3,078,254 United States Patent Office Patiented Feb. 19, 1963

2 dine, 3,5-diethyl-4-vinylpyridine, etc.; similar mono- and 3,078,254 di-substituted alkenyl pyridines and like quinolines; HGH MOELECULAR POYMERS AND RAE HOS acrylic acid esters, such as methyl acrylate, ethyl acrylate; FOR THER PEREPARATION alkacrylic acid esters, such as methyl methacrylate, ethyl Robert P. Zelinski and Henry L. Hsieh, Bariesville, Ck.a., methacrylate, propyl methacrylate, ethyl ethacrylate, butyl assignors to Plai Eips Petroiesia (Coapay, a corpora 5 methacrylate; methyl vinyl ether, vinyl chloride, vinyli tion of Delaware dene chloride, vinylfuran, vinylcarbazole, vinylacetylene, No Drawing. Filed July 20, 1959, Ser. No. 328,053 etc. 20 Claims. (C. 260-45.5) The above compounds in addition to being polym This invention relates to polymers of increased molec 0. erizable alone are also copolymerizable with each other ular weight prepared by reacting terminally reactive poly and may be copolymerized to form terminally reactive mers with compounds containing active halogens. In one polymers. In addition, copolymers can be prepared using aspect the invention relates to solid polymers prepared by minor amount of copolymerizable monomers containing heat curing polymers obtained by reacting polymers con more than one vinylidene group such as 2,4-divinylpyri taining terminal alkali metal atoms with compounds con 5 dine, divinylbenzene, 2,3-divinylpyridine, 3,5-divinylpyri taining active halogens. In still another aspect of the in dine, 2,4-divinyl-6-methylpyridine, 2,3-divinyl-5-ethylpyri vention curing is carried cut in the presence of a conven dine, and the like. tional curing system. The terminally reactive polymers in addition to in As used herein, the term "terminally reactive poly cluding homopolymers of polymerizable vinylidene com mer' designates polymer which contains a reactive group 20 pounds and copolymers of conjugated dienes with vinyli at one or both ends of the polymer chain. dene compounds also include block copolymers, which It is an object of this invention to provide new and are formed by polymerizing a monomer onto the end of useful polymeric materials of increased molecular weight, a polymer, the monomer being introduced in such a and process for their preparation. maniher that Substantially all of the co-reacting molecules Another object of this invention is to provide self 25 enter the polymer chain at this point. In general, the curing polymers from polymers containing terminal alkali block copolymers can include combinations of homopoly metal atoms, and process for their preparation. mers and copolymers of the materials hereinbefore set Still another object of this invention is to provide cured forth. A detailed description of block copolymers con polymers from polymers obtained by reacting polymers taining terminal reactive groups and their method of prep containing terminal alkali metal atoms with compounds 30 aration is set forth in the copending application of R. P. containing two or more active halogens. Zelinski, Serial No. 796,277, filed March 2, 1959. This These and other objects of the invention will become application describes a process for preparing block co imore readily apparent from the following detailed de polymers from monomers included in the following scription and discussion. groups: (1) 1,3-butadiene, 2-methyl-1,3-butadiene, 1,3- The foregoing objects are realized broadly by react 35 pentadiene and vinyl-substituted aromatic hydrocarbons; ing a polymer containing terminal alkali metal atoms (2) vinylpyridines; and (3) vinyl halides, vinylidine ha with an organic compound containing at least two active lides, acrylonitrile, esters of acrylic acid and esters of halogens to obtain a polymer of increased molecular homologues of acrylic acid. The process comprises the weight. steps of initially contacting a monomer selected from In one aspect of the invention the polymer product is 40 those included in groups (1) and (2) with an organo subjected to heat whereby molecules of said polymer lithium compound in the presence of a diluent selected react with each other to form a cured polymer. from the group consisting of aromatic, parafiinic and In another aspect of the invention curing of the poly cycloparaffinic hydrocarbons so as to form a polymer mer product is carried out in the presence of a conven block; and, after polymerization of substantially all of tional curing system. 45 the selected monomer, contacting the aforementioned The monomers which can be employed in the prepara catalyst in the presence of the polymer block initially tion of polymers containing terminal alkali metal atoms formed and the hydrocarbon diluent with a monomerse include a wide variety of materials. The preferred mono lected from those included in groups (1), (2) and (3) mers are the conjugated dienes containing from 4 to 12 when the initial monomer is selected from group (1) and carbon atoms and preferably 4 to 8 carbon atoms, such 50 with a monomer selected from those included in group as 1,3-butadiene, isoprene, piperylene, methylpentadiene, (3) when the initial monomer is selected from group (2), phenylbutadiene, 3,4-dimethyl-1,3-hexadiene, 4,5-diethyi the monomer selected being different from the monomer 1,3-octadiene, etc. In addition, conjugated dienes con employed in the initial contacting. taining reactive substituents along the chain can also be The terminally reactive polymers are prepared by con employed, such as for example, halogenated dienes, such 55 tacting the monomer or monomers which it is desired to as chloroprene, fluoroprene, etc. Of the coniugated di polymerize with an organo alkali metal compound. The enes the preferred material is butadiene, with isoprene organo alkali metal compounds preferably contain from and piperylene also being especially suitable. In addi 1 to 4 alkali metal atoms, and those containing 2 alkali tion to the conjugated dienes other monomers which can metal atoms are more often employed. As will be ex be employed are aryl-substituted olefins, such as styrene, 60 plained hereinafter, lithium is the preferred alkali metal. various alkyl styrenes, paramethoxystyrene, vinylnaphthal The organo alkali metal compounds can be prepared ene, vinyltoluene, and the like; heterocyclic nitrogen-con in several ways, for example, by replacing halogens in taining monomers, such as pyridine and allinoline deriva an organic halide with alkali metals, by direct addition tives containing at least 1 vinyl or alphamethyl-vinyl of alkali metals to a double bond, or by reacting an group, such as 2-vinylpyridine, 3-vinylpyridine, 4-vinyl 65 organic halide with a suitable alkali metal compound. pyridine, 3-ethyl-5-vinylpyridine, 2-methyl-5-vinylpyri The organo alkali metal compound initiates the po. 3,078,254 3. 4. lymerization reaction, the organo radical being in ample, of the condensed ring aromatic compounds the corporated in the polymer chain and the alkali metal lithium-anthracene adduct is preferred, but the adducts of being attached terminally on at least one end of the lithium with naphthalene and biphenyl can be employed polymer chain. When employing polyalkali metal con with good results. Of the compounds of alkali metals pounds an alkali metal is attached terminally at each with polyaryl-substituted ethylenes, the preferred ma end of the polymer chain. The polymers in general will terial is 1,2-dilithio-1,2-diphenylethane (lithium-stilbene be linear polymers having two ends; however, polymers adduct). Ordinarily the organo dialkali metal com containing more than two ends can be prepared within pounds are more effective than others in promoting the the scope of the invention. The general reaction can be formation of the terminally reactive polymers. The illustrated graphically as follows: O organo dialkali metal compounds which have been set forth as being preferred, are those which when prepared Y-R-Y -- XCH - Y-R(CH-Y contain a minimum of the monoalkali metal compound. Organoalkali Butadiene The amount of initiator which can be used will vary metal compound depending on the polymer prepared, and particularly the 5 molecular weight desired. Usually the terminally reac O tive polymers are liquids, having molecular weights in Y- CAHs) -R- I CH6 x-n-Y the range of 1000 to about 20,000. However, depending on the monomers employed in the preparation of the or combinations thereof. polymers and the amount of initiator used, semi-solid and A specific example is: 20 solid terminally reactive polymers can be prepared having molecular weights up to 150,000 and higher. Usually the initiator is used in amounts between about 0.25 and about 100 millimoles per 100 grams of monomer. Formation of the terminally reactive polymers is gen In the specific example 1,4-addition of butadiene is erally carried out in the range of between -100 and shown; however, it should be understood that 1,2-addi --150° C., preferably between -75 and --75° C. The tion can also occur. particular temperatures employed will depend on both While organo compounds of the various alkali metals the monomers and the initiators used in preparing the can be employed in carrying out the polymerization, by polymers. For example, it has been found that the far the best results are obtained with organolithium 30 organolithium initiators provide more favorable results compounds which give very high conversions to the at elevated temperatures whereas lower temperatures are terminally reactive polymer. With organo compounds required to effectively initiate polymerization to the de of the other alkali metals, the amount of monoterminally sired products with the other alkali metal compounds. reactive polymer, that is, polymer having alkali metal at The amount of catalyst employed can vary but is pref only one end of the chain is substantially higher. The erably in the range of between about 1 and about 30 alkali metals, of course, include sodium, potassium, lith millinoles