3,021,316 United States Patent Office Patented Feb. 13, 1962 1 2 the cosmetic, wax, polish, molding, coating, etc., fields. 3,02,316 Other objects will become apparent to those skilled in PoLYMERIZATióNöFCYCLICESTERS the art in the light of the instant specification. Eugene F. Cox and Fritz Hostettler, Charleston, W. Va., In one embodiment the monomeric cyclic esters en assigners to Union Carbide Corporation, a corpora 5 ployed in the polymerization process of this invention tion of New York No Drawing. Filed Dec. 3, 1959, Ser. No. 856,911 can be characterized by the following formula: 30 Claims. (C. 260-78.3) I This invention relates to a process for polymerizing -O cyclic esters and to the products resulting therefrom. O (R-C-R). (R-C-R) o The most generally familiar works on the polymer (A) ization of actones are the now classical investigations wherein each R, individually, can be , alkyl, of W. H. Carothers. For instance, Carothers was able aryl, alkaryl, aralkyl, cycloalkyl, halo, haloalkyl, alk to polymerize delta-valerolactone to poly-delta-valerolac oxyalkyl, alkoxy, aryloxy, and the like; wherein A can tone by heating at 80-85 C. for a period of about 13 5 be an oxy (-O-) group, a thio (-S-) group, a di days, or by contacting delta-valerolactone with potas valent saturated aliphatic group, and the sium carbonate catalyst at a temperature of 80-85 like; wherein x is an integer from 1 to 15 inclusive; C. for a period of about 5 days. The resulting poly wherein y is an integer from 1 to 15 inclusive; wherein mers were soft waxes possessing average molecular z is an integer having a value of Zero or one; with the weights of approximately 2000 which had relatively low 20 provisos that (a) the sum of x-y--z cannot equal 3, thermal stabilities. The literature reports that attempts (b) the total number of atoms forming the cyclic ester to polymerize gamma-butyrolactone have been unsuc ring does not exceed 18, preferably does not exceed 9, cessful, and the corresponding polyester is not known. (c) the total number of organic substituents (such as In 1934, there was reported the preparation of poly those described for the R variables) attached to the epsilon-caprolactone by heating epsilon-caprolactone at 25 carbon atoms contained in the cyclic ester ring does not about 150 C. for a period of 12 hours, or by contacting exceed 4, preferably does not exceed 3, (d) from 2 to epsilon-caprolactone with potassium carbonate at about 4 continuously linked carbon atoms contained in the 150 C. for a period of 5 hours. The resulting epsilon cyclic ester ring can represent a portion of a saturated caprolactone polymers had melting points of about 53 cycloaliphatic hydrocarbon nucleus which contains from 55 C. and average molecular weights of about 4000. 30 4 to 10 ring carbon atoms, and (e) the four R variables The polymers were hard, brittle waxes which could not attached to any two adjacent carbon atoms contained be cold-drawn into fibers. Bischoff and Waldon 3 de in the cyclic ester ring can represent a portion of a fused scribe the transformation of glycolide under the influ aromatic hydrocarbon nucleus. ence of heat or a trace of zinc chloride into a polymeric With reference to Formula I supra, illustrative R rad Solid melting at 220 C. On being distilled in a vacuum 35 icals include, among others, methyl, ethyl, n-propyl, iso it was reconverted to the monomer melting at 86-87 propyl, n-butyl, sec-butyl, t-butyl, amyl, the hexyls, the C. The literature also reports the polymerization of heptyis, the octyls, dodecyl, octadecyl, phenyl, benzyl, lactide at elevated temperatures to a resinous mass. A tolyl, xylyl, ethylphenyl, butylphenyl, phenethyl, phenyl similar effect is also obtained at relatively lower tem propyl, phenylbutyl, cyclopentyl, 2-propylcyclohexyl, tures by employing potassium carbonate as the cata 40 cyclohexyl, 2-methylcyclohexyl, cyclohepty, chlorometh ySt. yl, chloroethyl, bromopropyl, bromobutyl, chloro, flu In a broad aspect the present invention is directed to oro, bromo, iodo, methoxymethyl, ethoxyethyl, propoxy the process for polymerizing monomeric cyclic esters in methyl, butoxypropyl, methoxy, ethoxy, n-propoxy, in contact with certain metal catalysts to produce butoxy, isopentoxy, n-hexoxy, 2-ethylhexoxy, 3-methyl useful polyester products, both the cyclic ester reagents 45 octoxy, decoxy, dodecoxy, octadecoxy, phenoxy, ethyl and the metal hydride catalysts being described herein phenoxy, propylphenoxy, dimethylphenoxy, phenylpro after in a more appropriate section. The average mo poxy, and the like. It is preferred that each R, individ lecular weights of the resulting polymers can range from ually, be hydrogen, alkyl, and/or alkoxy, and preferably about several hundred to about several thousand. The still, that each R, individually, be hydrogen, lower alkyl, homopolymers, copolymers, and terpolymers prepared 50 e.g., methyl, ethyl, n-propyl, isobutyl, and/or lower al by the practice of the instant invention are highly useful koxy, e.g., methoxy, ethoxy, propoxy, n-butoxy, and products as will become apparent at a later section here the like. It is further preferred that the total number in. In addition, the polymerization reaction can be con of carbon atoms in the substituents attached to the cyclic ducted at lower temperatures and at faster polymer ester ring does not exceed twelve. Cycloalkyl and lower ization rates heretofore unattainable in lactone polymer 55 alkyl-substituted cycloalkyl radicals which have from 5 ization art. to 7 carbon atoms in the cycloaliphatic nucleus also are Accordingly, one or more of the following objects will preferred. be achieved by the practice of this invention. In the discussion of the generic class of monomeric It is an object of this invention to provide a novel cyclic esters (Formula I) contemplated in the process process for homopolymerizing monomeric cyclic esters 60 of the invention, five provisos enumerated from (a) to produce useful homopolymers. It is another object through (e) have been set forth. Proviso (a) states of this invention to provide a novel process for poly that the sum x+y+z cannot be a number equal to three merizing an admixture containing at least two different This proviso excludes cyclic ester compounds, which monomeric cyclic esters to produce useful polymers. A 65 contain five atoms in the ring such as, for example, further object of the invention is to prepare lactone poly O. mers having a high degree of utility and application in C N 1. N O 1. Collected Papers of Wallace H. Carothers, edited by C I. MyCollec ag: S. SoYitby,p volume I, Interscience Publishers, / N Z Inc..Sir NSESSEE - if. W. Hill, and W. H. Carothers, Jour. 70 " Amer. Chem.Soc., 56.455 (1934). A gamma-butyrolactone , Ber. 36, 1200 (1903). 