CA2068162C - Polymers of ethylenically unsaturated cyclic ortho esters - Google Patents

Abstract

Ethylenically unsaturated cyclic ortho esters are prepared by the reaction of a hydroxy-substituted cyclic ortho ester such as 4-hydroxymethyl-2-methoxy-2-methyl-1,3-dioxolane with acryloyl chloride, methacryolyl chloride, vinylbenzyl chloride or the like. They form polymers, especially random copolymers with styrene and EPDM graft copolymers; the latter are useful in the formation of copolymer-containing compositions with polyesters, polyamides and the like. The copolymer-containing compositions have excellent physical properties and may be employed to compatibilize blends of the same polymers.

Description

2~~~1~~

~Q!LYMERS OF ETHYLENICAL Y
N ATURATED CYCLIC ORTHO ESTERS
This invention relates to new polymers of ethylenically unsaturated monomers, and more particularly to polymers containing cyclic ortho ester functionality.
In recent years, there has been considerable interest in developing polymer compositions which include normally incom-patible polymers. Examples are compositions comprising linear polyesters such as p~oly(eth.ylene terephthalate) and poly(butylene terephthalate) in combinatian with olefin and olefin-diene polymers.
It might be expected that various properties of the linear polyesters, such as i;ensile strength, tensile elongation and impact 1 5 strength, would be improved by the addition of olefin or olefin-diene polymers. However, the resulting blends exhibit incompatibility as evidenced by gross phase separation and frequently degradation, rather than improvement, of physical properties.
One method of compatibilizing otherwise incompatible polymer blends is to incorporate therein a copolymer, typically a block copolymer, of irhe otherwise incompatible polymers.
Copolymers of this type can be formed by incorporating in one poly-mer structural units which are chemically reactive with the other polymer. Thus, for example, linear polyesters or polyamides having 2 5 terminal carboxylic acrid groups can undergo reaction with olefin or olefin-diene copolymers containing epoxy groups, either as sub-stituents on the polymer chain or as grafted units. Reference is made, for example, to U.S. Patent 4,965,111. Similarly, amine-ter-minated polyamides c:an undergo reaction with olefin or olefin-diene 3 0 polymers containing integral or grafted malefic anhydride moieties.
The resulting block copolymers do not exhibit the indicia of incom-patibility which are found in simple blends. Moreover, they are often useful as compatibili~:ers for blends of the otherwise incompatible forms of the two pol~rmers.
While polymers containing reactive substituents or grafted units such as epoxy and anhydride groups are known, many of them have not met with wide commercial acceptance. One possible reason is the relative chemical inactivity of such polymers, where-upon it is difficult to promote the copolymer-forming reaction to any substantial extent.
1 0 The present invention provides a wide variety of poly-mers, particularly copolymers, of ethylenically unsaturated monomers. These polymers contain highly reactive cyclic ortho es-ter groups as substituents. Said cyclic ortho ester groups can un-dergo reaction with numerous other polymers, forming copolymer-containing compositions with excellent properties.
Accordingly, the invention includes polymers comprising structural units of the formula ( CHZ ) ~-O
-CH-C-(I) .0R1 6 ~ 4 33 R X-O f R ~ C-R C
R
( CHy ) m-O
wherein:
R 1 is C~ _ 1 o primary or secondary alkyl or aralkyl or a C6-~ o aromatic radical, and R2 is C~ _~ p primary or secondary alkyl or aralkyl or a C6_~ o aromatic radical, or R~ and R2 together with 2 5 the atoms connecting them form a 5-, 6- or 7-membered ring;
R3 is hydrogen or C~ _4 primary or secondary alkyl;