per 100 grams of monomers. It is prefered ium, rubidium, and cesium. The organic radical of the that the polymerization be carried out in the presence organo alkali metal compound can be an aliphatic, cy of a suitable diluent, such as benzene, toluene, cyclohex cloaliphatic or aromatic radical. For example, mono-, ane, methylcyclohexane, xylene, n-butane, n-hexane, n di- and polyalkali metal substituted hydrocarbons can 40 heptane, isooctane, and the like. Generally, the diluent is be employed including methyllithium, n-butyllithium, n Selected from hydrocarbons, e.g., paraffins, cycloparaffins, decyllithium, phenyilithium, napthyllithium, p-tolyllith and aromatics containing from 4 to 10 carbon atoms per ium, cyclohexyllithium, 4-butylphenylsodium, 4-cyclo molecule. As stated previously, the organodilithium com hexylbutylpotassium, isopropylrubidium, 4-phenylbutyl pounds are preferred as initiators in the polymerization cesium, 1,4-dilithiobutane, 1,5-dipotassiopentane, 1,4-di 45 reaction since a very large percentage of the polymer sodio-2-methylbutane, 1,6-dilithiohexane, 1,10-dilithiodec molecules formed contain two terminal reactive groups, ane, 1,15-dipotassiopentadecane, 1,20 - dilithiosicosane, and also the polymerization can be carried out at normal 1,4-disodio-2-butene, 1,4-dilithio-2-methyl-2-butene, 1,4- room temperatures. This is not to say, however, that dilithio-2-butene, 1,4-dipotassio-2-butene, dilithionaphtha other organo alkali metal initiators cannot be employed; lene, disodionaphthalene, 4,4'-dilithiobiphenyl, disodio 50 however, usually more specialized operation or treatment phenanthrene, dilithioanthracene, 1,2-dilithio-1,1-diphen is required with these materials, including low reaction ylethane, 1,2-disodio-1,2-triphenylpropane, 1,2-dilithio temperatures. Since it is desirable to obtain a maximum 1,2-diphenylethane, 1,2-dipotassiotriphenylethane, 1,2-di yield of terminally reactive polymer, it is within the Scope lithiotetraphenylethane, 1,2-dilithio-1-phenyl-1-naphthyl of the invention to use separation procedures, particu ethane, 1,2-dilithio-1,2-dinaphthylethane, 1,2-disodio-1,1- larly with alkali metal initiators other than lithium com diphenyl-2-naphthylethane, 1,2-dilithiotrinaphthylethane, pounds, to separate terminally reactive polymer from 1,4-dilithiocyclohexane, 2,4-disodioethylcyclohexane, 3,5- the polymer product. dipotassio-n-butylcyclohexane, 1,3,5-trilithiocyclohexane, The terminally reactive polymers prepared as herein 1-lithio-4-(2-lithiomethylphenyl)butane, 1,2-dipotassio-3- before described contain an alkali metal atom on at least phenylpropane, 1,2-di(lithiobutyl)benzene, 1,3-dilithio-4- 60 one end of the polymer chain and the organo radical of ethylbenzene, 1,4-dirubidiobutane, 1,8-dicesiooctane, the initiator is present in the polymer chain. These com 1,5,12-trilithiododecane, 1,4,7-trisodioheptane, 1,4-di(1,2- pounds can be converted to polymers of higher molecular dilithio-2-phenylethyl)benzene, 1,2,7,8-tetrasodionaphtha Weight by reaction or coupling with organic compounds lene, 1,4,7,10-tetrapotassiodecane, 1,5-dilithio-3-pentyne, containing two or more active halogen atoms. The active 1,8-disodio-5-octyne, 1,7-dipotassio - 4 - heptyne, 1,10-di 65 halogen containing compounds are those in which each cesio-4-decyne, 1,11-dirubido-5-hendecyne, 1,2-disodio 1,2-diphenylethane, dilithiophenanthrene, 1,2-dilithio-tri halogen is attached to a carbon atom which is alpha to an phenylethane, 1,2-disodio-1,2-diphenylethane, dilithio activating group which is inert with respect to the alkali methane, 1,4-dilithio - 1,1,4,4-tetraphenylbutane, 1,4-di metal atoms in the terminally reactive polymer, for ex lithio-1,4-diphenyl-1,4-dinaphthylbutane, and the like 70 ample, groups such as an ether linkage, a carbonyl group, While the organo alkali metal initiators in general a double bond can be employed, certain specific initiators give better results than others and are preferred in carrying out the preparation of the terminally reactive polymers. For ex 75 a carbon atom in the aromatic ring, and the like. The 3,078,254 5 6 active halogen containing compounds can contain fluorine, chloromethyl 1-chloropropyl ether, bis(1-iodoamyl) ether, chlorine, bromine or iodine, or mixtures of these mate bis (1 - chlorodecyl) ether, hexyl 1,1-dichloroheptyl ether, rials; however, chlorine, bromine and iodine compounds 1-chloro-n-butyl 1,1-dichloro-n-butyl ether, bis(1,1-di are preferred, and more particularly compounds contain bromodecyl) ether, 1,1-difluoroethyl 1-fluoroheptyl ether, ing chlorine. Substituents which are inert with respect to bischloro(ethoxy) methyl ether, bis(1-bromo (2-propyl) the lithium atoms in the terminal reactive polymer can ethyl ether, difluoromethyl 1-fluoro(3-ethoxy) propyl also be present in the active halogen containing com ether, bischloro(vinyloxy) methyl ether, bis 1-iodo-(4- pounds. Illustrative of these substituents are groups such vinyloxy) n-butyl ether, 1-bromo (2-vinyloxy)ethyl 1, 1 as alkoxy, vinyloxy, tertiary amine and the like. In addi dibromopropyl ether, bis1 - chloro (5-vinyloxy) octyl tion the active halogen containing compounds can contain O ether, bischloro(N,N-dimethylamino) methyl ether, di various hydrocarbon groups, such as alkyl, cycloalkyl, bromomethyl 1 - bromo-4-(N,N-dimethylamino)n-butyl aryl, aralykyl, and alkaryl, and can have a total of 20 car ether, bis1-iodo-6-(N,N-diethylamino) hexyl ether, 2,2- bon atoms. dibromo-3-decanone, 3,5,5-trichloro-4-octanone, 2,4-di The following reactions are illustrative of examples of bromo-3-pentanone, 1 - chloromethyl-4-(1-chloro-n-prop the coupling reaction in which P represents the polymer 5 yl)benzene, 1,3,5-tri(bromomethyl)benzene, 1,4-di-chlo chain. ro-2-hexane, 4,4-di-chloro-2-heptene, 1,1-dibromo-4-chlo ro-2-pentene and 2,5,6,9-tetrachloro-3,7-decadiene. (1) H H In carrying out the invention the active halogen con 3Li-P-Li) -- 2C--O--Cl ra-a-3 taining compound is added either per se or as a solution E. B 20 to the unquenched polymer solution. By "unquenched polymer' is meant polymer which has not been treated | | | || with any type of reagent to inactivate the catalyst. Suit Li-P- -0--P--0--P-Li -- 4LiCl able solvents for the active halogen containing compound H H h H include materials which are employed as diluents in the 25 preparation of the polymers containing terminal alkali (2) H E metal atoms. Reaction of the active halogen containing 2(Li-P-L) -- 2B:----Br Head compound with the terminally reactive polymer can be H H carried out over a wide range of temperature. In gen eral, a suitable reaction temperature is from -100 to H H H Q H 30 - 150 C. preferably in the range of from -75 to --75 L-P----P--- Br + 3LiBr C. The particular reaction temperature employed is de h it it it termined by the nature of the polymer being treated and by the active halogen containing compound which is used. (3) H. H. E. H. The amount of active halogen containing compound 3Li-P-Li -- 2Cl-C-C=d-d-: --H su-d 35 which is provided in the reaction system will depend on b E. the type of product desired. If the terminally reactive H polymer contains two alkali metal end groups, maximum L-p--P- -P-Li reaction or coupling of the polymer with the active E-C H-5 halogen containing compound is obtained by providing -- 4LiCl 4) one equivalent of halogen per equivalent of alkali metal - E in the polymer. An excess of halogen containing com pound will give a product with active halogen end groups while the use of less than one equivalent of halogen per equivalent of alkali metal will yield a product with alkali 45 metal end groups. The quantity of active halogen con (4) C. E. taining compound used is generally in the range of from 2Li-P-Li -- 3H-(-)-o-c-Cl mn-3 0.5:1 to 5:1 equivalents based on the original initiator h charge. Usually the polymer product is hydrolyzed or H-6 reacted with a material such as an acid, which is capable 50 of replacing alkali metals with hydrogens. H The polymer products of this invention are in some in h stances self-curing, that is, they can be cured by heating C EI H H C. E. alone without the use of auxiliary curatives. The curing H-0-0-0--d-p-b-o-c-P-3-O-(-)-H occurs by reaction of reactive groups in the polymers with double bonds in the same or different polymer chains, the h is H-5-H k l l () degree of curing being determined by the amount of reac H-5 b C-H + LiCl tive groups in the polymer. For example, cross-linking H-5 H-5 8-H can occur through activating and functional groups such h H-5 h as carbonyl groups, double bonds, vinyloxy groups, etc. 3) Also, if an excess of the active halogen containing com h pound is employed or if said compound contains more (5) P than two active halogens, cross-linking can take place by reaction of the halogen with double bonds. H i-- --it The curing reaction is usually carried out by heating the 2L-P-L) +2B-C-O-C-Br -Y b b -- 4LiBr 65 polymer to temperatures in the range of between about it h H–C–H H–C–H 100 and about 500 F. and preferably between about 200 and about 400 F. The time required for curing depends on the temperature, the particular polymer being cured Specific active halogen containing compounds which can and the degree of curing desired. Usually curing is car be employed in carrying out the invention include the 70 following: bis(chloromethyl)ether, bis (1 - bromoethyl) ried out over a period ranging from as low as 2 minutes ether, 1,3-dichloro-2-propanone, 1,5-dichloro-2,4-pentane to as high as 24 hours or higher. As desired prior to dione, 1,4-bis(chloromethyl)benzene, 1,4 - dichloro-2- curing polymers can be compounded with suitable rein butene, bis(bromomethyl) ether, methyl dichloromethyl forcing agents and fillers well known in the industry such ether, bis(1-fluoropropyl) ether, bis(iodomethyl) ether, 75 as carbon black and mineral fillers. 8,078,254 7 8 The following reactions illustrate the curing reaction: If the active halogen containing compound has three