8,021,316 3 4 Prior art attempts to polymerize gamma-butyrolactone and the substituted gamma-butyrolactones have been un atoms designated by the numerals 7, 8, 9 and 10. The successful. Attempts to polymerize the cyclic esters, e.g., following compound further illustrates proviso (e). gamma - butyrolactones, beta-oxa-gamma-butyrolactones, O and the like, in the process of this invention likewise have 4o failed. One would postulate that the thermodynamic stability of these monomeric cyclic esters which contain five atoms in the lactone ring is much greater than the corresponding polymers, and that the free energy of in terconversion is exceedingly low. Proviso (c) states that O the total number of organic substituents attached to the carbon atoms contained in the cyclic ester ring should not 2-(2'-hydroxymethylphenyl)benzene carboxylic acid lactone exceed four, and preferably should not exceed three. It Representative monomeric cyclic esters which can be has been observed that when the total number of organic employed as starting materials in the method of the inven Substituents on the cyclic ester ring approached four or tion include, for example, beta-propiolactone, delta-valero more, then the polymerizability of the cyclic ester mon lactone, epsilon-caprolactone, 7-hydroxyheptanoic acid omer in the process of the invention diminished drasti lactone, 8-hydroxyoctanoic acid lactone, 12-hydroxydo cally. Proviso (d) states that from 2 to 4 continuously decanoic acid lactone, 13-hydroxytridecanoic acid lactone, linked carbon atoms contained in the cyclic ester ring 14-hydroxytetradecanoic acid lactone, 15-hydroxypenta can represent a portion of a saturated cycloaliphatic hy 20 decanoic acid lactone, 16-hydroxyhexadecanoic acid lac drocarbon nucleus which contains from 4 to 10 ring car tone, 17-hydroxyheptadecanoic acid lactone; the alpha, bon atoms such as, for example, a saturated cycloaliphatic alpha-dialkyl-beta-propiolactones, e.g., alpha, alpha-di hydrocarbon nucleus derived from , alkyl-sub methyl-beta-propiolactone, alpha, alpha-diethyl-beta-pro stituted cycloalkane, cyclobutane, cyclopentane, cyclohex piolactone, alpha, alpha-dipropyl-beta-propiolactone, and ane, cycloheptane, cyclooctane, methylcyclopentane, meth 25 the like; the monoalkyl-delta-valerolactones, e.g., the ylcyclohexane, and the like. Thus, for example, the foll monomethyl-, monoethyl-, monoisopropyl-, monobutyl-, lowing illustrative cyclic esters would be included in this monohexyl-, monodecyl-, and monododecyl-delta-valero proviso: lactones, and the like; the dialkyl-delta-valerolactones in which the two alkyl groups are substituted on the same 30 or different carbon atoms in the cyclic ester ring, e.g., the dimethyl-, diethyl-, diisopropyl-, dipentyl-, and di-n-octyl delta-valerolactones, and the like; the monoalkyl-, dialkyl-, or trialkyl-epsilon-caprolactones, e.g., the monomethyl-, monoethyl-, monoisopropyl-, monohexyl-, mono-n-octyl-, dimethyl-, diethyl-, di-n-propyl-, diisobutyl-, di-n-hexyl-, trimethyl-, triethyl-, and tri-n-propyl-epsilon-caprolac tones, and the like; the monoalkoxy- and dialkoxy-delta valerolactones and epsilon-caprolactones, e.g., monometh oxy-, monoethoxy-, monoisopropoxy-, -dimethoxy-, dieth 40 oxy-, and dibutoxy-delta-valerolactones and epsilon-capro lactones, and the like. Further illustrative cyclic esters include 3-ethyl-2-keto-1,4-dioxane, gamma(1-isopropyl-4- methylcyclohexyl)-epsilon-caprolactone, 3-bromo-2,3,4,5- tetrahydrobenzoxepin-2-one, 2-(2-hydroxyphenyl)ben 45 Zene carboxylic acid lactone, 10-hydroxyundecanoic acid lactone, 2,5,6,7,-tetrahydrobenzoxepin-2-one, 9-oxabicy clo[5.2.2] undecan-8-one, 4-oxa-14-hydroxytetradecanoic acid lactone, alpha, alpha-bis(chloromethyl)-propiolac tone, 1,4-dioxane-2-one, 3-n-propyl-2-keto-1,4-dioxane, 3 50 (2-ethylhexyl)-2-keto-1,4-dioxane, and the like. Illustra tive subclasses of cyclic esters which are eminently suitable in the process of the instant invention include the unsub 2-oxa bicyclo [3.2.2]nonan-3-one stituted lactones and the oxalactones which contain from Proviso (e) states that the four R variables attached to 6 to 8 atoms in the lactone ring, preferably delta-valero any two adjacent carbon atoms contained in the cyclic 55 lactone, epsilon-caprolactone, the keto-dioxanes, and the ester ring can represent a portion of a fused aromatic hy like; the mono- and polyalkyl-substituted lactones and drocarbon nucleus, that is, an aromatic nucleus derived oxalactones which contain from 6 to 8 atoms in the Iac from benzene, alkylbenzene, methylbenzene, propylben tone ring, preferably the mono- and poly-lower alkyl Zene, naphthalene and the like. To illustrate this proviso, delta-valerolactones, epsilon-caprolactones, and their cor the following compound is depicted structurally. 60 responding oxalactones wherein the alkyl substituent(s) contains from 1 to 4 carbon atoms, and the like; and the

mono- and polyalkoxy-substituted lactones and oxalac tones which contain from 6 to 8 atoms in the lactone ring, preferably the mono- and poly-lower alkoxy-delta-valero r 65 lactones, epsilon-caprolactones, and their corresponding S4 oxalactones wherein the alkoxy substituent(s) contains 2,3,4,5-tetrahydro-2-keto-benzoxepin from 1 to 4 carbon atoms. The unsubstituted and substituted delta-valerolactones, In the structurally depicted compound immediately above, epsilon-caprolactones, zeta-enantholactones, and higher the four R variables which were attached to the carbon 70 membered lactones, e.g., mono- and polyalkyl-substituted atoms designated by numerals 6 and 11 now represent a delta-valerolactones, mono- and polyalkoxy-substituted portion of the fused benzene ring, namely the carbon delta-valerolactones, mono- and polycycloalkyl-substitut ed delta-valerolactones, aryl-substituted delta-valerolac * W. H. Carothers, G.E. Corough, and F. J. van Natta, tones, mono- and polyhaloalkyl-substituted delta-valero Jour. Amer, Chem. Soc., 54,761 (1932). 75 lactones, mono- and polyalkyl-substituted 'epsilon-capro 8,021,816 5 6 lactones, mono- and polyalkoxy-epsilon-caprolactones, ployed, the particular catalyst employed, the concentra aryl-substituted epsilon-caprolactones, mono- and poly tion of the catalyst, and the like, the reaction temperature haloalkyl-substituted epsilon-caprolactones, mono- and can be as low as -40 C., and lower, and as high as polyalkyl-substituted zeta-enantholactones, and various 250° C., and higher. A suitable temperature range is other lactones described previously can be prepared by 5 from about -20° to about 225 C. A reaction tempera reacting the corresponding cyclic ketone with an an ture in the range of from about 0 to about 200° C. hydrous solution comprising peracetic acid and acetone. is preferred. It is desirable to add the peracetic acid solution to an The polymerization reaction preferably occurs in the excess of ketone, e.g., 5 to 1 molar ratio of ketone to liquid phase, and to this extent sufficient pressure is em peracetic acid, in a still kettle maintained under reflux. 