to a mantle or heating jacket with controlled temperature. On a molar basis, the reactor was charged with the appropriate amount of BEPD, adipic acid and toluene at 10% by weight as an azeotrope solvent. The azeotrope solvent is included to separate the produced water as a byproduct of the reaction. The reaction was carried out under nitrogen and heated to 140 ° C. After stopping collecting the water in the Dean Stark trap, the temperature was raised in increments of 20 ° C to 220 ° C and held until it was obtained > 95% of the theoretical amount of water that was to be separated. The temperature was reduced to 160 ° C, an adequate amount of a metal carboxylate catalyst was charged, the temperature was raised to a maximum of 220 ° C and the reaction was allowed to continue for 12 to 16 hours. The acidity index was determined and if it was > 4 additional catalyst was added and the reaction was continued until the acid number was > 4. The acidity index and the molecular weight per GPC of the product were determined.

EXAMPLE 2 PREPARATION OF C-QPQLÍMERQS BRAPED BEPD ADIPATE GAPRQLAC-TQNA Caprolactone copolymers / BEPD adipates with molecular weights GPC > 40,000, in a pot of resin with four necks, equipped with a stirrer, nitrogen spray tube and flow meter, a thermocouple connected to an oil bath with controlled temperature and vacuum. On a molar basis, the reactor was charged with a suitable amount of the monomer e-caprolactone and the adipate monomer of BEPD of Example 1. Otherwise, the long chain branching can also be included by addition of 20 to 120 ppm of trimethylol propane. To remove the moisture from the reaction, the reactants are dried in a nitrogen environment at 80 ° C under vacuum. After the waste water was reduced to < 100 ppm, the vacuum was discontinued and the temperature was raised to 120 ° C, charged with an adequate amount of a metal carboxylate catalyst and then the temperature was increased to obtain a temperature of the material > 14Q ° C. The reaction was maintained at the temperature until the percent of residual monomer e-caprolactone was < 1%. The polymer was discharged and converted into granules for extrusion in blown film. The melt index, the GPC molecular weight and the RSI values of the polymer were determined.

EXAMPLE 3 PREPARATION OF BRANCHED MQNÓMERQ SUC-CINATQ As an example of branching incorporation using other branching agents, a branched hexanediol ethyl methyl succinate monomer ("HDEMS") was prepared by reacting 2-ethyl-2-methylsuccinic acid with 1,6-hexanediol . A procedure practically similar to that described in Example 1 was followed, except that the reaction was discontinued when the acid number was about 10. An HDEMS having an acid number of 10.1 and molecular weights GPC of Mn 7628, Mw 22040, M / Mn 2.90 was obtained.

EXAMPLE 4 PREPARATION OF STANDARDS OF SLTCCINATQ HDEM BRANCHED CAPRQLACTONE A procedure practically similar to that described in Example 2 was followed to prepare copolymers of caprolactone / HDEMS. On a molar basis, the reactor was charged with the appropriate amount of monomer e-caprolactone and HDEMS monomer of Example 3. Upon completion of the reaction, the polymer was discharged and converted into extrusions for extrusion into blown film. The fusion index and the molecular weight GPC were determined.

EXAMPLE 5 PREPARATION OF BDO MQNOMERQ ADIPATQ A procedure practically similar to that described in Example 1 was followed to prepare a butanediol adipate monomer ("BDO"), except that the reaction was discontinued when the acid number was <1. 10. A BDO adipate having an acid number of 8.9 and molecular weights GPC of Mn 12000, Mw 38395, Mw / Mn 3.20 was obtained.

EXAMPLE 6 PREPARATION OF ADAPATQ CQPQLÍMERQ BDQ CLAPRQLACTQNA LINEAR A procedure practically similar to that described in Example 2 was followed to prepare a caprolactone / butanediol adipate copolymer. On a molar basis, the reactor was charged with the appropriate amount of the monomer e-caprolactone and butanediol adipate monomer of Example 5. The polymer was discharged and converted into granules for extrusion into blown film. The fusion index and the molecular weight GPC were determined.

EXAMPLE CONTROL 7 PREPARATION OF POLIQL CAPRQLAC-TQNA INITIATED WITH BUTANODIQL A procedure practically similar to that described in Example 2 was followed to prepare a caprolactone polyol initiated by butanediol. A polyol having an acid number of 0.17 and a hydroxyl number of 22.10 was obtained. The molecular weight of the polyol based on its hydroxyl number was 5077.