(I) O. H. heat 2 HICH-CH=CH-CH-)--C--Cl r-all E. H HICH-CH=CH-CH)----HII ( II O HCH-CH=CH-CHCH-CH-CHC1-CHCH-CH| -- CH-CH)-----Cl H

where n can vary from 0 to x-1. active halogen atoms, the resultant polymer will have a The above polymer has been hydrolized to replace the Y shape with a molecular weight approximately triple that Li atoms at one end of the chain with H. This step is of the starting material. Polymers which contain alkali desirable to product the self-curing polymer. 20 metal atoms at each end of the polymer chain are con

(2) CH-CH=CH-CH) B - B-C-Br heat 2 O p relaxes H-i-H E-C- |-CH-CH=CH-CH,- Br 8-0-5 - l H &H, CEth | -- -

Br B -- ICH-CH=CH-CH-CH-C-E-ICH-CH=CH-CH-)-to s E. I-, H--H H-b-H |-CH-CH=CH-CH-)- where n can vary from 0 to x-1. verted to high molecular weight linear products by treat In combination with heat curing it is within the scope 55 ment with compounds containing two active halogen of the invention to provide conventional auxiliary curing atoms, the amount of the treating agent employed con agents such as sulfur, oxygen, organic peroxides and hy trolling the length of the polymer chain. droperoxides, bis-azobutyronitrile and diazo thioethers. In the preferred method of this invention liquid and Materials which are free radical generators are ordinarily semi-solid polymers are converted to rubbery and plastic regarded as being useful as curatives in the systems. A 60 products and polymers which are originally rubbery or particularly effective curing agent is dicumyl peroxide. solid are further cured. When operating in accordance Other materials well known as rubber curing agents in with the invention a wide variety of products can be ob clude Santocure (N - cyclohexyl - 2 - benzothiazylsuifen tained to give materials which are suitable as adhesives, amide), Altax (benzothiazyldisulfide), methyl Tuads (tet potting compounds, tread stocks and also for the manu 65 facture of many types of molded objects. Plastic prod ramethylthiuram disulfide) and N,N-dimethyl - S-tert ucts which have a high impact strength frequently have butylsulfenyldithiocarbamate. The auxiliary curing a low tensile strength, however materials prepared in ac agents can be used when a tighter or greater degree of cordance with the present invention have both high im cure is desired than can be obtained by heat alone. pact and high tensile strength. Another outstanding char Various types of polymers can be produced by the 70 acteristic of the polymers of this invention is that they method of this invention. If the polymer chain has only are clear and colorless. In addition rubbery polymers of one carbon-lithium bond and the active halogen contain this invention, obtained after treatment of the terminally ing compound contains two active halogen atoms, the reactive polymer with the active halogen containing com resultant polymer is linear with the molecular weight pound, then compounded and cured have lower heat being approximately double that of the starting material. 5 build-up properties than untreated rubbers. 8,078,254 9 O The following examples are presented in illustration of ing table shows inherent viscosity and gel data before and the invention: after coupling with bis(chloromethyl) ether:

Example I Inherent Gel, Conversion, Inherent Gel, Run viscosity percent? percent viscosity percent A reactor, fitted with a condenser and stirrer and main before after tained under a prepurified nitrogen atmosphere, was coupling 1 coupling charged with the following ingredients: 1----- 2.76 0 96 9.01 5 Diethyl ether, anhydrous---- 1,000 ml. 2----- 2.69 0 Quantitative 7.70 O 3----- 2.20 0 Quantitative 7.06 O Tetrahydrofuran------. 100 m. 10 4----- 2.17 0 Quantitative 6.88 0. Lithium wire, low sodium--- 6.9 grams (1.0 gram atom). 5----- .93 0 99 4.0 O trans-Stilbene (1,2-diphenyl One tenth gram of polymer was placed in a wire cage ethylene)------36.0 grams (0.20 mole). made from 80 mesh screen and the cage was placed in 100 ml. of toluene contained in a wide-mouth, 4-ounce bottle. After standing at roona temperature (approximately 25 C.) 15 for 24 hours, the cage was removed and the solution The mixture was refluxed gently for one hour after was filtered through a sulfur absorption tube of grade C porosity to remove any solid particles present. The result which it was siphoned into quart bottles which were then ing solution was run through a Medalia-type viscometer capped and pressured with nitrogen. The concentration supported in a 25 bath. The viscometer was previously calibrated with toluene. The relative viscosity is the ratio of 1,2-dilithio-1,2-diphenylethane was assumed to be of the viscosity of the polymer solution to that of toluene. equivalent to half the total alkalinity and was determined The inherent viscosity is calculated by dividing the natural logarithm of the relative viscosity by the weight of the by titration of two milliliter samples with aqueous 0.0497 original sample. N hydrochloric acid using phenolphthalein as the indi Determination of gel was made along with the inherent viscosity determination. The wire cage was calibrated for cator. The concentration of the 1,2-dilithio-1,2-diphenyl toluene retention in order to correct the weight of swelled ethane determined by this method was 0.199 molar. gel and to determine accurately the weight of dry gel. The The 1,2-dilithio-1,2-diphenylethane was used as the ini 25 empty cage was immersed intoluene and then allowed to tiator in a series of polymerizations for the preparation Adrain piece three of foldedminutes quarter-inch in a closed hardwarewide-mouth, cloth two-ounce in the bottombottle. of Styrene-butadiene-styrene block copolymers. One run Theof the bottle bottle containing supported the thecage cage was withweighed minimum to the contact.nearest was made which contained no butadiene monomer. 0.02 gram during a minimum three-minute draining period Polymerization recipes were as follows: after which the cage was withdrawn and the bottle again 30 twoweighed weighings to the is nearest the weight 0.02 gram.of the Thecage, differenceplus the toluenein the retained by it, and by subtracting the weight of the empty cage from this value, the weight of toluene retention is found, i.e., the cage calibration. In the gel determination, after the cage containing the sample had stood for 24 hours Recipes in toluene, the cage was withdrawn from the bottle with the aid of forceps and placed in the two-ounce bottle. The same 35 procedure was followed for determining the weight of swelled 2 3 4. 5 gel as was used for calibration of the cage. The weight of swelled gel was corrected by subtracting the cage calibration. Butadiene, parts by weight------20 5 10 5 O The cage, after removal from the two-ounce bottle, was Styrene, parts by weight.-- 80 85 90 95 00 placed in an aluminum weighing dish of known weight and Cyclohexane, parts by weight..... 1,170 1,170 1,170 1,170 1,170 the cage and dish were placed in a vacuum drying oven at 1,2-dilithio-1,2-diphenylethane, cool70-80° to C.room for onetemperature hour after and which weighed. they wereSubtracting allowed theto Innoles------0.7 0.7 0.7 0.7 0.7 40 sum of the weights of the aluminum dish and the cage from Temperature, C.- - 50 50 50 50 50 the latter weighing gave the weight of the gel which was Time, hours.------4. 4. 4. 4 2 finally corrected for solution retention on the cage and for soluble polymer remaining within the gel structure.' The increase in inherent viscosity after treatment with Polymerizations were effected in quart bottles. The 45 bis(chloromethyl) ether is evidence of the coupling re cyclohexane employed was process grade. It was dried action which occurred. by first passing it over activated alumina and then by Impact strength, tensile yield, tensile break, and elonga countercurrent scrubbing with prepurified nitrogen. It tion were determined on the five plastic products obtained was charged to the bottle first after which nitrogen was after coupling with bis(chloromethyl) ether. Similar passed through it for 5 minutes at the rate of 3 liters per 50 properties were also determined on four commercial poly minute. Butadiene was then charged (first four runs) styrenes. Results were as follows: followed by the 1,2-dilithio-1,2-diphenylethane and tem Tensile Tensile Elonga perature of the mixture was held at 50 C. for two hours yield, break, tion Impact 8 p.s.i.4 p.s.i.5 break, to allow the butadiene to polymerize. Styrene was added ft. lbs.fin comp. comp. percent 6 and polymerization was continued for another two hours. 55 molded molded coup. A 20-milliliter sample was withdrawn from each bottle Inolded and the polymer was coagulated with isopropanol. Ap

Product from run proximately one percent by weight of 4,4'-thio-bis(6-tert 1,880 1,827 33 butyl-meta-cresol), based on the butadiene charged, or 2,883 2,740 7 3,927 3,927 8 not less than 0.1 weight percent based on the total 60 5,750 5,750 3 polymer, was added to the wet crumb and kneaded in 4,130 4,130 2 by hand. The samples were vacuum dried. All products Commercial polystyrene: were white plastics. StyronLustrex (A)------(high impact 0.56 3,063 2,853 59 grade) (B)------0.65 2,870 2,493 5 Each of the remaining unquenched polymer solutions Styron (extra high in was treated with a 0.3 molar solution of bis(chlorometh pact grade) (B)------3.98 1,527 1,580 59 yl) ether in cyclohexane using 0.7 millimole per hundred Dylene (C)------0.8 3,290 3,290 17 parts monomers charged. This amount was equivalent Nore-(A) Monsanto; (B) Dow; (C) Koppers. to the quantity of 1,2-dilithio-1,2-diphenylethane em 3 Impact strength was determined by the Izod impact resistance test, ASTM D256-54. ployed. After a 2-hour reaction period at 50° C., the 45 6 Determined by ASTM D412-51T except for the cross-head speed. polymers were coagulated with isopropanol, 4,4'-thio 70 Test specimens were died out of a compression molded slabusing a type bis(6-tert-butyl-meta-cresol) was added to the wet crumb C die for rubber specimens. These specimens measured 4.5' long, 0.250' wide in the flat test section, and 0.06' thick. Stress-strain properties in amounts hereinbefore given, and the products were were obtained at 732C. In Example I, the cross-head speed for Run 1 vacuum dried. All were white plastics. The products was 0.50' per minute and for Runs 2, 3, 4 and 5 it was 0.05'per minute. Cross-head speed for Lustrex and Dylene was 0.05 per minute and for were tough solids after the bis(chloromethyl) ether treat the two Styron samples it was 0.50' perminute. The cross-head speed ment but there was no change in appearance. The follow 75 for the products in Example II was 0.50' per minute. 3,078,254 11. 12 Reference to the foregoing data reveals that plastic The marked increase in inherent viscosity after treat products which have an impact strength similar to some ment with bis(chloromethyl) ether is evidence that cou of the commercial polystyrenes tested having a much pling occurred. The products were gel free and were, higher tensile strength than the commercial products. It therefore, not crosslinked. is possible, when operating in accordance with the present 5 The following physical data were obtained on the two process, to produce plastic products which have both high plastic products which resulted from coupling with bis impact strength and high tensile strength. (chloromethyl) ether: Example II Two polymerization runs were made for the production of 37.5-25-37.5 and 40-20-40 styrene-butadiene-styrene 10 block copolymers using the 1,2-dilithio-1,2-diphenyleth ane initiatorinf described in Example I. Polymerization Run Ft. lbs.fin. Tensileyield, Tensilebreak, break,Elongation per recipes were as follows: p.s. i. Comp. p.s. i. comp. cent comp. molded 4 molded In olded Recipes 15.------1B------ai, 10 1, 120 1,070 69 2 2B------1790 1,773 43