R4 is an unsubstituted or substituted C1 _6 alkylene or C6_~o arylene radical;
RS is hydrogen or methyl;
R6 is hydrogen, C~_6 alkyl or a C6_io aromatic radical;
X is a substantially inert linking group;
m is 0 or 1;
n is from 1 to 2-m; and p is 0 or 1.
An essential feature of the polymers of this invention is the presence of cyclic; ortho ester moieties. The R~ value therein may be a C1 _4 primary or secondary alkyl radical such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or secondary butyl, or an aralkyl or aromatic radical as defined above. Any substituents should be non-reactive under the conditions of the invention; exam-pies are halo, vitro and alkoxy. Unsubstituted primary radicals and especially the methyl radical are generally preferred.
The R2 value may be a C~ _4 primary or secondary alkyl, aralkyl or aromatic radical as defined above for R~ . It is also pos-sible for R~ and R2 together to form a 5-, 6- or 7-membered ring with the atoms connecting them. Thus, the invention includes com positions prepared from certain spiro ortho ester compounds.
The R3 radical may be hydrogen or an alkyl radical simi-lar to R~ and R2. It is preferably hydrogen.
The R4 radical is an unsubstituted or substituted C~ _6 2 5 alkylene radical, any substituents being inert to ortho ester forma-tion and reaction with aryl chlorides; e.g., alkoxy. Preferably, R4 is methylene.
The Rs radical may be hydrogen, alkyl or aryl as previ-ously defined. It is preferably hydrogen.
3 0 The X value may be any linking group which is substan-tially inert under the conditions of formation and polymerization of the cyclic ortho ester, of the invention and copolymer formation from polymers thereof. Those skilled in the art will understand that a wide variety of groups fit this description, and the invention is not limited in that respect. Suitable X groups include unsubstituted and substituted divalent aliphatic, alicyclic and aromatic radicals and combinations thereof, any substituents being of the type previously described. Said radicals may be attached to other divalent radicals such as carbonyl, sulfone, carbamoyl, disubstituted silicon and alkyl- and arylphosphoryl. The preferred X groups have the formulas 1 0 ( I I ) -IC- and ( I I I ) ___,~~ .
1 5 The polymers of this invention include those of the type which may be preparE~d from acrylic and methacrylic acid esters, wherein X has formula II, as well as vinylbenzyl ethers, wherein X
has formula III. Both vinyl-derived (RS is hydrogen) and isopropenyl-derived (R5 is methyl) polymers are included; for example, polymers 20 of acrylic and methacrylic acid esters. For the most part, R5 is preferably hydrogen when X has formula III.
The values of m and n depend on whether the cyclic ortho ester moiety is a 5-membered or 6-membered ring. In general, 5-membered rings are preferred; that is, m is 0 and n is 1. However, 2 5 the invention also includes polymers in which a 6-membered ring is present, which requires either that m and n both be 1 or that m be 0 and n be 2.

Also included are polymers in which p is 0; that is, compounds not containing an R4 value. Most often, p will be 0 when the ortho ester ring is a 6-membered ring.
Many of i:he ethylenically unsaturated cyclic ortho esters s which may be converl:ed to the polymers of this invention are disclosed and claimed in commonly owned Canadian Patent application Serial No.
2,056,510 filed Novernber 11, 1991. Esters of this type may be prepared by the reaction of a h~ydroxy-substituted ortho ester of the formula ( CHI ) "-O OR1 (IV) EIO"'tR4~----C-R3 ' C
( CHZ ) m-O RZ
wherein R'-4, m, n and p are as previously defined, with a suitable reagent such as acryl~oyl chloride, methacryloyl chloride or a vinylbenzyl chloride. Said reaction takes place under conventional conditions. In the case of acryloyl chloride or methacryloyl chloride~it typically occurs in the presence of a tE~rtiary amine as acid acceptor and in solution in a relatively non-polar organic solvent. The hydroxy-substituted ortho ester and acryloyl or methy~~cryloyl chloride may be employed in approximately equimolar amounts, or the chloride may be employed in slight excess. The amine is generally present in excess, to ensure neutralization of all the acidic by-product formed.
zo Reaction between the hydroxy-substituted ortho ester and vinylbenzyl chloride is also conducted under conventional conditions, typically in the presence of an alkaline reagent such as sodium hydroxide. Again, the hydroxy-substituted ortho ester and vinylbenzyl chloride may be employed in roughly equimolar amounts, 25 Or, in this case, an e:KCess of the ortho ester may be employed. The molar proportion of base is generally about equal to that of ortho ester. No solvent is generally necessary, although one may be em-ployed if desired.
The preparation of ethylenically unsaturated cyclic ortho esters is illustrated by the following examples. Molecular struc-tures of all products in Examples 1-4 were confirmed by proton and carbon-13 nuclear magnetic resonance spectroscopy.
Exam lio a 1 A 5-liter 3-necked flask fitted with a mechanical stir-rer, pressure equalizing addition funnel and nitrogen inlet was charged with 301 grams (2.03 moles) of 4-hydroxymethyl-2-methoxy-2-methyl-1,3-dioxolane, 514 grams (5.08 moles) of tri-ethylamine and 2 liters of methylene chloride. The flask was im-1 5 mersed in an ice-water bath and 193.1 grams (2.13 moles) of acryloyl chloride was added over 50 minutes under nitrogen, with stirring. The mixture was stirred at room temperature overnight and the filtrate was washed twice with 2-liter portions of water, dried over magnesium sulfate, filtered and vacuum stripped. A free radical inhibitor, 3-t-butyl-4-hydroxy-5-methylphenyl sulfide, was added in the amount of 200 ppm. to the residue which was then dis-tilled under vacuum. The desired 4-acryloyloxymethyl-2-methoxy-2-methyl-1,3-dioxolane distilled at 80-85°C/0.5-1.0 torr.
2 5 Examl to a 2 The procedure of Example 1 was repeated, employing 281 grams (1.9 moles) of 4-hydroxymethyl-2-methoxy-2-methyl-1,3-dioxolane, 481 grams (4.76 moles) of triethylamine and 199 grams 3 0 (1.9 moles) of methacryloyl chloride. The product, 4-methacryloyl-oxymethyl-2-methoxy-2-methyl-1,3-dioxolane, was collected at 80°C/0.4 torr.