EXAMPLE CONTROL 8 PREPARATION OF PQLIQL CAPRQLAC-TQNA INITIATED WITH BUTANQDIOL AND ADORQILQ CiORURQ The caprolactone polyol initiated with butanediol of Example 7 was reacted with adipoyl chloride in a 4-neck resin kettle equipped with a Dean Stark condenser and trap, stirrer and thermocouple to maintain control of a silicone oil bath. The reactor was maintained under an inert nitrogen atmosphere using a double tube gas manifold connected in parallel to an airless oil sparger. Vacuum was applied using the same collector connected in parallel to a high vacuum Welch pump. The polyol was charged to the reactor and placed under a nitrogen atmosphere. Anhydrous 1,2-dichloroethane was introduced into the reactor to facilitate the separation of the water from the polyol and the temperature was raised to 120 ° C. When the water was of < 10 ppm Adipoyl chloride was added to the reactor from a clean, dry syringe. The reaction mixture begins to foam, indicating a rapid evolution of gaseous hydrogen chloride ("HCL"). After 5 minutes, a nitrogen spray tube was introduced into the reactor and the upper part of the reactor was opened to the atmosphere to facilitate the ventilation of the HCL gas. After an additional 5 minutes, solvent removal was initiated by continuous filling and draining of the Dean Stark trap distillate. The temperature of the oil bath was slowly raised to 200 ° C and maintained for 1 hour under vacuum of < 10 mm Hg. After 1 hour, the bath temperature was lowered to 160 ° C while maintaining the vacuum for 15 hours. The product was discharged and its melt flow was determined.

EXAMPLE 9 PREPARATION OF PQLIQL CAPROLAC-TQNA INITIATED CQN BEPD A procedure practically as described in Example 2 was followed to prepare a caprolactone polyol initiated with BEPD. A polyol with a hydroxyl number of 22 was obtained. The molecular weight of the polyol based on its hydroxyl number was 5100.

EXAMPLE 10 PREPARATION OF CAPROLACTONE POLYOL INITIATED WITH BEPD AND ADIPOILQ CHLORIDE A procedure practically similar to that described in Example 8 was followed to react the caprolactone polyol initiated with BEPD of Example 9 with adipoyl chloride. Upon completion the product was discharged and its fluidity in the molten state was determined EXAMPLE 11 PREPARATION OF COPOLYMER e-CAPROLAC ONA / t-BU ILCAPROLACTONE T-butylcaprolactone was obtained by performing the reaction Baeyer Villiger on 4-t-butylcyclohexanone, the details of which are known to those skilled in the art. A procedure substantially similar to that described in Example 2 was followed to prepare copolymers of e-caprolactone / t-butylcaprolactone. Typically, the reactor was charged with 95 mol% e-caprolactone and 5 mol% t-buticaprolactone. Upon completion the polymers were discharged and their melting index and molecular weight GPC were determined.

EXAMPLE 12 BIQDEGRADABILITY TEST The biodegradability of the caprolactone copolymer initiated with BEPD adipate from Example 2 was determined from the theoretical percent of C0 produced using the standard test method ASTM D-5338. A cellulose control was used and the samples were run in duplicate.