Butadiene, parts by Weight------25 20- s Sample was highly flexible and did not break. Styrene, parts by weight.------75 89 20 56 Same as in Example I. Cyclohexane, parts by weight------1,70 l, 170 1,2-dilithio-1,2-diphenylethane, millinole 0.8 0.7 Temperature, C------50 50 Time, hours.------4 4 - The- procedure - described - - - in- Example- - I -was followed - Examplep III with the butadiene being charged first and allowed to po- 25 1,2-dilithio-1,2-diphenylethane was prepared in a quart lymerize for two hours prior to addition of the styrene. beverage bottle using the following recipe: At the end of the polymerization, a 20-milliliter sample was withdrawn from each bottle, coagulated with isopro- trans-Stilbene------14.4 grams (0.08 mole). panol, 4,4'-trio-bis(6-tert-butyl-meta-cresol) was added, Lithium wire, low sodium-- 2.8 grams (0.4 gram atom). and the products were vacuum dried. They were white 80 Diethyl ether, anhydrous -- 400 ml. plastics. Tetrahydrofuran, anhy The remaining unquenched polymer solutions were drous?------40 m. treated with a 0.3 molar solution of bis(chloromethyl) i Dried over sodium. ether in cyclohexane. Time allowed for the reaction was Dried by distillation from lithium aluminum hydride. 24 hours and the temperature was 50° C. White solid 35 products were obtained after coagulation of the poly mers with isopropanol and drying them in vacuo. The following table shows quantities of materials charged and The reactants were agitated at 30° C. for three hours. inherent viscosity and gel data: The 1,2-dilithio-1,2-diphenylethane was used as the ini tiator in a series of polymerizations for the production Run Recipe 1.2-dithio-Bis(chloro-3:52. ES5 Conver-say Inherent Gel, of styrene-butadiene-styreneo (25-50-25 and 15-70-15) yethane, ether, percent viscosity percenti and butadiene-styrene-butadiene (25-50-25 and 15-70 MHM a MEM a 15) blockr copolymers. The procedure employed was 1A.----- 0.8 ------100 2.17 0 45 similar to that of the preceding examples with the solvent 1B------9.8 0.8 98.0 8.2 O (cyclohexane) being charged first, followed by the initial 3. 87 ------6.7 g: 5 8 monomer charge and then the initiator. The table which follows shows when the ingredients were charged and a Millinoles per 100 parts non-oners. the final recipe in each run. Bis(chloromethyl) ether was 2 SameSame asas inin ExampleExample I.I. 50 used as the coupling- agent in each run.

Parts by weight Millinoles Buta- Sty- Cyclo-1,2-dilithio-Bis(chloro-- Temp,C. Time,hours diene rene hexane 1,2-diphen- methyl) ylethane ether

IRun A: A-1, initial charge ------50 ------1, 170 50 2 Increment No. 1 ------50------50 2 A-2, recipe after increment added a--- 50 50 1, 170 50 4. Increment No. 2"------i) 50 16 A3, final recipe------50 50 1, 170 0 10 50 20 Run B: B-1, initial charge a-- - 50 1, 170 10 ------50 2 Increment No. 1 a 50 2 B-2, recipe after inc 5) 4. Increment No. 2 a. 50 16 B-3, final recipe------50 20 Run C: C-1, initial charge ------70 50 2 Increment No. 1 ------50 2 C-2, recipe after increment added a... 70 30 1, 170 i0 ------50 4. Increment No. 2"------10 50 6 C-3, final recipe------70 30 , 170 10 0 50 20 Run D: D-1, initial charge ------30 1, 170 50 2 Increment No. 1 "------70 ------50 2 D-2, recipe after increment added a 70 30 1, 170 50 4 Increment No. 2"------10 50 16 D-3, final recipe------O 30 1, 170 O 10 50 20 Given in terms of amount in final recipe. 8,078,254 3. 4. Samples from each initial polymerization and also after mer solutions and the reactions were continued another the monomer increment was added were withdrawn, co two hours at the same temperature. The polymers were agulated with isopropanol, vacuum dried, and conver all coagulated with isopropanol and vacuum dried. The sion and inherent viscosity were determined. Refractive following table shows the initiator level, amount of bis index was determined in some cases. The remaining (chloromethyl) ether added, conversion, and results of unquenched polymer solutions were treated with bis(chlo inherent viscosity and gel determinations: romethyl) ether, coagulated with isopropanol, vacuum dried, and conversion, inherent viscosity, refractive index, 1,2-dilithio- Bis(chio- Colaver Run I,2-diphen-i romethyl) sion, Inherent Gel, and Mooney values (ML-4 at 212 F.) were determined. ylethane, ether, percent viscosity 1 percent The following table shows these results: 0. Inmoles a mmoles a

Conver- Inher- ML-4 Re 2 100 2.29 0 Recipe sion, entwis- at 212 fractive Polymer appearance ... 2 77 3.49 0 percent cosity i F. 7 index at i. 100 2.04 O 25° C. 8 l, i. 99.8 5.08 0. 1.0 ------100 2.37 0.