- ~ - 2~~~1~2 Example 3 .
The procedure of Example 1 was repeated, employing 21 grams (100 mmol.) of 4-hydroxymethyl-2-methoxy-2-phenyl-1,3-dioxolane, 25.3 gram.; (250 mmol.) of triethylamine, 9.5 grams (105 mmol.) of acryloyl chloride and 150 ml. of methylene chloride. The crude product was purified by column chromatography over basic alumina, using 15% (by volume) ethyl acetate in hexane as an eluant, 1 0 to yield the desired 4-acryloyloxymethyl-2-methoxy-2-phenyl-1,3-dioxolane.
Exam Ip a 4 A 4-neckE~d 250-ml. round-bottomed flask equipped with a mechanical stirrer, a pressure equalizing addition funnel, a con-denser and a thermonneter was charged with 51.9 grams (350 ml.) of 4-hydroxymethyl-2-m~~thoxy-2-methyl-1,3-dioxolane and 14.01 grams (350 mmol.) of powdered sodium hydroxide. The slurry was stirred for 15 minute:. under nitrogen, after which 41.1 grams (270 mmol.) of vinylbenzyl chloride (isomeric mixture) was added drop-wise over 10 minutes. The mixture was heated to 80°C, whereupon an exothermic reaction took place which caused the temperature to rise to 140°C. The rnixture was stirred overnight under nitrogen, diluted with 400 ml. of methylene chloride and 5 ml. of triethyl-amine and washed twice with 250 ml. of aqueous sodium chloride solution. The organic; layer was dried over magnesium sulfate, fil-tered and vacuum stripped, and the residue was purified by column chromatography over basic alumina using a 2:1 (by volume) mixture 3 0 of hexane and methylf~ne chloride as eluant. There was obtained the desired isomeric mixture of 4-(2-methoxy-2-methyl-1,3-dioxo-lanyl)methyl vinylbenzyl ethers.

