Abstract: A new class of macromolecular monomers (hereinafter called "macromonomers") comprises the polymerized product of at least one of an ethenylarene and a conjugated diene monomer, the product having a terminal omega-alkenyl group of at least four carbon atoms. The novel macromonomer can be copolymerized with ethylene and alpha-olefin monomers to form graft copolymers having pendant side-chains. The graft copolymers are useful as coating and molding compositions. The macromonomers can be useful as coatings on chromatographic supports for analytical and preparative separation of chemical mixtures.

Abstract: A shape memory polymer resin, consisting essentially of a block copolymer having an A-B-A block structure in the polymer chain, and having a weight average molecular weight within the range of 10,000 to 1,000,000, wherein(a) block A is a polymer block comprising a homopolymer or a copolymer of a vinyl aromatic compound and/or a hydrogenated product thereof;(b) block B is a polymer block comprising a homopolymer or a copolymer of butadiene and/or a hydrogenated product thereof, the content of butadiene and/or the hydrogenated product thereof in block B being at least 80% by weight, and 80 to 91% of the linkages of the butadiene and/or the hydrogenated product thereof being 1,4-linkages;(c) at least 80% by weight of the conjugated diene in the block copolymer being hydrogenated; and(d) the block copolymer comprises 5 to 50% by weight of said block A; and a shape memory resin composition and a shape memorizing molded product thereof.

Abstract: There is disclosed a linear block copolymer comprising at least one triblock I-B-I, wherein I is a block of a polymerized conjugated diene of at least 5 carbon atoms, such as isoprene, and B is a block of a polymer of a conjugated diene, different from that of formula (1), of at least 4 carbon atoms, such as 1,3-butadiene. The B block is selectively hydrogenated, while each of the I blocks retains a sufficient amount of its original unsaturation to vulcanize the copolymer. There is also disclosed an alternative linear block copolymer containing at least one triblock of the first polymer block made from an aryl-substituted olefin, such as sytrene, and the conjugated diene used to polymerize the block I, the second middle polymer block of the diene used to polymerize the block B, and the third polymer block which is the same as the first polymer block.

Abstract: An organic compound of an alkali metal, of the formula I ##STR1## which is obtained by reaction of an appropriate diarylethylene of the formula II with an alkali metal (M), especially lithium, ##STR2## where Ar.sup.1 and Ar.sup.2 are identical or different aryl or hetaryl radicals which have one or more rings which are either separate or fused, and where R is at least one substituent different from hydrogen and which is chemically inert to the alkali metal or its alkyl, with the proviso that the total of the carbon atoms in all the R is at least 3, and m and n are each an integer up to 4, is used for the preparation of polymers whose monomers are amenable to anionic polymerization.

Abstract: Linear copolymers with four alternating blocks, represented by the following formula:B.sub.1 -T-A.sub.1 -B.sub.2 -A.sub.2where: A.sub.1 and A.sub.2 are polyvinylaromatic blocks, B.sub.1 and B.sub.2 are blocks consisting of ethylene-butene-1 or ethylene-propylene copolymers, and T is a statistical terpolymer segment formed from ethylene-propylene-vinylarene or ethylene-butene-1-vinylarene monomer units.The copolymers are characterized by a weight-average molecular weight of between 20,000 and 300,000 and a total content of vinylaromatic units of between 10 and 60% by weight. The ratio of the weight-average molecular weight of block A.sub.1 to that of block A.sub.2 is a number between 0.25 and 2.0, and the ratio of the weight-average molecular weight of block B.sub.1 to that of block B.sub.2 is a number between 0.05 and 0.5.

Abstract: A crystalline block copolymer containing at least a triblock or at least a radial structure and a process for producing the same, wherein at least one block comprising a vinyl aromatic compound having a glass transition temperature (Tg) of not lower than 50.degree. C., at least one block comprising a conjugated diene polymer having a 1,4-trans linkage content, a Tg not higher than 10.degree. C. and crystallinity at 25.degree. C. and in which the crystalline block copolymer optionally which contains the radial structure further comprises a coupling agent. The polymer or the composition containing the same can be utilized for fixing materials of affected portions for medical purposes, protector materials for various sports, films, laminates, toys, artificial flowers, heat-sensitive sensors, coupling devices, insulating materials, framework materials, etc.