0. ployed to maintain an essentially liquid reaction mixture The pressure can be adjusted so as to provide a kettle regardless whether or not an inert normally-liquid organic temperature of, for example, about 70° C. Acetone, vehicle is employed. Preferably, the polymerization re acetic acid by-product, and minor amounts of ketone action is conducted under an inert atmosphere, e.g., can be continuously removed throughout the addition nitrogen, , helium, etc. The ultimate molecular period. Subsequently, the lactone product can be re 5 weight of the resulting polymer will depend, to an extent, covered from the still kettle by conventional techniques upon various factors such as the temperature, the choice such as by distillation. and concentration of the catalyst, the use and amount Stoll and Rouvé5 report the preparation of lactones of an inert normally-liquid organic vehicle(s), and the which contain up to 22 carbon atoms in the lactone like. nucleus by a process which comprises contacting the 20 In general, the reaction time will vary depending on corresponding terminal hydroxy saturated aliphatic mono the operative temperature, the nature of the monomeric carboxylic acid with benzene-sulfonic acid catalyst in cyclic esters employed, the particular catalyst and the boiling benzene. These authors also report the prepara concentration employed, the use of an inert normally tion of other lactones such as 14-alkyl-14-hydroxytetra liquid organic vehicle, and other factors. The reaction decanoic acid lactone, e.g., 14-hydroxypentadecanoic 25 time can vary from several seconds to several hours, acid lactone, and oxa-15-hydroxypentadecanoic acid lac or more, depending on the variables illustrated above. tone, e.g., 12-Oxa-15-hydroxypentadecanoic acid lactone. It is preferred to conduct the polymerization reaction Palomaa and Tonkola teach the preparation of 3-oxa-6- in the essential absence of impurities which contain active hydroxyhexanoic acid lactone by heating the correspond hydrogen since the presence of such impurities tends to ing terminal hydroxy saturated aliphatic monocarboxylic 30 deactivate the catalyst and/or increase the induction acid. The preparation of 2-keto-1,4-dioxane, 3-alkyl-2- period. The minimization or essential avoidance of im keto-1,4-dioxane, polyalkoxy-substituted delta-valerolac purities such as water, carbon dioxide, aldehydes, ketones, tone, alkoxyalkyl-substituted delta-valerolactone, etc., is etc., is highly desirable. It is also preferred that the recorded by Carothers et al.". The preparation of di polymerization reaction be conducted under substantially aikyl-substituted, dihalo-substituted lactone, e.g., gamma, 35 anhydrous conditions. delta-dibromo-gamma, delta-dimethyl-delta-valerolactone When polymerizing an admixture containing at least is reported in the literature by Levina et al.8. German two different cyclic esters, the proportions of said cyclic Pat. No. 562,827 discloses the preparation of 2,3,4,5- esters can vary over the entire range. Broadly the con tetrahydrobenzoxepin-2-one whereas the literature9 re centration of each monomeric cyclic ester is in the range ports the position isomer, namely 2,5,6,7-tetrahydrobenz 40 of from about 3 to about 97 weight percent, based on the oxepin-2-one. Cycloalkyl-substituted epsilon-caprolac total weight of said cyclic esters. The preferred range tone, e.g., gamma(1-isopropyl-4-methylcyclohexyl)-epsi is from about 15 to about 85 weight percent. Admixtures lon-caprolactone is disclosed by Belov and Kheifits 0. containing epsilon-caprolactone and mono- and/or poly McKay et al. have recorded the preparation of halo alkyl-substituted epsilon-caprolactone (including isomeric Substituted, haloalkyl-substituted delta-valerolactone. The 45 mixtures thereof) are highly preferred as starting mate literature also reports the preparation of various other rials in the process of the invention. Admixtures contain cyclic esters. ing different mono- and/or polyalkyl-substituted epsilon The metal contemplated as catalysts in the caprolactones (including isomeric mixtures of the same process of the invention include the hydrides of Group and/or different mono- and/or polyalkyl-substituted ep A metals of the periodic table, i.e., , po 50 silon-caprolactones) also are highly preferred. tassium hydride, , hydride, and The polymers of this invention can be prepared via the cesium hydride; and the alkaline earth metal hydrides, i.e., bulk polymerization, Suspension polymerization, or the , strontium hydride, and barium hydride. solution polymerization routes. The polymerization re The catalysts are employed in catalytically significant action can be carried out in the presence of an inert nor quantities. In general, a catalyst concentration in the 55 maily-liquid organic vehicle such as, for example, aro range of from about 0.001, and lower, to about 10, and matic , e.g., benzene, toluene, xylene, ethyl higher, weight percent, based on the weight of total mono benzene, and the like; various oxygenated organic com meric feed, is suitable. A catalyst concentration in the pounds such as anisole, the dimethyl and diethyl ethers of range of from about 0.01 to about 3.0 weight percent is glycol, of propylene glycol, of diethylene glycol preferred. A catalyst concentration in the range of from 60 and the like; normally-liquid saturated hydrocarbons in about 0.05 to about 1.0 weight percent is highly preferred. cluding the open chain, cyclic, and alkyl-substituted cyclic For optimum results, the particular catalyst employed, the Saturated hydrocarbons such as , , various nature of the monomeric reagent(s), the operative condi normally-liquid petroleum hydrocarbon fractions, cyclo tions under which the polymerization reaction is conduct hexane, the alkylcyclohexanes, decahydronaphthalene, and ed, and other factors will largely determine the desired 65 the like. If desired, a mixture of mutually miscible inert catalyst concentration. normally-liquid organic vehicles can be employed. The polymerization reaction can be conducted over a The process of the invention can be executed in a batch, wide temperature range. Depending upon various factors semi-continuous, or continuous fashion. The reaction such as the nature of the monomeric reagent(s) em vessel can be a glass vessel, steel autoclave, elongated 70 metallic tube, or other equipment and material employed 5 Helv. Chim. Acta, 18, 1087 (1935). in the polymer art. The order of addition of catalyst and Ber. 66, 1629 (1933). monomeric reagent(s) does not appear to be critical. A See footnote . SZhur. Obshchei Khim, 24, 1439 (1934). Suitable procedure is to add the catalyst to the reaction 9 Ber, 6.8B, 1170 (1935). Zone containing the monomeric reagent(s) and inert or 10 J. Gen. Chem. USSR, 27, 1459 (1957). J. Amer. Chem. Soc. 77, 5601-6 (1955). 75 ganic vehicle, if any. It is highly preferred that the cat 8,021,316 7 8 alyst be added as a suspension or dispersion in an inert essentially characterized by the same recurring unit which normally-liquid organic vehicle such as, for instance, the falls within the scope of Formula II supra. The copoly inert normally-liquid saturated aliphatic and cycloali mers, terpolymers, etc., on the other hand, can contain phatic hydrocarbons, e.g., hexane, heptane, , cyclo as little as 1.0 weight percent, and lower, and upwards hexane, alkylcyclohexane, decahydronaphthalene, and the to 99 weight percent, and higher, of the same recurring like. Incremental addition of catalyst to the reaction Zone unit. Desirable polymers are those in which the Weight can be employed. If desired, the above procedure can be percent of the different recurring units is in the range reversed, that is, the monomeric reagent(s) perse or as a of from about 3 to about 97. In the highly preferred solution or suspension in an inert organic vehicle can be copolymers the weight percent of the two different re added to the reaction zone which preferably contains the 10 curring units is in the range of from about 15 to about 85. catalyst as a suspension or dispersion in an inert normally The polymers obtained by the process of the invention liquid organic vehicle. Also, the catalyst, reagent(s), and are a useful class of polyester compounds. These poly inert organic vehicle, if any, can be added to the reaction mers can range from viscous liquids to tough solids. The zone simultaneously. The reaction zone (be it a closed polymers in the range of from very viscous liquids to rela vessel or an elongated tube) can be fitted