~o~~~~
-$_ The polymers of this invention may be prepared by poly-merization of the ethylenically unsaturated cyclic ortho esters un-der free radical conditions, either alone or in the presence of other monomers. The term "polymer", as used herein, includes addition homopolymers and, especially, copolymers with one or more other monomers.
Polymerization by the free radical method may be ef-fected in bulk, solution, suspension or emulsion, by contacting the monomer or monomers with a polymerization initiator either in the 1 0 absence or presence of a diluent at a temperature of about 0°-200°C.
Suitable initiators include benzoyl peroxide, hydrogen peroxide, azobisisobutyronitrile, persulfate-bisulfite, persulfate-sodium formaldehyde sulfoxylate, chlorate-sulfite and the like.
Alternatively, polymerization may be effected by irradiation tech-piques, as by ultraviolet, electron beam or plasma irradiation.
A large variety of polymerizable compounds can be used to form copolymers of this invention. They include the following:
(1 ) Unsaturated alcohols and esters thereof: Allyl, methallyl, crotyl, 1-chloroallyl, 2-chloroallyl, cinnamyl, vinyl, 2 0 methylvinyl, 1-phenallyl and butenyl alcohols and esters of such al-cohols with saturated acids such as acetic, phenylacetic, propionic, butyric, valeric, caproiic and stearic; with unsaturated acids such as acrylic, a-substituted acrylic (including alkylacrylic, e.g., methacrylic, ethylacrylic, propylacrylic, etc. and arylacrylic such as phenylacrylic), crotonic, oleic, linolenic and linolenic; with polyba-sic acids such as oxalic, malonic, succinic, glutaric, adipic, pimelic, suberic, azelaic and :~ebacic; with unsaturated polybasic acids such as malefic, fumaric, citraconic, mesaconic, itaconic, methylene-malonic, acetylenedicarobxylic and aconitic; and with aromatic 3 0 acids, e.g., benzoic, phthalic, terephthalic and benzoylphthalic acids.
(2) Unsaturated acids (examples of which appear above) and esters thereof with lower saturated alcohols, such as methyl, 20~~1~~
_g_ ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, 2-ethylhexyl and cyclohexyl alcohols and with saturated lower poly-hydric alcohols such as ethylene glycol, propylene glycol, tetra-methylene glycol, neopentyl glycol and trimethylopropane.
(3) Unsaturated lower polyhydric aicohols, e.g., butene-diol, and esters therE~of with saturated and unsaturated aliphatic and aromatic, monobasic and polybasic acids, examples of which appear above.
(4) Esters of the above-described unsaturated acids, es-pecially acrylic and methacrylic acids, with higher molecular weight monohydroxy and polyhydroxy materials such as decyl alcohol, iso-decyl alochol, oleyl alcohol, stearyl alcohol, epoxy resins and polybutadiene-derived polyols.
(5) Vinyl ~~yclic compounds including styrene, o-, m-, p-chlorostyrenes, bromostyrenes, fluorostyrenes, methylstyrenes, ethylstyrenes. and cyanostyrenes; di-, tri- and tetrachlorostyrenes, bromostyrenes, fluorostyrenes, methylstyrenes, ethylstyrenes, cyanostyrenes; vinylnaphthalene, vinylcyclohexane, divinylbenzene, trivinylbenzene, allylbenzene and heterocycles such as vinylfuran, vinylpridine, vinylben;zofuran, N-vinyl carbazole, N-vinylpyrrolidone and N-vinyloxazolidone.
(6) Unsaturated ethers such as methyl vinyl ether, ethyl vinyl ether, cyclohexyl vinyl ether, octyl vinyl ether, diallyl ether, ethyl methallyl ether and allyl ethyl ether.

(7) Unsaturated ketones, e.g., methyl vinyl ketone and ethyl vinyl ketone.

(8) Unsaturated amides, such as acrylamide, meth-acrylamide, N-phenylacrylamide, N-allylacrylamide, N-methylol-acrylamide, N-allylcap~rolactam and diacetone acrylamide.
3 0 (g) Unsaturated aliphatic hydrocarbons, for instance, ethylene, propylene, butenes, butadiene, isoprene, 2-chlorobutadiene and a-olefins in general.

(10) Unsaturated alkyl halides, e.g., vinyl fluoride, vinyl chloride, vinyl bromicje, vinylidene chloride, vinylidene bromide, allyl chloride and allyl bromide.
(11 ) Unsaturated acid anhydrides, e.g., malefic, citraconic, itaconic, bis-4-cyclohexane-1,2-dicarboxylic and bicyclo(2.2.1.)-5-heptene-2,3-dicarboxylic anhydrides.
(12) Uns~~turated nitrites, e.g., acrylonitrile, meth-acrylonitrile and other substituted acrylonitriles.
Random addition polymers are within the scope of the in-vention, and copolymers with vinylaromatic compounds such as styrene are preferred. Also preferred are graft copolymers prepared by grafting the ethylenically unsaturated cyclic ortho esters on previously formed polymers. More preferably, said graft copolymers are copolymers comF~rising ethylene and propylene structural units;
and still more preferably, copolymers also comprising structural units derived from at least one non-conjugated diene, said copoly-mers frequently beincl identified hereinafter as "EPDM copolymers".
Such graft copolymer:; may be conveniently prepared by absorption of the ethylenically unsaturated ortho ester and a free radical polymerization cataly:;t on the EPDM copolymer followed by grafting, frequently effected by extrusion at a temperatures in the range of about 150-300°C.
The preparation of the copolymers of this invention is illustrated by the following examples. Molecular weights, when 2 5 given, are weight average and were determined by ge! permeation chromatography relative to polystyrene.
Examples 5-9 3 0 Mixtures of various ethylenically unsaturated ortho esters and 1 gram of 2,5-dimethyl-2,5-di(t-butylperoxy)hexane were premixed and combined with 1 kilogram of a commercially ~~~~16~

