Abstract: The process and catalyst system of this invention can be utilized to synthesize polybutadiene rubber having a high trans content and a low melting point by solution polymerization. The trans-polybutadiene rubber made by the process of this invention can be utilized in tire tread rubbers that exhibit outstanding wear characteristics. More importantly, the trans-polybutadiene rubber of this invention can be easily processed because of its low level of crystallinity. In fact, the trans-polybutadiene made by the process of this invention does not need to be heated in a “hot-house” before being used in making rubber compounds.

Abstract: Superabsorbent polymers having a slow rate of absorption, and a process for their preparation. The superabsorbent polymer has a slow rate of absorption, is crosslinked with a covalent crosslinking agent and the metal of a polyvalent metal coordination compound, has the metal of the coordination compound distributed essentially homogeneously throughout the polymer, and has an Absorption Rate Index of at least about 5 minutes. Prepare water-swellable, water-insoluble polymer particles having a slow rate of water absorption by polymerizing a monomer in the presence of a covalent crosslinking agent and a polyvalent metal coordination compound under conditions such that there is formed a polymer having reversible cationic crosslinks and such that the metal is distributed essentially homogeneously throughout the polymer particles.

Abstract: A process for preparing a solution of high molecular weight polymers of conjugated dienes in a vinylaromatic hydrocarbon by anionic polymerization of the diene in the presence of an alkyllithium as catalyst and a process for preparing impact-modified polymers of vinylaromatic compounds is described. The first process comprises firstly polymerizing the diene in solution in an aromatic hydrocarbon which is free of ethylenic double bonds to a molecular weight below about 105, then adding a trialkylaluminum in a molar excess relative to the alkyllithium, diluting the solution obtained with the vinylaromatic compound and then coupling the polydiene with a polyepoxide or an alkyl (meth)acrylate to give a high molecular weight polymer. The solution obtained in this way is further processed to give an impact-modified polymer of a vinylaromatic hydrocarbon by polymerizing the solution prepared as described, if desired after addition of further amounts of a vinylaromatic compound, in a manner known per se.

Abstract: The present invention is an improvement in a method of anionically polymerizing monomers by contacting them with an anionic polymerization initiator which is an organo-substituted alkali metal compound in the presence of low amounts of an accelerator/promoter and/or a highly active microstructure modifier. The improvement comprises adding from 0.1 to 1.0 equivalents of a metal alkyl compound per equivalent of alkali metal initiator wherein alkyl groups of the metal alkyl compound are chosen so that they will not exchange with the organo substituents of the alkali metal compound. The preferred initiator for use herein is the sec-butyl lithium adduct of diisopropenyl benzene and the preferred metal alkyl is triethyl aluminum.

Abstract: In a process for the homopolymerization of vinylaromatic monomers or the copolymerization of vinylaromatic monomers and dienes, the monomers are polymerized in the presence of at least one alkali metal organyl, at least one magnesium organyl and at least one aluminum organyl. The invention also provides an initiator composition for carrying out the process.

Abstract: The present invention is an improvement upon the known method of anionically polymerizing monomers by contacting the monomers with an anionic polymerization initiator which is an organo-substituted alkali metal compound. The improvement comprises decreasing the viscosity of the polymer cement by adding at least 0.01 equivalent of a metal alkyl compound per equivalent of alkali metal initiator if the metal alkyl is added before or at the beginning of polymerization. If the metal alkyl is added during the polymerization or after but before the living polymer is terminated, then at least 0.01 equivalent of the metal alkyl compound per equivalent of living polymer chain ends is should be used. The alkyl groups of the metal alkyl are chosen such that they do not exchange with the organo substituents of the alkali metal, which can be the living polymer chain ends or the organo substituents of the initiator.