with an external 5 tively low molecular weight, wax-like solids are useful in heat exchanger to thus control undue temperature fluctu the preparation of cosmetics, polishes, and waxes, and as ations, or to prevent any possible "run-away' reaction thickening agents for various lubricants. The polymers temperatures due to the exothermic nature of the reaction. can be employed to size cellulosic material or they can be In a continuous operation employing as the reaction Zone used as anti-static agents in the treatment of fibrous ma an elongated tube or conduit, the use of one or a plu 20 terials. They can also be employed as protective coat rality of separate heat exchangers can be conveniently ings, and/or impregnants. The solid polymers are useful used. In a batch operation, stirring means can be pro for the production of various shaped articles such as brush vided for agitating the reaction mixture, as desired. handles, buttons, lamp bases, toys, and the like. The Unreacted monomeric reagent oftentimes can be re solid polymers are useful in the preparation of films by covered from the reaction product by conventional tech 25 such techniques as milling on a two-roll mill, calendering, niques such as by heating said reaction product under solvent casting, and the like. reduced pressure. Removal of unreacted monomeric re In passing, it should be noted that one apparent ad agent(s) and/or inert organic vehicle can be accomplished vantage afforded by the practice of the invention is the by mechanical means such as treatment of the reaction preparation of copolymers, terpolymers, etc., whose physi product in a Marshall Mill and the like. The polymer 30 cal characteristics can be "tailor-made' to fit desired fields product also can be recovered from the reaction product of applications and uses. In other words, by adjusting by Washing said reaction product with an inert normally the concentration of the monomeric charge to a particular liquid organic vehicle, e.g., heptane, and subsequently polymerization system, copolymers, terpolymers, etc., drying same under reduced pressure at slightly elevated which cover a wide spectrum of properties and charac temperatures. Another route involves dissolution in a 35 teristics can be prepared, e.g., soft, rubbery polymers to first inert organic vehicle, followed by the addition of a tough, solid polymers. Second inert organic vehicle which is miscible with the In the illustrative operative examples to follow, the first vehicle but which is a non-solvent for the polymer polymeric product oftentimes is described as possessing product, thus precipitating the polymer product. If de a certain reduced viscosity value. By this term, i.e., sired, the reaction product can be dissolved in an inert 40 "reduced viscosity,” is meant a value obtained by dividing organic vehicle such as acetone, and the like, followed the specific viscosity by the concentration of the polymer by the addition of sufficient water to the resulting solution, in the solution, the concentration being measured in grams said water being miscible with said inert organic vehicle of polymer per 100 milliliters of solvent at a given tem but being a non-solvent for the water-insoluble polymer perature. The specific viscosity is obtained by dividing thereby precipitating the polymer product. Recovery of 45 the difference between the viscosity of the solution and the precipitated polymer can be effected by filtration, de the viscosity of the solvent by the viscosity of the solvent. cantation, etc., followed by drying same as indicated pre The reduced viscosity value is an indication of the mo viously. lecular weight of the polymer. Unless otherwise indi The linear polyester products resulting from the process cated, the reduced viscosity value was determined at of the invention can be characterized by the following 30° C. recurring structural unit: Also, in the illustrative operative example below, the polymerization reaction was generally conducted under an inert atmosphere, e.g., nitrogen. The reaction vessel and O contents, i.e., cyclic ester(s), catalyst, and inert organic / C O 55 vehicle, if any, were maintained, usually under agitation, in a constant temperature, e.g., 90° C., or the reaction y vessel containing the cyclic ester(s) was maintained, usually under agitation, in a constant temperature and wherein the variables R, A, x, y, and z, have the same subsequently the catalyst was added thereto. Since the values as shown in Formula I supra. Of course, the five 60 polymerization reaction, in general, was exothermic a provisos enumerated as (a) through (e) set forth in the rise in temperature was observed, e.g., 140 to 150° C. discussion of Formula I supra likewise apply to the struc In several instances the period recorded was the time tural unit designated as Formula II above. In addition, observed in which the rotation of the mechanical stirrer as indicated previously, the molecular weights of the ceased due to the high viscosity of the contents in the 65 reaction vessel. In most cases the reaction vessel was left polyester products can range from about several hundred in the constant temperature bath for an additional period to about several thousand. The ultimate molecular of time, e.g., about 20 minutes, or longer. Unless other weight and properties of the polyester products will de wise indicated, the examination or description of the poly pend, in the main, upon the choice of the cyclic ester(s) meric product was conducted at room temperature, i.e., and catalyst, the concentration of the catalyst, the oper about 23° C. In general, the conversion of monomer to ative conditions employed, e.g., temperature, etc., the 70 polymer was substantially quantitative. purity of the monomeric reagent(s) and catalyst, the use and amount of an inert normally-liquid organic vehicle, EXAMPLE 1. and the like. (A) To a reaction vessel maintained under a nitrogen It is readily apparent that the linear homopolymers are atmosphere and which contained epsilon-caprolactone, 8,021,816 10 there was charged sodium hydride in an amount so as to rubidium hydride, based on the total weight of methyl give an admixture containing 0.33 weight percent sodium epsilon-caprolactone. The isomeric mixture contains by hydride, based on the weight of said epsilon-caprolactone. weight, approximately 30 percent gamma-methyl-epsilon The reaction vessel then was placed in a constant tem caprolactone, about 30 percent epsilon-methyl-epsilon perature bath maintained at 90° C. Within 77 minutes caprolactone, and about 40 percent beta-methyl- and delta the mechanical stirrer ceased due to the high viscosity of methyl-epsilon-caprolactone. This isomeric lactone mix the contents in the reaction vessel. Thereafter, the poly ture is prepared by reacting a mixture of 2-methyl-, 3 meric product was recovered. There was obtained a methyl-, and 4-methylcyclohexanone with peracetic acid. white, soft, rubbery solid homopolymer which possessed The reaction vessel then is placed in a constant tempera a reduced viscosity value of 0.46 (measured at 0.4 gram O ture bath maintained at 90 C. for a period of 30 minutes. of polymer in 100 ml. of chloroform). Thereafter, the polymeric product is recovered. There is (B) In an analogous manner as above, when beta, obtained a viscous liquid product. gamma-dimethoxy-delta-valerolactone is substituted for (B) In an analogous manner as above, when 2-bromo epsilon-caprolactone