Abstract: Functionalized polymers obtained from metallated crystalline copolymers of one or more alpha-olefins with minor proportions of a diene by reaction with monomers polymerizable of anionic methods or with compounds that react with the metallated copolymer.The metallated copolymer is obtained by reaction of the olefin copolymer with organometallic compounds of lithium, in suspension in an inert solvent.The lithiation stage and the subsequent polymer modification reaction take place in inert hydrocarbon suspension at a temperature below that of the swelling point of the starting copolymer.

Abstract: An unsaturated, elastomeric, asymmetrically coupled block copolymer of the formula:(A--B).sub.n --X--(B).sub.m,wherein block A is a block of polybutadiene having an 8 to 60% content of uniformly distributed vinyl groups and block B is a homopolymer of isoprene or a copolymer of at leat 10% isoprene units with 0 to 60% butadiene units and up to 45% styrene units and X is a radical of a coupling agent, and (m-n).gtoreq.0 while (m+n) ranges from 3 to 25.

Abstract: A diene block polymer contains (A) a resinous polybutadiene block having a glass transition temperature of -80.degree. C. or less, a crystalline melting point of 30.degree. to 130.degree. C., 80% to 93% of trans units, 5 to 15% of cis units, and 1 to 10% of vinyl units, a molecular weight of 10,000 to 200,000, and a molecular weight distribution Mw/Mn of 1.2 to 4 and (B) a conjugated diene rubbery block having a glass transition temperature of -20.degree. C. or less and either not having a crystalline melting point or having a crystalline melting point of 0.degree. C. or less, wherein the ratio of blocks (A) to blocks (B) is 2 to 80:98 to 20 (ratio by weight), the molecular weight is 20,000 to 500,000, and the molecular weight distribution Mw/Mn is 1.1 to 5 and a polymer composition containing the same.

Abstract: A method for preparing tapered block copolymers in a polymerization process by charging an initiator and monomers sequentially with one or more charges of first one of the monomers, then with a mixture of the two monomers, and then with one or more charges of the second monomer alternating with one or more charges of the first monomer with subsequent coupling, to produce a polymodal tapered block copolymer. Suitable monomers include conjugated dienes and monovinylaromatic compounds. The copolymers are suitable for use in injection and blow molding equipment; the copolymers are particularly useful for shrink films, containers, tubes, fibers and other packaging applications.

Abstract: A terminal-modified block copolymer having the remainder of an amino group or imido group-containing a terminal-treating agent bonded to the polymer terminal which is obtained by treating the active terminal of a block copolymer comprising conjugated dienes and vinylaromatic hydrocarbon compounds, which is obtained by using as the polymerization initiator at least one member selected from alkali metals or organoalkali metals and has a vinylaromatic hydrocarbon content of 5 to 95% by weight and a number average molecular weight of 5,000 to 1,000,000 with at least one terminal-treating agent selected from imide compounds, cyanamide compounds, aziridinyl compounds, amide compounds, or tertiary amino group-containing compounds other than the compounds.

Abstract: A new class of macromolecular monomers (hereinafter called "macromonomers") comprises the polymerized product of at least one of an ethenylarene and a conjugated diene monomer, the product having a terminal omega-alkenyl group of at least four carbon atomes. The novel macromonomer can be copolymerized with ethylene and alpha-olefin monomers to form graft copolymers having pendant side-chains. The graft copolymers are useful as coating and molding compositions. The macromonomers can be useful as coatings on chromatographic supports for analytical and preparative separation of chemical mixtures.

Abstract: A block copolymer composition comprising40-85% by weight of a block copolymer A.sub.1 -B.sub.1 from an aromatic vinyl compound and a conjugated diene, respectively, A.sub.1 being <20% by weight of (A.sub.1 +B.sub.1), A.sub.1 and B.sub.1 having a molecular weight >12,000 and >150,000, respectively, and15-60% by weight of a block copolymer A.sub.2 -B.sub.2 -A.sub.3 from an aromatic vinyl compound, a conjugated diene and aromatic vinyl compound, respectively, A.sub.2 +A.sub.3 being >20% by weight of A.sub.2 +B.sub.2 +A.sub.3, A.sub.2 and A.sub.3 having a molecular weight >12,000 and(molecular weight of B.sub.2).ltoreq.(molecular weight of B.sub.1)/1.5. an adhesive composition comprising100 parts by weight (pbw) of said block copolymer composition, 20-300 pbw of a tackifying resin, and0-200 pbw of a softener, anda process for the preparation of said adhesive composition by mixing the components in question.