Net theoretical C02 days cellulose copolymer adipate BEPD i 1.46% 3.16% 3 25.37% 13.75% 5 50.03% 21.15% 10 70.04% 43.50% 15 77.15% 75.86% 20 84.00% 93.52% EXAMPLE 13 PREPARATION OF COMPOUNDS AND BLOWED FILM Composition The mixtures that were extruded in blown film were composed in a Brabender Prep. -Center® equipped with four heating zones; a double-screw extruder D6 / 2 of 42 mm having rotary counter propellers, constant take in a length / diameter ratio (L / D) of 7: 1; and a granulation nozzle. Upon exiting the extruder, the composite strands were passed through a water bath maintained at 10 ° C, dried by an air knife and granulated. The operating parameters were: Zone temperature: zones 1 to 4 150 ° to 180 ° C Nozzle temperature: 150 ° to 180 ° C Melt temperature: 160 ° to 190 ° C Propeller speed 75 rpm Blown film Composite polymers and pure polymers were converted into blown film using the Brabender Prep. -Center® or a line of Sterling film. The Brabender Prep. -Center® was equipped with a 0.75 inch ventilated single-screw extruder with a 25: 1 L / D and a compression ratio of 2: 1, fitted with a 2-inch blown film nozzle equipped with a 3S 2-inch Brabender single-lip air ring with cooled air. Cooperating parameters were: Zone temperature: zones ia R p • - i QM • Nozzle temperature: 150C-180 ° C Melt temperature: 130o-180 ° C Propeller speed 25 rpm Caliber: 1-1.5 mils The Sterling blown film line was equipped with a single-helix 1.5-inch linear density polyethylene helix having an L: D of 24: 1, adapted with a 3-inch nozzle, nozzle spaces of 40 mils and 80 mils and a 3-inch Sano, double-arm air ring with cooled air. The operating parameters were: Zone temperature: zones 1 to 4 85 ° -110 ° C Nozzle temperature: Q 0_1 in ° P Melt temperature: 95 ° -120 ° C Nozzle speed 1.40 Ib / hr-in Caliber: 1-1.5 mils EXAMPLE 14 RSI EVALUATION OF POLYMERS The BEPD adipate polymers prepared according to the procedure set forth in Example 2 were compressed into plates for evaluation. The polymers of the present invention have unique rheological properties that suggest a different molecular structure and impart better stiffness in manufactured blown films. These unique rheological properties also favor the relative ease of fabrication in finished products, especially in the extrusion of films. In particular, these polymers have melting indices (MI) and indices of the relaxation spectrum (RSI) such that, for a given polymer, they are approximately 4.0 < (RSI) (MI0") <approximately 15.0, or approximately 4.0 <RSI <30.Q, most preferably close _ 0 54 of 4.2 < (RSi) (MI ") <approximately 10.0 or approximately 4.2 <; RSI < 25.0. In the above formulas, the MI is the melt index of the polymer reported as grams per 10 minutes determined according to ASTM D-1238, condition B, at 125 ° C and 2.16 kg, and the RSI is in units without dimension, measured at 75 ° C. To compare similar polymers having different melting indices, the RSI is normalized according to the previous R.SI-MI ratio, where the 0.54 exponential was determined experimentally. The following examples demonstrate that the incorporation of short chain branches increases the RSI through the broadening of the molecular weight distribution. The addition of SCB and LCB also increases the P, SI. The TONE® Polymer P-787 is the control and designated as Example 14-a, this increase in the RSI is not only observed in the homopolymers shown in Examples 14b-g, but also in Example 14-h a composite polymer . Example 14-h is a composite mixture of TONE® Polymer P-300 (a linear polymer of Mn 10,000), a branched PCL copolymer which can not be converted into a film and the copolymer of Example 15-c.

EXAMPLE 14 EFFECTS OF THE BLOCK DIOL RAMIFICADO AMORFO ON THE PROPERTIES OF THE FILM The BEPD adipate copolymers prepared according to Example 2 were converted to film in the Brabender using the condit delineated in Example 13. The additof SCB in the adipate prepolymer backbone gives rise to a block of amorphous adipate that improves the stiffness properties of the film, such as the Elmendorf MD tear strength (MDET) and TD tensile shock resistance (TDTI). In addit a more balanced film is obtained when measured by the MD / TD tensile strength resistance ratio. The following table shows the improved stiffness properties as a result of the incorporatof SCB and LCB. Compared to Example 15-a, the control TONE® Polymer P-787, the Elmendorf MD tear strength improves and in many cases the TDET also improves. Once again it was observed that rigidity can be improved by mixing as shown in Example 15-1, which has the same compositas Example 14-h.

EXAMPLE 15 PROPERTIES OF THE STERLING FILM The BEPD adipate copolymers prepared in Example 2 were converted into a film in the Sterling line, according to the procedure mentd in Example 13. In comparison with the TONE P787 control, the Oracs were observed for TD tensile shock giving rise to a more balanced film as measured by the ratio of tensile shock and MD / TD tensile strength. The resistance to the fall of the dart and the perforatof the copolymer films were significantly improved, the resistance to tearing MD was improved and the stiffness of the film was reduced as observed by the lower secant modulus.

EXAMPLE 16 EFFECT OF THE AMORPHAL DIOL AND LCB BLOCK ON DENSITY The density of the polymers produced as described in Example 2 was determined. The additof a block of BEPD adipate alone or in combinatwith long chain branching, by the additof TMP, gave rise to copolymers with lower density. Of T f .'MERO DENSITY (g / cc) TONE P787 1.136 COPOLYMER OF ADIPATE BEPD 1.128 COPOLYMER OF ADIPATE BEPD / TMP J..x? EXAMPLE 17 PROPERTIES OF THE BRABENDER HDEMS FILM The HDEMS copolymers prepared in accordance with Example 4 were converted to film in the Brabender using the condit mentd in Example 13. Compared to TONE P787, films with significantly improved MD shock and puncture resistance were obtained.