and contacted with 1.0 weight per 2-(3'-bromopropyl)-5-hydroxypentanoic acid lactone is 5 substituted for the isomeric mixture of methyl-epsilon cent calcium hydride, there is obtained a solid polymer. caprolactones and contacted with 1.0 weight percent bari EXAMPLE 2. um hydride, substantially similar results are obtained. (A) To a reaction vessel maintained under a nitrogen EXAMPLE 6 atmosphere and which contains epsilon-caprolactone, there is charged sodium hydride in an amount so as to 20 (A) To a reaction vessel maintained under a nitrogen give an admixture containing 0.5 weight percent sodium atmosphere an which contains an isomeric mixture com hydride, based on the weight of said epsilon-caprolactone. posed of a major proportion by weight of gamma-octyl The reaction vessel then is placed in a constant tempera epsilon-caprolactone and a minor proportion by weight ture bath maintained at 90° C. for a period of 45 minutes. of epsilon-octyl-epsilon-caprolactone, there is charged Thereafter, the reaction product is dissolved in chloroform 25 sodium hydride dispersed in hexane in an amount so as and reprecipitated in petroleum ether. There is obtained to give an admixture containing 0.8 weight percent so a solid homopolymer. dium hydride, based on the total weight of octyl-epsilon (B) In an analogous manner as above, when lithium caprolactone. The reaction vessel then is placed in a hydride is substituted for sodium hydride in an amount constant temperature bath maintained at 90° C. for a 30 period of 15 minutes. There is obtained a solid product. so as to give an admixture which contains 1.0 weight (B) In an analogous manner as above, when 2,3,4,5- percent of lithium hydride, based on the weight of epsilon tetrahydrobenzoxepin-2-one is substituted for the isomer caprolactone, essentially the same results are obtained. ic mixture of octyl-epsilon-caprolactones and contacted EXAMPLE 3 with 1.0 weight percent , there is ob (A) To a reaction vessel maintained under a nitrogen 35 tained a solid polymer. atmosphere and which contains epsilon-caprolactone, EXAMPLE 7 there is charged sodium hydride dispersed in cyclohexane in an amount so as to give an admixture containing 0.7 (A) To a reaction vessel maintained under a nitrogen weight percent sodium hydride, based on the weight of atmosphere and which contains delta-valerolactone, there said epsilon-caprolactone. The reaction vessel then is 40 is charged lithium hydride dispersed in petroleum ether placed in a constant temperature bath maintained at 90 in an amount so as to give an admixture containing 0.5 C. Within 5 minutes the mechanical stirrer ceased due weight percent lithium hydride, based on the weight of to the high viscosity of the contents in the reaction vessel. said delta-valerolactone. The reaction vessel then is Thereafter, the polymeric product is recovered. There placed in a constant temperature bath maintained at 90 is obtained a tough, solid product. 45 for a period of 30 minutes. Thereafter, the polymeric (B) In an analogous manner as above, when gam product is recovered. There is obtained a hard, solid na(1-isopropyl-4-methylcyclohexyl)-epsilon-caprolactone homopolymer. ------is substituted for epsilon-caprolactone and contacted (B) In an analogous manner as above, when 3-ethyl-2- with 0.7 weight percent potassium hydride (dispersed in keto-1,4-dioxane is substituted for delta-valerolactone heptane), a viscous liquid product is obtained. and contacted with 1.0 weight percent calcium hydride, 50 a viscous liquid is obtained. EXAMPLE 4 EXAMPLE 8 (A) To a reaction vessel maintained under a nitrogen (A) To a reaction vessel maintained under a nitrogen atmosphere and which contains epsilon-caprolactone, atmosphere and which contains beta-methyl-delta-valero there is charged sodium hydride dispersed in hexane in lactone (redistilled, boiling point 137 C. at 1.5 mm. of an amount so as to give an admixture containing 0.6 Hg; ni of 1.4480) there is charged sodium hydride dis weight percent sodium hydride, based on the weight of persed in cyclohexane in an amount so as to give an ad said epsilon-caprolactone. The reaction vessel then is mixture containing 1.0 weight percent sodium hydride, placed in a constant temperature bath maintained at 90 based on the weight of said beta-methyl-delta-valero C. Within 4 minutes the mechanical stirrer ceased due 60 lactone. The reaction vessel then is placed in a constant to the high viscosity of the contents in the reaction vessel. temperature bath which is maintained at 90° C. for a Thereafter, the polymeric product is recovered from the period of about 30 minutes. Thereafter, the polymeric reaction vessel. There is obtained a white, tough, solid product is recovered. There is obtained a very viscous homopolymer. liquid product. (B) In an analogous manner as above, when gamma 65 (B) In an analogous manner as above, when 3-oxa-6- methyl-delta-isopropyl-epsilon-caprolactone is substituted hydroxy-hexanoic acid lactone is substituted for beta for epsilon-caprolactone and contacted with 1.0 weight methyl-delta-valerolactone and contacted with 0.6 weight percent lithium hydride, there is obtained a viscous liquid percent strontium hydride, essentially similar results are product. obtained. EXAMPLE 5 70 EXAMPLES 9-11 (A) To a reaction vessel maintained under a nitrogen atmosphere and which contains an isomeric mixture of In Examples 9 through 11, various copolymers are pre methyl-epsilon-caprolactone, there is charged rubidium pared by polymerizing an admixture of two lactones in hydride dispersed in petroleum ether in an amount so as the presence of sodium hydride dispersed in petroleum to give an admixture containing 0.5 weight percent 75 ether. The procedure, employed is similar to that set 3,021,316 11 12 forth immediately preceding the operative examples. The tal weight of the lactone feed. The procedure employed pertinent data and results are recorded in Table I below. is similar to that set forth immediately preceding the op Table I

Example - Catalyst Temp, Tine, Description

Number Lactone Charget Concen- C Min. of Copolymer tration 9.------70-epsilon - caprolactone/30 0.5 90 20 Tough solid. -beta-nethyi - delta-valero- - lactone. 10------80 epsilon - caprolactone? 20 0.5 90 20 do. beta - methyl - delta-va erolactone. ll.------85 epsilon - caprolactone/15 0.5 90 20 Waxy solid. beta - methyl-delta-valero- - lactone. iParts by weight. 2 Weight percent catalyst, based on total weight of lactone charge. f NoTE.-Beta-methyl-delta-valerolactone redistilled; B.P.137° C. at 1.5 mm. of Hg; no.32 of 4480. EXAMPLE 12 20 erative examples. The pertinent data and results are (A) To a reaction vessel maintained under a nitrogen at recorded in Table III below. mosphere and which contains zeta-enantholactone, there is charged sodium hydride dispersed in heptane in an Table III amount so as to give an admixture containing 0.5 weight Ratio of Epsi- Description percent sodium hydride, based on the weight of said zeta 25 Example Number lon-Caprolac- Time, of Copol enantholactone. The reaction vessel then is placed in a tone to Delta- min. ymer constant temperature bath maintained at 90° C. for a Waierolactonel period of 5 minutes. Thereafter, the polymeric product 16------20:80 8 White Solid. is recovered. There is obtained a white, solid homopoly 17------80:20. 