Abstract: An unsaturated elastomeric AB block copolymer comprising 20-75 wt. % 1,3-butadiene monomer units; 5-50 wt. % isoprene monomer units; and 3-30% wt. % styrene monomer units; wherein said block copolymer contains less than 3 wt. % styrene blocks, each of said block A and block B contain all three of said monomer units, said copolymer comprises 30-90 wt. % of block A and 70-10 wt. % of block B, and wherein the average vinyl and isopropenyl content of block B are each at least 30% higher than those of block A; and a method for preparing the unsaturated AB block copolymer.

Abstract: A copolymer of an .alpha.-olefin with an aromatic diolefin such as divinylbenzene produced by means of Ziegler-Natta polymerization and having a vinylphenyl moiety is subjected to polymerization with an ethylenically unsaturated monomer by means of anion polymerization or free radical polymerization, whereby a graft-modified .alpha.-olefin copolymer is obtained.

Abstract: Disclosed is a polymer alloy consisting essentially of a composition of a polyphenylene ether, a crystalline propylene resin, and an alkenyl aromatic monomer modified propylene-dialkenylbenzene compound copolymer. The composition excels in heat resistance and resistance to oils.

Abstract: Butadiene is polymerized alone or with a monomer such as styrene in a dispersion in propane, butane or its mixtures with minor amounts of other C.sub.4 -C.sub.6 alkanes, e.g., n-pentane and a dispersant which is preferably a styrene/hydrogenated isoprene block copolymer to achieve stable dispersions at higher solids and butadiene levels possible with similar alkane dispersants.

Abstract: Narrow molecular weight telechelic and/or block copolymers are prepared by anionic polymerization using an initiator composition comprising a multifunctional lithium initiator in combination with an organic diamine or triamine and optionally a metal alkoxide.

Abstract: Elastomeric polymers comprising at least one alkali metal atom are modified by incorporating at least one group capable of sterically hindering coupling reactions which frequently occur when functional groups are subsequently incorporated into such polymers. In general, the group capable of sterically hindering coupling reactions may be incorporated by reacting the elastomeric polymer comprising at least one alkali metal atom with a compound containing a group capable of reacting with the elastomeric polymer at one end and at least one pendant group larger than hydrogen at the other. Groups that will react with elastomeric polymers comprising at least one alkali-metal atom are of course, well known, in the art, and include groups containing sulfur, oxygen, nitrogen and the like and ethylenically and acetylenically unsaturated groups. Compounds containing terminal ethylenically unsaturated groups are particularly useful in preparing the modified elastomeric polymers of this invention.

Abstract: A process for neutralizing the terminated remnant of an alkali metal anionic polymerization initiator comprising contacting the remnant with an organic acid halide.

Abstract: Bimodal star-block copolymers are disclosed containing from 60 to 90% by weight of an aromatic vinyl monomer and from 40 to 10% by weight of a conjugated diene, said copolymers having the general formula:(S--S.sub.1 --B/S.sub.2 --B.sub.1).sub.m --X--(B.sub.1 --S.sub.2 /B--S.sub.1).sub.nwherein X is a polyfunctional radical, m and n are integers (being m.ltoreq.n) the sum of which is between 3 and 20 and equal to the functionality degree of the radical X, S and S.sub.1 are polymer blocks of an aromatic vinyl monomer, B.sub.1 is an elastomeric copolymer of conjugated dienic units, containing up to 20% of all the dienic units of the copolymer, and B/S.sub.2 and S.sub.2 /B are blocks of copolymers of aromatic vinyl monomer and conjugated diene of the random and/or tapered type.