COMPARATIVE EXAMPLE 18 COPIXÍMERQ FILM OF ADIPATQ BDQ SEMICRISTALINO, LINEAR By comparison with branched, amorphous BEPD adipate copolymers, a linear semicrystalline caprolactone copolymer was prepared as mentd in Example 6 and made into a film in the Brabender using the condit mentd in Example 13. the semicrystalline block produced by the butanediol adipate monomer gave rise to a polymer with lower tear resistance, tensile shock and puncture resistance compared to the polymers of Example 2.

EXAMPLE 19 INFLUENCE OF THE BLOCKS ON THE FUSPOINT AND CRYSTALLINITY OF THE COPOLYMER The palprolates of caprolactone are initiated with BDQ (Example 7) or BEPD (Example 9) and the chain was extended adipoyl chloride as described in Examples 8 and 10, respectively. The DSC shows that compared to the TONE P787 control, the melting point, the crystallizattemperature (Te), and the crystallinity are significantly reduced by the inclusof the amorphous BEPD block. The semicrystalline BDO block gave rise to an increase in Te. It was found that the semicrystalline BDPO block provides poor film properties.

EXAMPLE 20 BRANCHED CAPRQLACTQNA INFLUENCE ON THE POINT OF FUSAND CRYSTALLINATThe copolymer e-caprolactone / t-butylcaprolactone, prepared as described in Example 11 was compared to TONE P767 by DSC. The inclusof the branched caprolactone monomer gave rise to a reductin melting temperature, crystallinity and crystallizattemperature.

In addition to the specific aspects of the present invention described herein, those skilled in the art will recognize that other aspects will be within the scope of the invention.

Claims (20)

4R CLAIMS

1. A polymerized copolymer of: (a) a first monomer that is polymerized by condensation polymerization; and (b) a second monomer that is copolymerizable with the first monomer; characterized in that the second monomer is effective to eliminate the crystallinity of the copolymer.

2. The copolymer of claim 1, which is biodegradable.

3. The copolymer of claim 1 wherein the first monomer has a functional group selected from the group consisting of esters, ethers, carbonates, acetals, alcohols, acids, amines, amides, acid halides, isocyanates, and mixtures thereof.

4. The copolymer of claim 1, wherein the first cyclic monomer.

The copolymer of claim 1, wherein the first monomer is selected from the group consisting of lactones, lactides, lactams, polyols, urethanes, ureas, carbonates, acetals and mixtures thereof.

6. The copolymer of claim 1, wherein the first monomer is selected from the group consisting of caprolactone and derivatives thereof. 40

7. The copolymer of claim 1, wherein the second monomer is effective to initiate the polymerization of the first monomer.

The copolymer of claim 1, wherein the second monomer has a functional group selected from the group consisting of esters, ethers, carbonates, acetals, alcohols, acids, amines, amides, acid halides, isocyanates, and mixtures thereof.

9. The copolymer of claim 1, wherein the second monomer is selected from the group consisting of adipate and lactone esters.

10. The copolymer of claim 1, wherein the second monomer is effective to introduce amorphous regions in the copolymer.

11. The copolymer of claim 1, wherein the second monomer is effective to introduce branching into the copolymer.

The copolymer of claim 1, wherein the second monomer is a prepolymer having a molecular weight of from about 500 to 25,000 g / gmol.

The copolymer of claim 1, which is polymerized from about 99 to 80% by weight of the first monomer and from about 1 to 20% by weight of the second monomer.

14. The copolymer of claim 1, wherein the Kñ The copolymer has a depression of the crystallization temperature of at least about 2 ° C.

15. The copolymer of claim 1, which has a reduction in density of at least about 0.004 g / cc.

16. A film made from the copolymer of claim 1.

17. The film of claim 16 having a puncture resistance from about 3 to 50 in-Ibs / mil.

18. The film of claim 16 having a dart drop of at least 50 g / mil.

19. A method for improving the stiffness of a film, the method comprising the use of the polymer of claim 1 to manufacture the film.

20. A process for making a copolymer comprises polymerizing a first monomer which is polymerizable by condensation polymerization with a second monomer effective to eliminate the crystallinity of the copolymer. < ? t ': *' ít: * > $ SUMMARY OF THE INVENTION Condensation copolymers are described which are polymerized from a first monomer capable of polymerization by condensation polymerization, for example, polymerization of lactone with ring opening and a second monomer which is effective to eliminate crystallization of the copolymer. It is described that the removal of the crystallization can offer better properties 10 mechanics in the prepared films of the copolymers. As a result, the films prepared from the copolymers of the present invention may have properties that make them suitable for use as bags for garbage, h or n or raHahl or c:; a c: í p qn c