4 Tough solid. c. 30 - (B) In an analogous manner as above, when 10-hy Ratio is in parts by weight. droxyundecanoic acid lactone is substituted for Zeta enantholactone and contacted with 0.7 weight percent EXAMPLE 18 calcium hydride, essentially similar results are obtained. (A) To a reaction vessel maintained under a nitrogen 35 atmosphere and which contains a mixture of 80 parts by EXAMPLES 13-14 weight of epsilon-caprolactone and 20 parts by weight of In Examples 13 and 14, the procedure employed is mixed dimethyl-epsilon-caprolactone, there is charged so similar to that set forth immediately preceding the opera dium hydride dispersed in hexane in an amount so as to tive examples. The pertinent data and results are re give an admixture containing 0.5 weight percent sodium corded in Table II below. 40 hydride, based on the total weight of the lactone feed. Table II Catalyst Descrip Example Lactone Chargei Catalyst Concen Temp., Time, tion of Number tration 3 o C. Min. Polyester 13------30 zeta-enantholactonef70 epsilon- Nah 0.50 10-Tough, caprolactone. - white solid. 14------20caprolactone. zeta-enantholactonef80 epsilon- CaH, 0.50 O Do, Admixture of two lactones is expressed as parts by weight. Catalyst dispersed in petroleum ether. Weight percent catalyst, based on total weight of lactone charge. NoTE-Zeta-enantholactone redistilled; B.P. 72° C. at 4 mm. of Hg., np of 1.4689. EXAMPLE 1.5 55 The mixed dimethyl-epsilon-caprolactones is an isomeric (A) To a reaction vessel maintained under a nitrogen mixture of beta, gamma-dimethyl- and gamma,delta-di atmosphere and which contains 2-keto-1,4-dioxane, there methyl-epsilon-caprolactones. The reaction vessel then is is charged sodium hydride dispersed in petroleum ether placed in a constant temperature bath maintained at 90 in an amount so as to give an admixture containing 0.5 C. for a period of 3 hours. Thereafter, the polymeric weight percent sodium hydride, based on the weight of 60 product is recovered. There is obtained a soft, solid prod said 2-keto-3,4-dioxane. The reaction vessel then is placed lict, - in a constant temperature bath maintained at 90 C. for (B) In an analogous manner as above, when equal parts a period of about one hour. Thereafter, the polymeric by weight of 12-oxa-15-hydroxypentadecanoic acid lactone product is recovered. There is obtained a solid polymer. and 7-hydroxyheptanoic acid lactone are employed as (B) In an analogous manner as above, when gamma 65 the monomeric feed and contacted with 1.0 weight percent (1-isopropyl-4-methylcyclohexyl)-epsilon-caprolactone is barium hydride (dispersed in heptane), a viscous liquid is substitued for 2-keto-1,4-dioxane and contacted with 1.0 obtained. - weight percent lithium hydride, essentially similar results EXAMPLE 19 are obtained. - (A) To a reaction vessel maintained under a nitrogen 70 atmosphere and which contains a mixture of 50 parts by EXAMPLES 16-17 weight of epsilon-caprolactone and 50 parts by weight of In Examples 16 and 17, various copolymers are pre mixed octyl-epsilon-caprolactones, there is charged sodium pared by contacting, at 90 C., a mixture of epsilon-capro hydride dispersed in cyclohexane in an amount so as to lactone and delta-valerolactone with 0.5 weight percent give an admixture containing 0.5 weight percent sodium sodium hydride (dispersed in heptane), based on the to 75 hydride, based on the total weight of the lactone feed. 8,021,816 13 14 The mixed octyl-caprolactones comprises a major propor EXAMPLE 24 tion by weight of gamma-octyl- and a minor proportion To a reaction vessel maintained under a nitrogen at by weight of epsilon-octyl-epsilon-caprolactones. The mosphere and which contained epsilon-caprolactone, reaction vessel then is placed in a constant temperature there was charged calcium hydride (dispersed in benzene) bath maintained at 90° C. for a period of 1.5 hours. in an amount so as to give an admixture containing Thereafter, the reaction product is dissolved in acetone 0.2 weight percent calcium hydride, based on the weight and reprecipitated in water. There is obtained a waxy of said epsilon-caprolactone. The reaction vessel then copolymer. was placed in a constant temperature bath maintained (B) In an analogous manner as above, when equal parts at 90° C. for a period of 3 hours. Thereafter, the poly by weight of 9-oxabicyclo5.2.2] undecan-8-one and 1,4- 10 mer was recovered. There was obtained a soft, waxy, dioxane-2-one are employed as the monomeric feed and solid homopolymer which possessed a reduced viscosity contacted with 1:5 weight percent calcium hydride (dis value of 0.36 (measured at 0.2 gram of polymer in 100 persed in heptane), essentially similar results are obtained. ml. of chloroform). EXAMPLE 20 Although the invention has been illustrated by the 5 preceding examples, the invention is not to be construed To a reaction vessel maintained under a nitrogen as limited to the materials employed in the above ex atmosphere and which contains equal parts, by weight, of emplary examples, but rather, the invention encompasses 2,4-dimethyl - 4 - methoxymethyl-5-hydroxypentanoic acid the generic area as hereinbefore disclosed. Various modi actone and epsilon-caprolactone, there is charged sodium fications and embodiments of this invention can be made hydride (dispersed in decahydronaphthalene) in an 20 without departing from the spirit and scope thereof. amount so as to give an admixture containing 0.5 weight What is claimed is: percent sodium hydride, based on the total weight of the 1. A process which comprises polymerizing a cyclic monomeric charge. The reaction vessel then is placed in a constant temperature bath maintained at 90° C. for ester characterized by the following formula: a period of 1 hour. Thereafter, the reaction product is 25 O dissolved in acetone and reprecipitated in water. There is obtained a very viscous liquid copolymer. C-O (R-C-R) (R-C-R) EXAMPLE 21 (A), (A) To a reaction vessel maintained under a nitrogen 30 wherein each R, individually, is selected from the group atmosphere and which contains ortho-(2-hydroxyethyl)- consisting of hydrogen, alkyl, aryl, alkaryl, aralkyl, cy phenylacetic acid lactone, there is charged sodium hy cloalkyl, halo, haloalkyl, alkoxyalkyl, alkoxy, and aryloxy; dride dispersed in heptane in an amount so as to give an wherein A is selected from the group consisting of an admixture containing 0.50 weight percent sodium hydride, oxy group, a thio group, and a divalent saturated ali based on the weight of said ortho-(2-hydroxyethyl)-phen 35 phatic hydrocarbon group; wherein x is an integer in ylacetic acid lactone. The reaction vessel then is placed the range of from 1 to 15 inclusive; wherein y is an in a constant temperature bath maintained at 90 C. for integer in the range of from 1 to 15 inclusive; and a period of 30 minutes. There is obtained a soft, Solid wherein z is an integer selected from the group consist polymer. ing of zero and one; with the provisos that (a) the sum (B) In an analogous manner as above, when cis-3-oxa 40 of x-y--z cannot equal three, (b) the total number of bicyclo5.4.0]undecan-4-one is substituted for ortho (2-hy atoms forming the cyclic ester ring does not exceed 18, droxyethyl)phenylacetic acid lactone and contacted with (c) the total number of organic substituents attached 1.0 weight percent calcium hydride, essentially similar to the carbon atoms contained in the cyclic ester ring results are obtained. does not exceed four, (d) from 2 to 4 continuously EXAMPLE 22 45 linked carbon atoms contained in the cyclic ester