Abstract: Polyisoprenes having a high content of 1,2- and 3,4-structural units, a process for their preparation, and their use.The previous processes for the preparation of polyisoprene having a high content of 1,2- and 3,4-structural units were still unsatisfactory in terms of the cocatalyst employed.The use of ethylene glycol dialkyl ethers of the formulaR.sub.1 --O--CH.sub.2 --CH.sub.2 --O--R.sub.2in which R.sub.1 and R.sub.2 are alkyl groups having different numbers of C atoms, from the group consisting of methyl, ethyl, n- and isopropyl and n-, iso-, sec.- and tert.-butyl, has, in particular, the advantage that the "living polymers" formed during the anionic polymerization are not damaged.The production of tires and damping elements using these polyisoprenes.

Abstract: A thermosetting resin composition comprising a special poly(p-hydroxystyrene) derivative resin and a radical polymerization initiator, and if necessary an epoxy modified polybutadiene, can provide prepregs and laminates having a low dielectric constant, a shorter signalling delay time, good heat resistance and flame retardancy and thus being suitable for producing multilayer printed circuit boards.

Abstract: In curing dental resins, polymerizable compounds having at least one ethylenically unsaturated double bond, such as mono- or poly-functional acrylates or methacrylates are polymerized in the presence of N-cyclohexy-5-ethylpyrimidinetrione, a specific organometallic compound typically including acetylacetone copper or lithium acetate, and an organohalogen compound. The amounts of the ethylpyrimidinetrione, organometallic and organohalogen compounds used are respectively 0.1 to 10 parts by weight, 0.001 to 0.2 parts by weight and 0.1 to 5 parts by weight with respect to the polymerization compounds.

Abstract: A linear copolymer constituted by four alternating blocks:B1-A1-B2-A2wherein:B1 and B2 are polydienic blocks, and preferably polybutadiene blocks, andA1 and A2 are polyvinylaromatic, and preferably polystyrene blocks;which polymer has a weight average molecular weight of from 30,000 to 250,000, and a global content of monomer dienic units of from 40 to 80% by weight, wherein the weight average molecular weight of B1 block is comprised within the range of from 0.1 to 0.5 times the weight average molecular weight of B2 block, and the weight average molecular weight of A1 block is comprised within the range of from 0.25 to 2.0 times the weight average molecular weight of A2 block, and which contains between B1 and A1 blocks a copolymeric moiety formed by randomly linked monomer dienic and vinylaromatic units; is endowed with a desired balance of mechanical characteristics, rheologic characterisatics and characteristics of thermooxidative resistance.The process to prepare such a block copolymer is disclosed.

Abstract: High molecular weight linear block copolymers containing 5 or more alternating blocks of (A) polymerized styrene or alkyl substituted styrene units, and (B) polymerized conjugated diene units, terminated by (A) units, are prepared by anionic dispersion polymerization to give clear polymers having excellent physical properties.

Abstract: A graft copolymer having a plurality of polymer side chains is disclosed. The starting backbone polymer is a homopolymer or copolymer of a styrene derivative having a pendant vinylidene group on the benzene ring. The graft copolymer may be produced by metallizing said backbone polymer with an alkali metal and then polymerizing an ethylenically unsaturated monomer in the presence of the metallized polymer as an anionic polymerization initiator.

Abstract: A star-shaped polymer useful as a polymeric VI improver comprising at least one arm which is a block copolymer containing a conjugated diolefin block and a monoalkenyl aromatic hydrocarbon block and a plurality of arms which are either a homopolymer of a conjugated diolefin or a copolymer of tow or more conjugated diolefin or a copolymer of two or more conjugated diolefins. Oil compositions comprising star-shaped VI improvers of this type exhibit relatively low HTHSR viscosities, and hence, improved fuel efficiencies when used in automotive applications. Oil compositions comprising star-shaped VI improvers of this type also exhibit improved low temperature pumpability.

Abstract: Macromonomer prepared by contacting and reacting a polymer (oligomer) having at least three monomer repeat units and at least one silyl ether group, in the presence of an anion catalyst, with a terminally unsaturated acyl fluoride or sulfonyl fluoride.