1.0 1.0 99.6 5.67 0 OO 0.42 ------1.5123 Liquid. 0.91------100 3.10 O 9. Sticky, semi-solid. 0.9 0.9 00 6.42 0 88.5 0.90 42 i. 5515 Firm, clear solid; rubbery. a Per 100 parts monomers. 00 0.11------Solid 20 12 Same as in Example I. 99.2 0.21 ------Sticky, semi-solid. 96.5 0, 65 25 i. 5531 Firm, clear solid; The products obtained by treatment of the polymers rubbery. with bis(chloromethyl)ether were tough, gel free, plastics 99.3 Liquid. which had a much higher inherent viscosity after treat 99, 6 Sticky, semi-solid, 92.2 Tough, clear Solid; 25 ment with bis(chloromethyl) ether. rubbery. Example V 00 0.09 ------Solid. 97.7 0.26 ------1. 5364 Sticky, semi-solid The 1,2-dilithio-1,2-diphenylethane described in Ex 93,5 0.84 13 1.5368 Tough, clear solid; ample IV was employed as the initiator for the prepara rubbery. tion of a series of 10/90 butadiene-styrene random co 30 polymers. Variable initiator levels were used in the runs. 1 Same as in Example I. The polymerization recipe was as follows: 78 TheDetermined sample bywas ASTM placed D927-55T.on the prism of a Model 808 Spencer Lens Company refractometer. The refractive index was determined at 25° C. Butadiene, parts------10 The refractive index values demonstrate that styrene is Styrene, parts------90 present in the block polymers. Treatment of the un Cyclohexane, parts------1,170 quenched block polymer with bis(chloromethyl) ether Tetrahydrofuran, parts------2 in each case gave a rubbery product whereas without this 1,2-dilithio-1,2-diphenylethane, mmoles.------Variable treatment the products were sticky, semi-solids. Example IV Polymerization was effected at three initiator levels at a 40 temperature of 50° C. After two hours a 0.30 molar The reactants and solvents listed below were charged solution of bis(chloromethyl) ether in cyclohexane was to a one-quart bottle which was then agitated at 30 C. added and the reactions were allowed to continue at the for 2 hours. At the end of this time, the solution was Same temperature for 15 more hours. Parallel runs to separated from the unreacted lithium wire by pressuring it which no bis(chloromethyl) ether was added were made into a clean bottle. A 2.0 milliliter sample was with 45 for control purposes. The polymerization time for these drawn by hypodermic syringe, added to distilled water, runs was 2 hours. All polymers were coagulated with and titrated to the phenolphthalein end point. Molarity isopropanol and vacuum dried after one weight percent as 1,2-dilithio-1,2-diphenylethane was calculated on the of 4,4'-thio-bis(6-tert-butyl-meta-cresol), based on the basis of total alkalinity and found to be 0.19. butadiene charged, was added to the wet crumb. The trans-Stilbene------. 14.4 grams (0.08 mole). 50 initiator level, amount of bis(chloromethyl) ether added, Lithium wire, low sodium----- 2.8 grams (0.4 g. atom). conversion, and results of inherent viscosity and gel de Diethyl ether, anhydrous------400 ml. terminations are shown in the following table: Tetrahydrofuran, anhydrous--- 40 ml. Time, hours------. 2. 55 1,2-dilithio-1,2-diphen-romethyl) Bis(chlo Temperature, C------30. ylethane, ether, Conver- Inherent Gel, Run immoles mnoles sion, viscosity 1 percent 2 The 1,2-dilithio-1,2-diphenylethane was employed as percent the initiator for the preparation of a series of butadiene styrene random copolymers which were high in styrene 1.1 ------00 , 83 0. 1. 1. 00 4.33 0 content. The runs were made using variable initiator 1.0 ------99 2.57 0. 1.0 ... O CO 4.42 0 levels. The polymerization recipe was as follows: 0.91------95 3.99 0 Butadiene, parts------25 0,9 0.9 00 5.6 O Styrene, parts------75 Cyclohexane, parts ------1,170 65 Same as in Example I. Tetrahydrofuran, parts?------2 Same as in Example I. 1,2-dilithio-1,2-diphenylethane, millimoles----- Variable All products weer gel free plastics but those which re " . Oried as described in Example. Sulted from the bis(chloromethyl) ether treatment had a 2 Distilled from lithium aluminum hydride. much higher inherent viscosity than those which were not Polymerization was effected at four initiator levels at 70 treated. These results indicate that a coupling reaction a temperature of 50° C. After two hours a 20-milliliter occurred. - sample was removed from each run in order to have poly Example VI mer representative of each recipe. Bis(chloromethyl) ether was then added as a 0.30 molar solution in cyclo A 15-70-15 styrene-butadiene-styrene rubbery block hexane to the remainder of each of the unquenched poly 75 copolymer was prepared using the 1,2-dilithio-1,2-diphen 3,078,254 S 16 ylethane initiator described in Example IV. The polym ing a few drops of concentrated sulfuric acid. Polysty erization recipe was as follows: rene precipitated and was recovered and dried. The Butadiene, parts------70 amount recovered in the B and C stages of the process is Styrene, parts------30 shown in the preceding table. Cyclohexane, parts"------17O 5 The 15-70-15 styrene-butadiene-styrene rubbery block 1,2-dilithio-1,2-diphenylethane, mmoles.------10 polymer which was coupled with bis(chloromethyl) ether Dried as described in Example I. had the following properties: The butadiene was charged and polymerization was ef Mooney value (ML-4 at 212 F.)------39 fected at 50° C. for three hours. Styrene was then added 300% modulus, p.S.i------and polymerization was continued for two hours at the 10 Green tensile, p.S.i.-- Same temperature. A sample was withdrawn at each Elongation, percent------920 Stage of the process, designated as A and B, and conver Sion, inherent viscosity, and gel were determined. Sam The rubbery block polymer (coupled product) was ples for these determinations were obtained by adding a compounded in two gum stock and two tread stock recipes Small quantity of isopropanol to the reaction mixtures lis as follows: and then evaporating the solvent at 57 C. for 24 hours in a vacuum oven. Some of the polymer from stage B Recipes (block polymer) was subjected to oxidative degradation and the percent polystyrene was obtained as well as the 1 (gun) 2 3 (gun) 4 inherent viscosity of the recovered product. A 0.30 molar 20 Polyner------100 10) 100 100 solution of bis(chloromethyl) ether was added to the re Carbon black (Philblack 0) ------50 ------5. maining unquenched polymer solution and the reaction Zinc oxide------3 3 3. 3 Stearic acid 2 2 2 2 was allowed to continue for 16 more hours at 50 C. Resin 731 b--- 3 3 3 3. The product was coagulated with isopropanol and vacu Flexamine Sulfur------8 1.8 2.0 2.0 um dried. A rubbery polymer was obtained. A portion 25 Santocured. .2 l? ------of the resulting material was subjected to oxidative degra Methyl Tuads------0.9 O.9 dation. The percent polystyrene was determined and also Captax.------. 0.4 O. : the inherent viscosity of the recovered product. Results a High abrasion furnace black. are shown in the following table: 30 b Disproportionated palerosin stable to heat and light, o Physical mixture containing 65 percent of a complex diarylanine Polysty Inherent it. reaction product and 35 percent of N,N'-diphenyl-p-phenylene Conver. Inher- Gel, Refrac- rene by viscosity lie Stage of sion, ML-4 ent vis-per- tive degrada- of recov dN-cyclohexyl-2-benzothiazylsulfenanide. process percent 212°F. cosity 1 cent 2 index Stive oxi- ered Tetramethylthiuran disulfide. dation, product 2-mercaptobenzothiazole. -|--|--|T.ece, 35 The stocks were cured 45 minutes at 307 F. and 100 ------0.29 0 1.5138 ------physical properties determined. Recipes 3 and 4 were 100 ------0.27 O 15369 4. 0.02 intended to give tight cures. Results were as follows: 9.5 38.5 O O 5363 22.8 0.07 Sample 300% Teasie, Elonga- Re- AT, 2 S.ame as inin Example I. 40 from modulus, p.S.i. tion, V10 silience, o F.12 8 Same as in Example III. recipe p.s.i. percent percent The block polymer, both before and after treatment with bis(chloromethyl) ether, was subjected to a degrada 1------240 900 O 0.32. 55.3 0.2 2------1,960 2,920 450 0.355 44.6 79.7 tive oxidation procedure which destroyed the polymer 3------40 530 30 0.392 5S.9 3.4 molecules that contained unsaturation (polybutadiene). 4------2,810 280 0.44 5.2 S. This oxidation method is based upon the principle that 45 The 300% modulus, tensile strength and elongation of the rubber polymer molecules containing ethylenic bonds, when dis samples were determined by a modification of ASTM D12-5iT. Test specimens were died out of slabs 20 mills thick using Type D die. These Solved in p-dichlorobenzene and toluene, can be broken specimens neasured 4' long and 0.25' wide in the flat test section. into fragments by reaction with tert-butyl hydroperoxide Stress-strain properties were obtained at 73-42 C. The cross-lead speed in these tests was 20' per minute. catalyzed with osmium tetroxide. Saturated polyner 10 The V determination was made by cutting samples of the cured molecules or molecular fragments such as polystyrene or 50 E}olyner wicighing approximately 1.5 grains fron regular tensile slabs, the polystyrene units in block polymers containing no weighing their or an analytical balance, and allowing them to swell in n-heptane for 6 days at 30°C. The swollen specimens were blotted with ethylenic bonds remain unattacked. The small fragments filter paper and transferred quickly to tared weighing bottles. The volume of imbibed solvent was obtained by dividing the difference (low molecular weight aldehydes) and the low molecu between the weight of the Swollen sample and the weight of the dry, lar weight polystyrene fragments from the copolymer extracted Sample (dried 16 hours at 70° C. in vacuo) by the density of the Solvent. Next the dry samples were weighed in methanol and their block are soluble in ethanol whereas the unattacked high 55 volume calculated. From this volume was subtracted the volume of molecular weight polystyrene from the styrene homopoly fillers (calculated from the recipe and original Sainpie weight) giving the volume of polymer. The latter was used to calculate the volume raction mer block is insoluble in ethanol. It is thus possible to of polymer in the swollen stock (W). This method is described in Rub effect a separation of the high molecular weight polysty ber World, 135, No. 1, 67-73 (1956). ii Dcternained using a Yerzley oscillograph. The method is ASTM rene which constitutes the homopolymer block of the D945-55 except for the size of the specimen. It is a right circular cylinder block polymer. 60 0.7' in diameter and ' high. 12 Determined using a Goodrich flexometer. The results are expressed Approximately 0.5 gram of the polymer to be subjected in degrees F. The method is ASTM D623-52T, Method A; 143 p.s.i. to the oxidation procedure was cut into small pieces, load, 0.175-inch stroke, 100 F. oven. AT equals rise in temperature weighed to within one milligram, and charged to a 125 above 100°F. Owen in 5 Iminutes. milliliter fiask. Forty to 50 grams of p-dichlorobenzene Two 15-70-15 styrene-butadiene-styrene block poly was then charged to the flask and the contents were heated 65 mers having Mooney values of 27 and 56, respectively, to 130° C. This temperature was maintained until the which had not been treated with bis(chloromethyl) ether, polymer was dissolved. The solution was then cooled had the following properties: to 80 to 90° C. after which 8.4 ml. of a 71.3 weight per cent aqueous solution of tert-butyl hydroperoxide was 2 added. One milliliter of 0.003 molar osmium tetroxide 70 in toluene was then added to the reaction mixture and Mooney value (ML-4 at 212 F.).------27 56 300%. Modulus, p.S.i.------350 430 the resulting solution was heated to between 110 and 115 Tensile, p.S.i.------w 60 8:0 C. for 10 minutes. The solution was cooled to between Elongation, percent.-- G5 730 50 and 60° C. 20 m. of toluene was added, and the mix Same as in Example III. ture was poured slowly into 250 ml. of ethanol contain- 75 Sane as in Example WI. 3,078,254 17 3. These rubbery polymers were compounded in the fore means of hypodermic syringes. The amount of func going tread stock recipes designated as 2 and 4. The tional group added was either one or two equivalents per stocks were cured 45 minutes at 307 F. and physical lithium atom in the initiator. Runs were also made properties determined. Results were as follows: using 1,5-dichloropentane and 1,5-dibromopentane as ad ditives. The temperature was maintained at 50° C. for Com- 300% Elonga- Re- AT, one hour after which the polymers were coagulated with Polymer pounding modulus, Tensile, tion, silience, F.12 isopropanol, dried in a forced-air oven at 125 F., and recipe p.s.ii.9 p.s.i. percent percent 11 then in a vacuum oven. One series of runs was made for control purposes. At the end of the polymerization, a 27 ML-4 2 2,510 2,810 365 46.6 197.0 56 ML-4 2 2,900 2,960 30 49.0 89.6 toluene solution of phenyl-beta-naphthylamine was added 27 M-4. 4------2,700 160 52.5 85.3 to the controls which were then coagulated by addition 56 ML-4-- 4------2,70 80 56.6 86.0 of isopropanol. The polymers were dried in a forced air oven at 125 F. and finally in a vacuum oven. Results 111 Same as shown earlier in this example. of inherent viscosity and molecular weight determinations These data show that the coupled products had no sig- 15 were as follows:

Initiator level, millimoles Equiv Treating agent alents 5 10

M.W.13 I.V. M.W. None------1,2-bis (bronomethyl) benzene.

33,80?) 1,4-bis (chloromethyl) benzene--- : --- 0.7 34,100 Bis (chloromethyl) ether.------. 1. 87,100 0.82 43,000 1,5-dichloropentane------0.53 22,000 l,5-dibromopentane------0.56 23,600

11. SameThe molecularas in Example weights I. were calculated by means of the equation insKM using the value of K for sodium-polymerized polybutadiene as reported by Scott, Carter, and Magat, J. Am. Chem. Soc. 71,220 (1949).

nificant difference in tensile strength from the polymers Addition of an equivalent of 1,5-dichloro- or 1,5-di which had not been treated with bis(chloromethyl) ether bromopentane did not result in coupling, as can be seen but they had much greater elongation and much better 40 from the data. These compounds are outside the scope heat build-up properties than the untreated rubbers. of active halogen-containing compounds of the invention. Example VII An n-pentane solution of n-butyllithium was prepared Example VIII by reacting lithium wire and n-butyl chloride in n-pentane. 45 Molarity of the initiator was determined by titration for 1,4-dilithiobutane was prepared in accordance with the total alkalinity. following recipe: Butadiene was polymerized in the presence of n-butyl Diethyl ether, ml------350 lithium in accordance with the following recipe: 1,4-dichlorobutane, moles------0.10 50 Lithium metal dispersion, moles------0.50 Butadiene, parts by weight------100 Cyclohexane, parts by Weight------390 n-Butyllithium, millimoles------Variable The diethyl ether was dried over sodium wire and dis Temperature, C------50 55 tilled from lithium aluminum hydride. The 1,4-dichloro Time, hours------4 butane was purified by washing first with concentrated sulfuric acid and then with water followed by drying over Polymerization was effected in 7-ounce bottles and calcium sulfate and distilling. quantitative conversion was obtained. The butadiene em A one liter Morton flask was provided with a high ployed was special purity grade which was distilled and 60 speed stirrer, a gas inlet, a condenser, and a dropping the gaseous material was dried by passing it through funnel. The apparatus was first swept with dry, oxygen ethylene glycol before it was condensed. Pure grade free nitrogen for 15 minutes after which 200 milliliters cyclohexane was dried over silica and alumina and then of diethyl ether was introduced. While passage of ni bubbled in gallon lots with prepurified nitrogen for 30 trogen through the flask was continued, the lithium dis minutes at the rate of 3 liters per minute. Samples for persion was added. An ether solution of 1,4-dichloro polymerization were prepared by charging dry cyclohex butane was introduced slowly while the temperature was ane to the bottles first and then passing prepurified nitro maintained between -10 and -30° C. After the addi gen through the solvent for 5 minutes at the rate of 3 tion was completed, the mixture was stirred for two hours liters per minute. The bottles were capped and butadiene and the temperature was allowed to rise slowly to room and n-butyllithium were added by means of a hypodermic 70 Syringe. temperature. The excess lithium metal and lithium salt At the end of the polymerization, cyclohexane solu were separated from the solution by centrifuging. Titra tions of bis(chloromethyl) ether, 1,2-bis(bronomethyl)- tion for total alkalinity indicated at 63 percent yield, cal benzene, and 1,4-bis(chloromethyl)benzene were added culated as dilithiobutane. to one set of the unterminated polymer solutions by 75 1,4-dilithiobutane was used as the initiator for the 3,078,254 polymerization of butadiene in accordance with the fol lution of bis(chloromethyl) ether. Results were as foll lowing recipe: lows:

Butadiene, parts------100 Initiator Bis(chloro- Inherent Approximate Cyclohexane, parts------390 Run No level, methyl) viscosity molecular 1,4-dilithiobutane, millinoles------Variable innoles ether, Innoles weight 13 Temperature, C------50 1A.------5 None 0.68 33,000 Time, hours------1B------5 5 3.34 40,000 2A.------O None 0.28 7,600 2B------10 O 1,95 180,000 The polymerization procedure was the same as that de O scribed in Example VII. Treatment with bis(chloro : Same as in Example I. methyl) ether was also the same as in the preceding 13 Same as in Example VII. example. Results were as follows: All products were gel free. The marked increase in molecular weight upon treatment with bis(chloromethyl) 5 ether indicated coupling. Initiator level Bis (chloro methyl) Inherent Example X Rin No ether viscosity Millinoles Millieduiv- millieguiv A lithium-naphthalene adduct was prepared as follows: alents alents Naphthalene, moles------0.05