ring can To a reaction vessel maintained under a nitrogen at represent a portion of a saturated cycloaliphatic hydro mosphere and which contained epsilon-caprolactone, there carbon nucleus which nucleus contains from 4 to 10 was charged sodium hydride (dispersed in benzene) in an carbon atoms, and (e) the four R variables attached to amount so as to give an admixture containing 0.2 weight any two adjacent carbon atoms contained in the cyclic percent sodium hydride, based on the weight of said 50 ester ring can represent a portion of a fused aromatic epsilon-caprolactone. The reaction vessel then was placed hydrocarbon nucleus; with from about 0.001 to about in a constant temperature bath maintained at 90° C. 10 weight percent, based on the total weight of cyclic Within 3 minutes the mechanical stirrer ceased due to ester, of a metal hydride selected from the group con the high viscosity of the contents in the reaction vessel. sisting of lithium hydride, potassium hydride, sodium hy Thereafter, the polymer was recovered. There was ob 55 dride, rubidium hydride, cesium hydride, calcium hydride, tained a tough, solid homopolymer which possessed a strontium hydride, and barium hydride; under substan reduced viscosity value of 0.78 (measured at 0.2 gram of tially anhydrous conditions; for a period of time suffi cient to produce a polymer. polymer in 100 ml. of chloroform). 2. A process which comprises polymerizing an admix EXAMPLE 23 60 ture comprising at least two different cyclic esters which To a reaction vessel maintained under a nitrogen at are characterized by the following formula: mosphere and which contained 50 parts by weight of epsilon-caprolactone and 60 parts by weight of O gamma-octyl-epsilon-caprolactone, there was charged C-0 sodium hydride (dispersed in benzene) in an amount so 65 (R-C-R). (R-C-R) as to give an admixture containing 0.2 weight percent sodium hydride, based on the weight of the total lactone (A), feed. The reaction vessel then was placed in a constant wherein each R, individually, is selected from the group temperature bath maintained at 90° C. Within 3 min consisting of hydrogen, alkyl, aryl, alkaryl, aralkyl, cy 70 cloalkyl, halo, haloalkyl, alkoxyalkyl, alkoxy, and utes the mechanical stirrer ceased due to the high viscosity aryloxy; wherein A is selected from the group consist of the contents in the reaction vessel. Thereafter, the ing of an oxy group, a thio group, and a divalent satu polymer was recovered. There was obtained a soft, semi rated aliphatic hydrocarbon group; wherein x is an crystalline solid which possessed a reduced viscosity value integer in the range of from 1 to 15 inclusive; wherein of 0.81 (measured at 0.2 gram of polymer in 100 ml. of y is an integer in the range of from 1 to 15 inclusive; chloroform). - 75 8,021,316 15 16 and wherein z is an integer selected from the group 13. A process which comprises polymerizing a mono consisting of zero and one; with the provisos that (a) meric lactone admixture comprising delta-valerolactone the sum of x-i-y--z cannot equal three, (b) the total and an alkyl-substituted delta-valerolactone with from number of atoms forming the cyclic ester ring does not about 0.01 to about 3.0 weight percent, based on the exceed 18, (c) the total number of organic substituents total weight of the monomeric lactone feed, of a metal attached to the carbon atoms contained in the cyclic hydride selected from the group consisting of lithium ester ring does not exceed four, (d) from 2 to 4 con hydride, potassium hydride, sodium hydride, rubidium tinuously linked carbon atoms contained in the cyclic hydride, cesium hydride, calcium hydride, strontium hy ester ring can represent a portion of a saturated cyclo dride, and barium hydride; at a temperature in the range aliphatic hydrocarbon nucleus which nucleus contains O of from about -20° C. to about 225 C.; under Sub from 4 to 10 carbon atoms, and (e) the four R vari stantially anhydrous conditions; and for a period of time ables attached to any two adjacent carbon atoms con sufficient to produce a polymer. tained in hite cyclic ester ring can represent a portion 14. The process of claim 13 wherein said metal hy of a fused aromatic hydrocarbon nucleus; with from dride is a group LA metal hydride. about 0.001 to about 10 weight percent, based on the 15. The process of claim 13 wherein said metal hy total weight of cyclic ester, of a metal hydride selected dride is an alkaline earth metal hydride. from the group consisting of lithium hydride, potassium 16. A process which comprises polymerizing a mono hydride, sodium hydride, rubidium hydride, cesium hy meric lactone admixture comprising delta-valerolactone dride, calcium hydride, strontium hydride, and barium and epsilon-caprolactone with from about 0.1 to about hydride; under substantially anhydrous conditions; for a 20 3.0 weight percent, based on the total weight of the mono period of time sufficient to produce a polymer. meric lactone feed, of a metal hydride selected from the 3. A process which comprises polymerizing delta group consisting of lithium hydride, potassium hydride, valerolactone with from about 0.01 to about 3.0 weight sodium hydride, rubidium hydride, cesium hydride, cal percent, based on the weight of said delta-valerolactone, cium hydride, strontium hydride, and barium hydride; at of a metal hydride selected from the group consisting of a temperature in the range of from about -20° C. to lithium hydride, potassium hydride, sodium hydride, about 225 C.; under substantially anhydrous conditions; rubidium hydride, cesium hydride, calcium hydride, stron and for a period of time sufficient to produce a polymer. tium hydride, and barium hydride; at a temperature in 17. The process of claim 16 wherein said metal hy the range of from about -20° C. to about 225 C.; dride is a group A metal hydride. under substantially anhydrous conditions; for a period 18. The process of claim 16 wherein said metal hy of time sufficient to produce a polymer. dride is an alkaline earth metal hydride. 4. The process of claim 3 wherein said metal hydride 19. A process which comprises polymerizing a mono is a group A metal hydride. meric lactone admixture comprising delta-valerolactone 5. The process of claim 3 wherein said metal hydride and an alkyl-substituted epsilon-caprolactone with from is an alkaline earth metal hydride. 