Abstract: A process for producing a thermoplastic elastomer comprising a block copolymer of the A-B-A' type, wherein A is a monovinyl aromatic hydrocarbon polymer block, B is a conjugated diolefin polymer block, and A' is either the same as A or a polymer block derived from a dialkenyl aromatic hydrocarbon or a dihalogenated hydrocarbon, which process comprises polymerizing a monovinyl aromatic hydrocarbon in a polymerization medium in the presence of an organomonolithium compound as a polymerization initiator, adding a conjugated diolefin to perform block copolymerization, and further adding a monovinyl aromatic hydrocarbon to perform polymerization or in the alternative, adding a dialkenyl aromatic hydrocarbon or a dihalogenated hydrocarbon to perform coupling, wherein the monomer components are used in such amounts that the weight ratio of (A+A') to B ranges from 10/90 to 65/35, and a chained aliphatic hydrocarbon solvent containing from 0.0001 to 0.

Abstract: Block polymers of vinylaromatic compounds and conjugated dienes which possess acidic terminal groups, are present in the form of lithium salts and form an aluminum complex. A process for the preparation of such complexes and the use of these block polymer complexes as molding materials and for modifying thermoplastic materials.

Abstract: ABC block copolymers on the basis of butadiene, isoprene and optionally styrene, are provided by a polymerization process wherein the resultant block copolymer comprises:about 40 to 75 wt % of a block A based on butadiene (uniformly distributed vinyl group content less than about 15 wt %),up to about 25 wt % of a block B based on butadiene and isoprene (vinyl content less than about 15 wt %) or based on butadiene (vinyl content more than about 75 wt %)about 20 to 55 wt % of a block C based on butadiene and isoprene (vinyl content more than about 75 wt %). The ABC block copolymers are useful for the production of tire treads.

Abstract: A rubber composition suitable for tire treads having well-balanced excellent wet skid characteristic, ice skid characteristic and rolling characteristic, and an excellent processability, which comprises a rubber component containing at least 20% by weight of a block copolymer consisting essentially of a block A and a block B, obtained by conducting polymerization of an aromatic vinyl compound and a conjugated diene compound in a hydrocarbon solvent in the presence of an organolithium initiator and modifying with a coupling agent, and satisfying the following conditions (A) to (E);(A) the block A having a content of an aromatic vinyl compound of at most 5% by weight and a content of 1,2-bonds in the conjugated diene component of at least 10% by weight,(B) the block B having a content of an aromatic vinyl compound of 25 to 50% by weight and a content of 1,2-bonds in the conjugated diene component of at least 10% by weight,(C) a content of the block A in the block copolymer being from 20 to 80% by weight,(D) a c

Abstract: A process is provided for metallating ethylene polymers which have polymerized therein a minor amount of nonconjugated diene. Metallation is accomplished with a blend of three metallating reagents: (a) an alkyllithium compound; (b) a potassium alkoxide; and (c) a chelating tertiary diamine. The metallated polymers so prepared may be reacted with one or more anionically polymerizable monomers to form graft polymers or with a reagent such as carbon dioxide to form a functionalized polymer. When the anionically polymerizable monomer has two or more polymerizable sites, the metallated polymer is reacted with a modifying compound such as alpha-methylstyrene before it is reacted with the monomer(s). Certain of the graft polymers behave as thermoplastic elastomers whereas others are thermoplastic. The blend of metallating reagents may be used with any polymer having partial or complete unsaturation.

Abstract: A process is provided for metallating ethylene polymers which have polymerized therein a minor amount of nonconjugated diene. Metallation is accomplished with a blend of three metallating reagents: (a) an alkyllithium compound; (b) a potassium alkoxide; and (c) a chelating tertiary diamine. The metallated polymers so prepared may be reacted with one or more anionically polymerizable monomers to form graft polymers or with a reagent such as carbon dioxide to form a functionalized polymer. When the anionically polymerizable monomer has two or more polymerizable sites, the metallated polymer is reacted with a modifying compound such as alpha-methylstyrene before it is reacted with the monomer(s). Certain of the graft polymers behave as thermoplastic elastomers whereas others are thermoplastic. The blend of metallating reagents may be used with any polymer having partial or complete unsaturation.

Abstract: The present invention relates to an impact resistant polymeric composition comprising a polyamide and a thermally stable modified selectively hydrogenated high 1,2 content block copolymer wherein at least one graftable functional molecule is grafted to the block copolymer in the vinylarene block.