available EPDM copolymer containing about 83 mole percent ethylene and about 5.4 mole percent norbornene units. .The blends were stored for about 16 hours at 20°C to enable the ortho ester and polymer-ization initiator to be completely absorbed by the EPDM pellets, and were then extruded on a twin-screw extruder with zone set tem-peratures ranging frorn 120° to 205°C. The extrudates were cooled in a water bath, pelletized and dried in vacuum.
The proportion of the ethylenically unsaturated ortho ester grafted on the E:PDM copolymer was determined by dissolving a 1 0 sample of the graft copolymer in xylene at about 130°C, pouring the resulting solution inta~ acetone and filtering and drying the purified copolymer, which was then analyzed by Fourier transform infrared spectroscopy. Gel content was determined by continuous extraction with hot xylene for 4f3 hours followed by drying and weighing of the insoluble residue. The results are given in Table I, with all percent-ages being by weight.
2 0 Example Ortho ester:
Example 1 1 1 2 3 Percent based on EPDM copolymer 0.3 1.0 3.0 1.0 1.3 Amount grafted, % >90 >90 >90 50 - -Gel, % 0 4 0 4 0 0 - -A 5-liter 3-necked flask equipped with a reflux con-denser and nitrogen purge means, a mechanical stirrer and a ther-mometer was charged with 936 grams (9 moles) of styrene,. 960 ml.
of methyl ethyl ketone, 960 mg. of azobisisobutyronitrile and 31 grams (150 mmol.) of the product of Example 1. The solution was purged with nitrogen for 30 minutes, after which it was heated at 70°C under nitrogen for 15 hours. An additional 600 mt. of methyl ethyl ketone and 500 mg. of azobisisobutyronitrile were added and stirring and heating were continued at 70°C for 4 hours. The solu-tion was cooled to room temperature and poured into twice its vol-ume of methanol, with rapid stirring. The precipitated product was filtered, slurried several times in methanol and refiltered, and vacuum dried at 60°C for 48 hours. It was shown by nuclear mag-netic resonance and Fourier transform infrared spectroscopy to be 1 0 the desired copolymer of styrene and the ortho ester acrylate, con-taining 2.2 mole percent ortho ester groups. Its molecular weight was 102,000. .
Exam I~e 11 Following the procedure of Example 10, a polymer con-taining about 2.5 molE; percent ortho ester groups was prepared by the reaction of 498 grams (4.79 moles) of styrene with 21.8 grams (108 mmol.) of the product of Example 1 in 346 ml. of toluene, using 5.2 grams of azobisisobutyronitrile. The reaction mixture was di-luted with an additional 500 ml. of toluene prior to isolation of the product, which had a molecular weight of about 50,000.
Exam IR a 12 Following irhe procedure of Example 11, a product con-taining 1.6 mole percent ortho ester groups was prepared by the re-action of 359 grams (3.45 moles) of styrene, 20 grams (76 mmol.) of the product of Example 4, 252 ml. of toluene and 3.79 grams of azo-bisisobutyronitrile. It, molecular weight was 58,000.
Certain polymers of this invention react with other polymers containing reactive groups, particularly those capable of nucleophilic substitution such as amine, hydroxy, thio and carboxy groups and functional derivatives thereof, to form copolymer-containing compositions. Included are copolymer-containing compositions with polymers otherwise incompatible with EPDM copolymers, including s linear polyesters and polyamides. Such copolymer-containing compositions and the method for their preparation are disclosed and claimed in commonly owned U.S. Patent 5,132,361.
By reason of the presence of the copolymer, said compositions are compatible and may be molded into articles having to excellent physical properties. They are also useful for further compatibilizing blends of the two polymers to form molding compositions having similar excellent properties.
Polyesters suitable for preparing copolymer-containing compositions include those comprising structural units of the formula O O
II 1l 15 (v) -O-R6-O-C-A1-C-wherein each R6 is independently a divalent aliphatic, alicyclic or aromatic hydrocarbon or polyoxyalkylene radical and A' is a divalent aromatic radical. Such polyesters include thermoplastic polyesters illustrated by poly(alkylene dicarboxylates), elastomeric polyesters, ao polyarylates, and polyester copolymers such as copolyestercarbonates.
Because the principal reaction which occurs with the ortho ester groups involves a carboxylic acid group of the polyester, it is highly preferred that said polyester have a relatively high carboxylic end group concentration. Concentrations in the range of about 5-250 is microequivalents per gram are generally suitable, with 20-150 microequivalents per gram being preferable and 20-80 being particularly desirable.