3 5 about 0.01 to about 3.0 weight percent, based on the 6. A process which comprises polymerizing an alkyl total weight of the monomeric lactone feed, of a metal substituted delta-valerolactone with from about 0.01 to hydride selected from the group consisting of lithium about 3.0 weight percent, based on the weight of said hydride, potassium hydride, sodium hydride, rubidium alkyl-substituted delta-valerolactone, of a metal hydride hydride, cesium hydride, calcium hydride, strontium hy selected from the group consisting of lithium hydride, 40 dride, and barium hydride; at a temperature in the range potassium hydride, sodium hydride, rubidium hydride, of from about -20° C. to about 225 C.; under sub cesium hydride, calcium hydride, strontium hydride, and stantially anhydrous conditions; and for a period of time barium hydride; at a temperature in the range of from sufficient to produce a polymer. about -20° C. to about 225 C.; under substantially an 20. The process of claim - 19 wherein said metal hy hydrous conditions; for a period of time sufficient to 45 dride is a group A metal hydride. produce a polymer. - 21. The process of claim 19 wherein said metal hy 7. A process which comprises polymerizing epsilon dride is an alkaline earth metal hydride. caprolactone with from about 0.01 to about 3.0 weight 22. A process which comprises polymerizing a mono percent, based on the weight of said epsilon-caprolactone, meric lactone admixture comprising epsilon-caprolactone of a metal hydride selected from the group consisting of 50 and an alkyl-substituted delta-valerolactone with from lithium hydride, potassium hydride, sodium hydride, about 0.01 to about 3.0 weight percent, based on the rubidium hydride, cesium hydride, calcium hydride, stron total weight of the monomeric lactone feed, of a metal tium hydride, and barium hydride; at a temperature in hydride selected from the group consisting of lithium the range of from about -20° C. to about 225 C.; hydride, potassium hydride, sodium hydride, rubidium under substantially anhydrous conditions; and for a 55 hydride, cesium hydride, calcium hydride, strontium hy period of time sufficient to produce a polymer. dride, and barium hydride; at a temperature in the range 8. The process of claim 7 wherein said metal hydride of from about -20° C. to about 225 C.; under sub is a group A metal hydride. stantially anhydrous conditions; and for a period of time 9. The process of claim 7 wherein said metal hydride sufficient to produce a polymer. is an alkaline earth metal hydride. 60 23. The process of claim 22 wherein said metal hy 10. A process which comprises polymerizing an alkyl dride is a group LA metal hydride. substituted epsilon-caprolactone with from about 0.01 to 24. The process of claim 22 wherein said metal hy about 3.0 weight percent, based on the weight of said dride is an alkaline earth metal hydride. alkyl-substituted epsilon-caprolactone, of a metal hydride 25. A process which comprises polymerizing a mono selected from the group consisting of lithium hydride, meric lactone admixture comprising epsilon-caprolactone potassium hydride, sodium hydride, rubidium hydride, 65 and an alkyl-substituted epsilon-caprolactone with from cesium hydride, calcium hydride, strontium hydride, and about 0.01 to about 3.0 weight percent, based on the barium hydride; at a temperature in the range of from total weight of the monomeric lactone feed, of a metal about -20° C. to about 225 C.; under substantially hydride selected from the group consisting of lithium anhydrous conditions; and for a period of time sufficient 70 hydride, potassium hydride, sodium hydride, rubidium to produce a polymer. - hydride, cesium hydride, calcium hydride, strontium hy 11. The process of claim 10 wherein said metal hy dride, and barium hydride; at a temperature in the range dride is a group IA metal hydride. of from about -20° C. to about 225 C.; under sub 12. The process of claim 10 wherein said metal hy stantially anhydrous conditions; and for a period of time dride is an alkaline earth metal hydride. 75 sufficient to produce a polymer. 3,021,316 17 18 26. A process which comprises polymerizing a mono and for a period of time sufficient to produce a polymer. meric lactone admixture comprising an alkyl-substituted 30. A process which comprises polymerizing a mono epsilon-caprolactone and an alkyl-substituted delta-valero meric lactone admixture comprising two different alkyl lactone with from about 0.01 to about 3.0 weight percent, substituted epsilon-caprolactones with from about 0.01 to based on the total weight of the monomeric lactone feed, about 3.0 weight percent, based on the total weight of of a metal hydride selected from the group consisting the monomeric lactone feed, of a metal hydride selected of lithium hydride, potassium hydride, sodium hydride, from the group consisting of lithium hydride, potassium rubidium hydride, cesium hydride, calcium hydride, stron hydride, sodium hydride, rubidium hydride, cesium hy tium hydride, and barium hydride; at a temperature in the dride, calcium hydride, strontium hydride, and barium range of from about -20° C. to about 225 C., under 10 hydride; at a temperature in the range of from about substantially anhydrous conditions; and for a period of -20° C. to about 225 C.; under substantially anhy time sufficient to produce a polymer. drous conditions; and for a period of time sufficient to 27. The process of claim 26 wherein said metal hy produce a polymer. dride is a group LA metal hydride. 28. The process of claim 26 wherein said metal hy 5 References Cited in the file of this patent dride is an alkaline earth metal hydride. UNITED STATES PATENTS 29. A process which comprises polymerizing a mono 2,558,547 Eckey ------June 26, 1951 meric lactone admixture comprising two different alkyl 2,681,360 Vodonik ------June 15, 1954 substituted delta-valerolactones with from about 0.1 to 2,809,958 Barnes et al. ------Oct. 15, 1957 about 3.0 weight percent, based on the total weight of the 20 2,848,441 Reynolds et al. ------Aug. 19, 1958 monomeric lactone feed, of a metal hydride selected from the group consisting of lithium hydride, potassium hy 2,890,208 Young ------June 9, 1959 dride, sodium hydride, rubidium hydride, cesium hydride, 2,921,051 Amborski et al. ------Jan. 12, 1960 calcium hydride, strontium hydride, and barium hydride; FOREIGN PATENTS at a temperature in the range of from about -20° C. to 25 766,347 Great Britain ------Jan. 23, 1957 about 225 C.; under substantially anhydrous conditions; UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3O2l 3 l6 February l3, 1962 Eugene F. Cox et al. It is hereby certified that error appears in the above numbered pat ent requiring correction and that the said Letters Patent should read as corrected below. Column 5 line 50 for "table" read -- table (hydrides of alkali metals) --; same column 5 in footnote 8 for "(1934)" read -- (1954) -- column 10, line 44, for "90'" read -- 90° C. --; columns ll and l?, Table I line l of NOTE thereof, for "n32" read -- n -- same column ll line 68 "substitued" read -- substituted -- column 13 line 63 for "60" read -- 50 -- column 14 lines 32 and 7O and 7l strike out "and aryloxy", each occurrence, and insert instead -- aryloxy, a portion of an aromatic hydrocarbon nucleus which nucleus is fused to the cyclic ester ring and a portion of a saturated cycloaliphatic hydrocarboh nucleus which nucleus contains from 4 to lo carbon atoms and which is fused to the cyclic ester ring --; column l4 line 4l and column 15 line 5, after "lb" each occurrence insert -- and -- column l4 lines 44 to 5l. and column l5, lines 7 to l4 strike out "four (d) from 2 to 4 continuously linked carbon atoms contained in the cyclic ester ring can represent a portion of a saturated cyclocliphatic hydrocarbon nucleus which nucleus contains from 4 to 10 carbon atoms, and (e) the four R variables attached to any two adjacent carbon atoms contained in the cyclic ester ring can represent a portion of a fused aromatic hydrocarbon nucleus", each occurrence and insert instead -- four ; --; column l4 line 6l. Column lT line l8 and column l8 line 3, strike out 'different", each occurrence; column 15 lines 33, 58 and 73, Column l6, lines l4, 29 45 and 6 and column lT line l4, Strike out "a group IA metal hydride", each occurrence, and insert instead -- an alkali metal hydride --. Signed and sealed this 25th day of September l962.

(SEAL) At test : ERNEST W. SWIDER DAVID L. LADD At testing Officer Commissioner of Patent S