Abstract: Adhesive compositions comprising tackified star block copolymer having at least 12 block copolymer arms are provided. Sheet materials coated with the adhesive composition are also provided.

Abstract: A block copolymer of propylene is produced by using propylene itself as a liquid medium, conducting continuous polymerization (former-stage polymerization) of propylene alone or propylene and a small amount of ethylene at first and then conducting batchwise copolymerization (latter-stage polymerization) of ethylene and propylene. The amount of an activity improver to be added to a polymerization tank for the latter-stage polymerization and/or the polymerization time of the latter-stage polymerization are controlled in accordance with the amount of a slurry transferred from a polymerization tank for the former-stage polymerization to the polymerization tank for the latter-stage polymerization so as to maintain the ratio of the amount of the polymer polymerized by the former-stage polymerization to the amount of the polymer polymerized by the latter-stage polymerization constant in the block copolymer.

Abstract: This invention provides an improvement in anionic polymerization processes which comprise both a batch polymerization step to form and partially grow living polymer chains and a subsequent continuous or semi-continuous step in which growth of the chains is continued. For purposes of this improvement, the transition to the continuous or semi-continuous step takes place before the molar concentration of monomer in the batch polymerization step is depleted to a level below that of the living chains. Anionic polymerization processes are recognized as particularly useful for the production of polymers having narrow molecular weight distributions. Practice under the invention is found to enhance the narrow distribution of the polymer product by controlling thermal die-out of chains which has occurred in conventional processes during the transition from batch to continuous or semi-continuous polymerization steps.

Abstract: A process is provided for metallating ethylene polymers which have polymerized therein a minor amount of nonconjugated diene. Metallation is accomplished with a blend of three metallating reagents: (a) an alkyllithium compound; (b) a potassium alkoxide; and (c) a chelating tertiary diamine. The metallated polymers so prepared may be reacted with one or more anionically polymerizable monomers to form graft polymers or with a reagent such as carbon dioxide to form a functionalized polymer. When the anionically polymerizable monomer has two or more polymerizable sites, the metallated polymer is reacted with a modifying compound such as alpha-methylstyrene before it is reacted with the monomer(s). Certain of the graft polymers behave as thermoplastic elastomers whereas others are thermoplastic. The blend of metallating reagents may be used with any polymer having partial or complete unsaturation.

Abstract: Novel, reactive block copolymers are claimed having the structures AB, ABA, (AB).sub.m Y, (AB).sub.n Y--A).sub.o and (AB).sub.n Y--B).sub.p where each A block is a copolymer block of a monoalkenyl arene monomer and a benzocyclobutene monomer of the formula ##STR1## where R is H or CH.sub.3 and each B block is a polymerized conjugated diene hydrocarbon block.

Abstract: The present invention is directed to a process for preparing polymers which may be coupled (reacted) at temperatures above about 200.degree. C., the process comprising first reacting monomer(s) selected from conjugated dienes and monoalkenyl arenes with an organomonolithium initiator and then reacting the resulting polymeric arms (P-Li) with certain arylcyclobutene monomers. These arylcyclobutene monomers have the formula ##STR1## where X is an alkylene or arylene group, Z is an arylcyclobutene group, R is selected from the group consisting of aryl groups, alkyl groups, ##STR2## and H, and R.sup.1 is an aryl group or alkyl group.

Abstract: A process is provided for metallating crystalline ethylene polymers which have polymerized therein a minor amount of at least one nonconjugated diene and, optionally, a minor amount of at least one 1-olefin. Metallation is accomplished with an alkyllithium compound and at least one activating reagent after a slurry of the copolymer in a nonreactive, saturated, nonpolar hydrocarbon solvent is first heated to a temperature greater than 80.degree. Centigrade to provide the polymer with an expanded settling volume greater than its original settling volume. Metallation may be accomplished either at that temperature or at a lower temperature following cooling of the slurry. The activating reagents include potassium alkoxides, and chelating tertiary diamines. The metallated polymers so prepared may be reacted with (a) one or more anionically polymerizable monomers to form graft polymers or (b) a reagent such as carbon dioxide to form a functionalized polymer.