20~~~.~~

The polyester may include structural units of the for-mula \ ~ /~\ z II
(VI) -O-R6-O-C-AZ N-R -N A -C-~C~ \C~

wherein R6 is as previously defined, R~ is a polyoxyalkylene radical and A2 is a trivalent aromatic radical. The A~ radical in formula V
is most often p- or m-phenylene or a mixture thereof, and A2 in for-mula VI is usually derived from trimellitic acid and has the struc-10 ture The R6 radical may be, for example, a C2-~ p alkylene 1 5 radical, a C6_~ o alicyc:lic radical, a C6_2o aromatic radical or a polyoxyalkylene radical in which the alkylene groups contain about 2-6 and most often 4 carbon atoms. As previously noted, this class of polyesters includes the poly(alkylene terephthalates) and the polyarylates. Poly(alkylene terephthalates) are frequently pre-ferred, with polyethylene terephthalate) and poly(butylene tere-phthalate) being most preferred.
The preferred polyesters are polyethylene terephtha-late) and poly(butylenis terephthalate), generally having a number average molecular weight in the range of about 20,000-70,000, as ~0~~1~~

determined by intrinsic viscosity (IV) at 30°C in a mixture of 60%
(by weight) phenol and 40% 1,1,2,2-tetrachloroethane.
Polyamide~s may also be employed for the formation of copolymer-containing compositions. Included are those prepared by the polymerization of a monoamino-monocarboxylic acid or a lactam thereof having at least 2 carbon atoms between the amino and car-boxylic acid group, of substantially equimolar proportions of a di-amine which contains at least 2 carbon atoms between the amino groups and a dicarbo.xylic acid, or of a monoaminocarboxylic acid or a lactam thereof as defined above together with substantially equimolar proportions of a diamine and a dicarboxylie acid. (The term "substantially equimolar"- proportions includes both strictly equimolar proportions and slight departures therefrom which are in-volved in conventional techniques for stabilizing the viscosity of the 1 5 resultant polyamides.) The dicarboxylic acid may be used in the form of a functional cjerivative thereof, for example, an ester or acid chloride.
Examples of the aforementioned monoamino-mono-carboxylic acids or lactams thereof which are useful in preparing the polyamides include those compounds containing from 2 to 16 car-bon atoms between the amino and carboxylic acid groups, said carbon atoms forming a ring .containing the -CO-NH- group in the case of a lactam. As particular examples of aminocarboxylic acids and lac-tams there may be mentioned e-aminocaproic acid, butyrolactam, pivalolactam, e-caprolactam, capryllactam, enantholactam, un-decanolactam, dodecanolactam and 3- and 4-aminobenzoic acids.
Diamines suitable for use in the preparation of the polyamides include the straight chain and branched chain alkyl, aryl and alkaryl diamines. Illustrative diamines are trimethylene-diamine, tetramethyle~nediamine, pentamethylenediamine, octa-methylenediamine, hexamethylenediamine (which is often pre-~~6~~~~