2O 3 6 None 1.9 Lithium wire, low Sodium, moles------0.20 3. 6 3 7.27 3 6 6 7.25 Tetrahydrofuran, ml------170 3 2 6, 67 5 O None 0.73 Temperature, C------25 5 10 5 6,09 Time, hours------0.75 5 O O 5.43 5 O 20 4.38 25 Yield, percent (as dilithio adduct).------100 5 30 None 0.36 15 30 15 0.67 The naphthalene was recrystallized from alcohol. The 15 30 30 ... 8 tetrahydrofuran was refluxed and distilled from lithium 5 30 60 E. 63 aluminum hydride. A 500-ml. Morton flask provided with a high speed Same as in Example I. 30 stirrer, gas inlet, and condenser was used for the reaction. The apparatus was first swept with prepurified nitrogen for All products were gel free. A spectacular increase in 15 minutes after which the tetrahydrofuran was introduced. inherent viscosity was noted after treatment with bis Naphthalene and lithium wire were introduced while pas (chloromethyl) ether. The coupling reaction proceeded sage of nitrogen through the flask was continued. The at a very rapid rate. 35 stirrer was started. The reaction was very rapid and exothermic, and after 45 minutes the mixture was siphoned Example IX into a 7-ounce bottle, the excess lithium wire being left 1,2-dilithio-1,2-diphenylethane was prepared in accord in the flask. ance with the following recipe: The lithium-naphthalene adduct was used as the initiator 40 for the polymerization of butadiene. The resulting un Trans-Stilbene, moles------0.10 quenched polymer solution was treated with bis(chloro Lithium wire, gram atoms------0.30 methyl) ether. The procedures for both polymerization Diethyl ether, ml------600 and coupling reactions were as described in Example VII. The polymerization recipe was as follows: Temperature ------Reflux 45 Time, hours------3.5 Butadiene, parts------100 A one-liter creased flask provided with a high speed Cyclohexane, parts------780 stirrer, gas inlet, and condenser was swept with prepuri Lithium-naphthalene adduct, millimoles.------Variable fied nitrogen for 15 minutes. Anhydrous diethyl ether Temperature, C------50 was introduced followed by lithium wire while passage 50 Time, hours------of nitrogen through the flask was continued. Trans-Stil Conversion, percent------100 bene was introduced, the stirrer was started, and tem Results of treatment with bis(chloromethyl) ether were perature was regulated at slow refluxing of the ether. as follows: After 3.5 hours the reaction mixture was siphoned into 55 12-ounce bottles, the excess of lithium wire being left in Initiator Bis(chloro- Inherent Approximate the flask. The yield, based on alkalinity, was 44 percent. Run No level, Inethy) viscosity molecular It was determined by hydrolyzing 2 ml. of the solution Innoles ether, minoles weight 13 and titrating it with 0.1 NHC using phenolphthalein as 3 None 3.11 69,000 the indicator. 3 3 2.43 250,000 The 1,2-dilithio-1,2-diphenylethane was employed as 5 None 0.79 4,000 5 1.49 10,000 the initiator for the polymerization of butadiene in ac O None 0.50 19,000 cordance with the following recipe: 0 O 0.83 44,000 Butadiene, parts------100 Same as in Example I. Cyclohexane, parts------780 65 3 Same as in Example VII, 1,2-dilithio-1,2-diphenylethane, millimoles----- Variable Having thus described the invention by providing Specific examples thereof it is to be understood that no Temperature, C------50 undue limitations or restrictions are to be drawn by Time, hours------reason thereof and that many variations and modifications Conversion, percent------Quantitative 70 are within the scope of the invention. We claim: Cyclohexane was charged first, followed by butadiene 1. A process for the preparation of polymer of increased and then the initiator. The procedure was the same as molecular Weight which comprises reacting at a tempera that described in Example VII, including treatment of ture in the range of -100 to --150° C. a terminally re the unquenched polymer solution with a cyclohexane so- s active polymer having the formula PY, wherein P com 3,078,254 2. 22 prises a polymer of polymerizable vinylidene compounds, at least two active halogen atoms and being otherwise Y is a terminally positioned alkalimetal and n is an integer inert to said alkali metal, each halogen atom being at of 1 to 4, with an organic reactant material having up tached to a carbon atom which is alpha to an activating to 20 carbon atoms and containing at least two active group selected from a group consisting of ether linkage, halogen atoms and being otherwise inert to said alkali carbonyl, and metal, each halogen atom being attached to a carbon atom which is alpha to an activating group selected from -CsC the group consisting of ether linkage, carbonyl, and and thereafter reacting molecules of the polymer product by heating at a temperature in the range of 100 to 500 F. O 10. The process of claim 9 in which heating of the 2. A process for the preparation of polymer of increased molecules of polymer product is carried out in the presence molecular weight which comprises reacting at a tempera of a conventional curing system. ture in the range of -100 to -150° C. a terminally re 11. The process of claim 9 in which the polymer is a active polymer having the formula PY, wherein P con homopolymer of butadiene and the organic reactant is prises a polymer of polymerizable vinylidene compounds, 5 bis(chloromethyl) ether. Y is a terminally positioned alkali metal and n is an integer 12. The process of claim 9 in which the polymer is of 1 to 4, with from 0.5 to 5 equivalents per equivalent of a homopolymer of styrene and the organic reactant is alkali metal in the polymer of an organic reactant ma bis(chloromethyl) ether. terial having up to 20 carbon atoms and containing at least 13. The process of claim 9 in which the polymer is a two active halogen atoms and being otherwise inert to 20 block copolymer of butadiene and styrene and the organic said metal, each halogen atom being attached to a carbon reactant is bis(chloromethyl) ether. atom which is alpha to an activating group selected from 14. The process of claim 9 in which the polymer is a a group consisting of ether linkage, carbonyl, and homopolymer of butadiene and the organic reactant is 1,2- bis(bromomethyl)benzene. --&- 15. The process of claim 9 in which the polymer is a 3. The process of claim 2 in which the polymer is a homopolymer of butadiene and the organic reactant is 1,4- homopolymer of butadiene and the organic reactant is bis(chloromethyl)benzene. bis(chloromethyl) ether. 16. The composition prepared in accordance with the 4. The process of claim 2 in which the polymer is a process of claim 1. homopolymer of styrene and the organic reactant is 30 17. The composition prepared in accordance with the bis(chloromethyl) ether. process of claim 3. 5. The process of claim 2 in which the polymer is a 18. The composition prepared in accordance with the copolymer of butadiene and styrene and the organic re process of claim 4. actant is bis(chloromethyl) ether. 19. The composition prepared in accordance with the 6. The process of claim 2 in which the polymer is a 35 process of claim 5. block copolymer of butadiene and styrene and the or 20. The composition prepared in accordance with the ganic reactant is bis(chloromethyl) ether. process of claim 9. 7. The process of claim 2 in which the polymer is a homopolymer of butadiene and the organic reactant is 1,2- References Cited in the file of this patent bis(bromomethyl)benzene. 40 8. The process of claim 2 in which the polymer is a UNITED STATES PATENTS homopolymer of butadiene and the organic reactant is 2,666,042 Nozaki------Jan. 12, 1954 1,4-bis(chloromethyl)benzene. 2,913,444 Diem et al. ------Nov. 17, 1959 9. A process for the preparation of polymer of increased FOREIGN PATENTS molecular weight which comprises reacting at a tempera 5 ture in the range of -100 to --150° C. a terminally re 339,243 Great Britain ------Dec. 1, 1930 active polymer having the formula PY, wherein P com OTHER REFERENCES prises a polymer of polymerizable vinylidene compounds, Y is a terminally positioned alkali metal and n is an in Heany et al.: "J. Chemical Society,' 1956, volume 1, teger of 1 to 4, with from 0.5 to 5 equivalents per equiva 50 page 4692. lent of alkali metal in the polymer of an organic reactant Whitby: "Synthetic Rubber,” John Wiley and Sons, material having up to 20 carbon atoms and containing New York, 1954, page 396.