Abstract: Sequential charging of initiator and monomers in a multistage solution polymerization process involving conjugated diene and monovinylaromatic monomers wherein the initial and final charges are monovinylaromatic monomer results in the production of polymodal linear block copolymers with terminal resinous blocks. A typical 6-stage charge sequence is as follows: stage 1: (S.sub.i); stage 2: (S.sub.i); stage 3: (B); stage 4: (S.sub.i); stage 5: (B) and stage 6: (S) wherein (S.sub.i) is monovinylaromatic monomer and initiator, (B) is conjugated diene monomer and (S) is monovinylaromatic monomer. At each stage, polymerization is allowed to continue until no free monomer is present.The polymodal block copolymer products comprise high, medium and low molecular weight species designated, respectively, as S.sub.1 -S.sub.2 -B.sub.1 -S.sub.3 -B.sub.2 -S.sub.4 ; S.sub.2 -B.sub.1 -S.sub.3 -B.sub.2 -S.sub.4 ; and S.sub.3 -B.sub.2 -S.sub.4 wherein S.sub.1, S.sub.2, S.sub.3 and S.sub.

Abstract: Sequential charging of initiator and monomers in a multistage solution polymerization process involving conjugated diene and monovinylaromatic monomers wherein the final charge is a mixture of these monomers results in the production of resinous polymodal linear block copolymers each with a terminal tapered block. A typical 5-stage charge sequence is as follows: Stage 1: (S.sub.i); Stage 2: (S.sub.i); Stage 3: (B); Stage 4: (S.sub.i); Stage 5: (S+B) wherein (S.sub.i) is monovinylaromatic monomer and initiator; (B) is conjugated diene monomer and (S+B) is monovinylaromatic monomer and conjugated diene monomer. At each stage, polymerization is allowed to continue until no free monomer is present.The trimodal block copolymer products comprise high, medium and low molecular weight species designated, respectively, as S.sub.1 -S.sub.2 -B.sub.1 -S.sub.3 -B.sub.2 .fwdarw.S.sub.4 ; S.sub.2 -B.sub.1 -S.sub.3 -B.sub.2 .fwdarw.S.sub.4 ; and S.sub.3 -B.sub.2 .fwdarw.S.sub.4 wherein S.sub.1, S.sub.2 and S.sub.

Abstract: Graft copolymers are prepared by means of a two-step polymerization process, in emulsion: in the first step, a vinylaromatic monomer and an acryl or metacryl monomer are grafted on a monomodal polybutadiene latex constituted of particles of diameter comprised within the range of from 800 to 2500 .ANG.. The polymerization/grafting reaction is continued up to a 70-90% conversion, at which time a further portion of monomodal polybutadiene is added, together with further amounts of said monomers, always in emulsion.

Abstract: Novel, reactive, selectively hydrogenated block copolymers are claimed having the structures AB, ABA, (AB).sub.m Y, (AB).sub.n Y--A).sub.o and (AB).sub.n Y--B).sub.p where each A block is a copolymer block of a monoalkenyl arene monomer and a benzocyclobutene monomer of the formula ##STR1## where R is H or CH.sub.3 and each B block is a substantially completely hydrogenated conjugated diene polymer block.

Abstract: The invention relates to partially hydrophilic, non-ionic crosslinked copolymers.These copolymers consist of a crosslinked hydrophobic backbone having a high mechanical strength, and of non-ionic hydrophilic chains grafted selectively onto the backbone.The copolymers are useful for size exclusion chromatography in an aqueous medium.

Abstract: An alternate procedure for preparing multilithium initiators using DVB has been developed in order to achieve better control over the specific number of anionic sites per initiator molecule and to prepare star-block copolymers having a pre-determined number of branches. The process consists of 3 distinct steps; oligomerization, activation and polymer growth. The initial step involves the oligomerization of DVB yielding a mini-block having a predetermined number of pendant vinyl groups using a monofunctional initiator such as polystyryllithium. This is quickly followed by activation of the pendant vinyl groups using s-butyllithium prior to polymer growth.

Abstract: Carburetor detergency properties of hydrocarbon fuels are provided by nitrogen-containing organic compound-grafted, hydrogenated conjugated diene-monovinylarene copolymers.