ferred), trimethylhexamethylenediamine, m-phenylenediamine and m-xylylenediamine. .
The dicarboxylic acids may be represented by the formula HOOC-Y-COOH
wherein Y is a divalent aliphatic or aromatic group containing at least 2 carbon atoms. Examples of aliphatic acids are sebacic acid, octadecanedioic acid, suberic acid, glutaric acid, pimelic acid and adipic acid.
Both crystalline and amorphous polyamides may be em-ployed, with the crysl:alline species often being preferred by reason of their solvent resistance. Typical examples of the polyamides or nylons, as these are often called, include, for example, polyamide-6 (polycaprolactam), 66 (polyhexamethylene adipamide), II, 12, 63, 64, 6/10 and 6/12 as well as polyamides from terephthalic acid and/or isophthalic acid and trimethylhexamethylenediamine; from adipic acid and m-xylylenediamines; from adipic acid, azelaic acid and 2,2-bis(p-aminophenyl)propane or 2,2-bis-(p-aminocyclohexyl)propane and from terephthalic acid and 4,4'-diaminodicyclohexylmethane.
Mixtures and/or copolymers of two or more of the foregoing polyamides or prepolymers thereof, respectively, are also within the scope of the present invention. Preferred polyamides are polyamide-6, 46, 66, II and 12, most preferably polyamide-66.
For the preparation of copolymer-containing composi-tions, a blending method which results in the formation of an inti-mate blend is preferred. Suitable procedures include solution blending, although such procedures are of limited applicability to many polyesters and polyamides by reason of their insolubility in 3 0 most common solvent;. For this reason and because of the availa-bility of melt blending equipment in commercial polymer processing facilities, melt reaction procedures are generally preferred.
Conventional melt blending procedures and equipment may be em-206~.~.6~

ployed, with extrusion often preferred because of its relative con-venience and particular suitability. Typical reaction temperatures are in the range of about 175-350°C.
Those skilled in the art will be familiar with blending methods and apparatus capable of intimately blending resinous constituents, especially by kneading. They are exemplified by disc-pack processors and various types of extrusion equipment.
Illustrations of the I<~tter are continuous mixers; single screw kneading extruders; counterrotating, non-intermeshing twin screw extruders having screws which include forward-flighted com-pounders, cylindrical bushings and/or left-handed screw elements;
corotating, intermeshing twin screw extruders; and extruders having screws which include at least one and preferably at least two sec-tions of kneading block elements.
In addition to copolymer, the copolymer-containing com-positions may also c~~ntain unreacted polyester, polyamide or the like. In any event, molded parts produced from said compositions are generally ductile and have higher impact strengths, tensile strengths and/or tensile elongations than those produced from sim-ple blends, which are incompatible and often exhibit brittleness or delamination.
There may also be present in the copolymer-containing compositions conveni:ional ingredients such as fillers, flame retar-dants, pigments, dyes, stabilizers, anti-static agents, crystalliza-2 5 tion aids, mold release agents and the like, as well as resinous com-ponents not previously discussed including auxiliary impact modify-ing polymers.
The proportions of ortho ester polymer, other polymer and other resinous materials are not critical; they may be widely 3 0 varied to provide compositions having the desired properties. Most often, the ortho ester polymer is employed in an amount in the range I ~I

_18_ of about 5-95%, preferably about 5-65%, of the composition by weight.
In addition to forming copolymer-containing compositions that act as compatibilizers in the manner described hereinabove, various copolymers of this invention and especially random copolymers with s styrene can compatibilize blends of other, largely dissimilar polymers in which they are incorporated, as disclosed and claimed in, commonly owned U.S. Patent 5,231,132.
The preparation of copolymer-containing compositions from the polymers of this invention is illustrated by the following examples.
~o All percentages are by weight.
Dry blends comprising ortho ester-grafted EPDM
copolymers and poly(butylene terephthalate) were prepared and extruded at temperatures in the range of 250°C. The extrudates were desired copolymer-containing compositions; they were pelletized, dried and molded into test specimens which were tested for tensile strength and elongation (ASTM procedure D638) and notched Izod impact strength (ASTM procedure D256).
The results are given in Tables II and III, in comparison with ao five controls employing (A-D) a blend prepared from unfunctionalized EPDM copolymer, and (E) a blend prepared from EPDM copolymer similarly grafted with 3% glycidyl methacrylate.
Example Control Control Polyester, parts 50 50 50 50 50 Ortho ester- grafted EPDM:

Example 5 6 8 - - - -Parts 50 50 50 50 50 Tensile strength, MPa. 16.9 24.2 17.3 13.9 18.5 Tensile elongation, %~ 240 370 290 65 230 TABLE III
Example Control ~s ~7 ~8 ~9 2o a C o Polyester, parts 9 5 9 0 80 9 5 9 0 9 5 9 0 8 0 Ortho ester-grafted EPDM:

Example 6 6 6 9 9 - - - - - -Parts 5 1 0 20 5 1 0 5 1 0 2 0 Impact strength, joules/m. 64 641 849 264 844 27 32 53 From Table II, it is apparent that copolymer-containing compositions prepared from the EPDM copolymers of this invention have substantially higher tensile strengths and tensile elongations than the control empl~~ying an unfunctionalized EPDM copolymer.
They also have tensile strengths and elongations which are compa-rable to or greater than those of the control employing an EPDM
copolymer grafted with a substantially higher proportion of glycidyl 1 5 methacrylate. From fable III, it is apparent that each of the com-positions prepared from the polymers of this invention has a higher impact strength, and the products of Examples 17-20 a substantially higher impact strength, than those of the controls.
2 0 Exam to a 21 Following the procedure of Example 14, a similar blend was prepared in which the poly(butylene terephthalate) was replaced by a copolyester prepared from 1,4-butanediol and a 0.91:1 (by 25 weight) mixture of dimethyl terephthalate and a dimide-diacid re-action product of trimellitic acid and a polyoxypropylenediamine 20~~I ~

having an average molecular weight of about 200. Said blend had a tensile strength of 10.5 MPa. and a tensile elongation of 435%. A
control in which the ortho ester-grafted EPDM copolymer was re-placed by an EPDM copolymer grafted with 3% glycidyl methacrylate had a tensile strength of 7.7 MPa. and a tensile elongation of 505%.
Again, it is apparent that the graft copolymers of this invention may be employed at substantially lower levels of functionalization than corresponding glycidyl methacrylate graft copolymers, to obtain properties of the same order of magnitude.

Claims (21)

1. A polymer comprising structural units of the formula wherein:
R1 is C1-10 primary or secondary alkyl or aralkyl or a C6-10 aromatic radical, and R2 is C1-10 primary or secondary alkyl or aralkyl or a C6-10 aromatic radical, or R1 and R2 together with the atoms connecting them form a 5-, 6- or 7-membered ring;
R3 is hydrogen or C1-4 primary or secondary alkyl;
R4 is an unsubstituted or substituted C1-6 alkylene or C6-10 arylene radical;
R5 is hydrogen or methyl;
R6 is hydrogen, C1-6 alkyl or a C6-10 aromatic radical;
X is a substantially inert linking group;
m is 0 or 1;
n is from 1 to 2-m; and p is 0 or 1.

2. A polymer according to claim 1 wherein each of R1 and R2 is alkyl.

3. A polymer according to claim 2 wherein m is 0 and n is 1.

4. A polymer according to claim 3 wherein R3 and R6 are each hydrogen.

5. A polymer according to claim 4 wherein p is 1.

6. A polymer according to claim 5 which is a random addition polymer.

7. A polymer according to claim 6 which is a copolymer with styrene.

8. A polymer according to claim 5 which is a graft copolymer.

9. A polymer according to claim 8 which is a graft copolymer on a previously formed copolymer of ethylene and propy-lene.

10. A polymer according to claim 9 wherein R2 is methyl or phenyl.

11. A polymer according to claim 10 wherein R4 is methylene.

12. A polymer according to claim 11 which is a graft copolymer on a copolymer comprising structural units derived from ethylene, propylene and at least one non-conjugated diene.

13. A polymer according to claim 12 wherein X is

14. A polymer according to claim 13 wherein R2 is methyl.

15. A polymer according to claim 13 wherein R2 is phenyl.

16. A polymer according to claim 13 wherein R5 is hy-drogen.

17. A polymer according to claim 13 wherein R5 is methyl.

18. A polymer according to claim 12 wherein X is

19. A polymer according to claim 18 wherein R2 is methyl.

20. A polymer according to claim 18 wherein R2 is phenyl.

21. A polymer according to claim 18 wherein R5 is hydrogen.