Abstract: A cyclic olefin polymer having a small content of a catalyst residue, a production process for the same and use of the same as an optical material. Catalysts used for polymerization and/or hydrogenation reaction for forming the cyclic olefin polymer are decomposed efficiently by adding at least one compound selected from the group consisting of an &agr;-oxyacid and &bgr;-oxyacid having one hydroxyl group and one carboxyl group in the molecule and derivatives obtained by substituting hydroxyl group thereof by an alkoxyl group, and the decomposition products are removed by rendering them insoluble in a reaction solvent used for the polymerization and/or hydrogenation reaction and precipitating them efficiently.

Abstract: A process for the preparation of an acrylic acid ester polymer, includes carrying out polymerization of an acrylic acid ester or block copolymerization of an acrylic acid ester and another (meth)acrylic monomer in the presence of an organolithium compound and an organoaluminum compound represented by the following formula (I):

Abstract: In a process for the preparation of block copolymers from vinylaromatic monomers and dienes, the monomers are polymerized in the presence of at least one alkali metal organyl or alkali metal alkoxide and at least one magnesium, aluminum or zinc organyl.

Abstract: In a process for the homopolymerization of vinylaromatic monomers or the copolymerization of vinylaromatic monomers and dienes in the presence of at least one alkali metal compound and at least one compound of an element of group 3a of the Periodic Table of the elements, the compounds contain, based on the sum of molar equivalents of alkali metal and elements of group 3a, in each case a) from 0.1 to 3.9 molar equivalents of oxygen, sulfur, nitrogen or phosphorus and b) from 0.1 to 3.9 molar equivalents of an organyl ligand.

Abstract: A process for the preparation of an acrylic acid ester polymer, includes carrying out polymerization of an acrylic acid ester or block copolymerization of an acrylic acid ester and another (meth)acrylic monomer in the presence of an organolithium compound and an organoaluminum compound represented by the following formula (I): AlR1R2R3  (I) wherein R1 represents an alkyl group having at least 3 carbon atoms, an alkoxy group having at least 3 carbon atoms or an aryloxy group, R2 and R3 each independently represent an aryloxy group or may be coupled together to form an arylenedioxy group. The process makes it possible to increase the reaction rate and living properties upon polymerization and increase the block formation efficiency upon block copolymerization.

Abstract: The anionic polymerization of dienes or copolymers of dienes and vinylaromatic monomers in a vinylaromatic monomer or monomer mixture to give homopolydienes or copolymers or mixed homopolydienes and copolymers is carried out in the presence of a metal alkyl or aryl of an element having a valence of at least two without addition of Lewis bases.

Abstract: Disclosed are a process for the preparation of an initiator composition comprising an alkali metal organyl and an aluminum organyl and a process for the polymerization of anionically polymerizable monomers.

Abstract: A Group 4 transition metal complex containing a boron or aluminum bridging group containing a nitrogen containing electron donating group, especially an amido group.

Abstract: Homopolymers, copolymers or block copolymers are prepared by anionic polymerization of acrylates and/or methacrylates in the presence of an initiator composition containing A) an organic alkali metal compound, B) an organic aluminum compound and C) an additive which forms a complex with the alkali metal cation and is selected from the group consisting of open-chain ethers having at least two ether oxygen atoms, macrocyclic ethers and cryptands, or from the group consisting of quaternary cations of the general formula I  where A is N, P, As or Sb and Ra, Rb, Rc and Rd, independently of one another, are each unsubstituted or substituted alkyl, cycloalkyl, aralkyl or aryl, where two neighboring radicals, together with the heteroatom A, may form a 5- or 6-membered heterocyclic structure which may contain one or two further heteroatoms selected from nitrogen, oxygen and sulfur atoms.

Abstract: Thermoplastic cycloolefin copolymers (COCs) having high tear strength and low optical attenuation, a process for their preparation, and their use as optical waveguides (optical fibers).

Abstract: This invention relates to a multifunctional organic alkali metal initiator for the preparation of various kinds of star polymers by anionic polymerization, a process for making the initiator, a process using said initiator for making star polymers and the polymers obtained. The initiator can be represented by the formula: M.sub.a (RMe).sub.b, wherein M is selected from Sn, Ti, Al, Si and/or B; R is a hydrocarbyl group containing 8-100 carbon atoms, a=1-3, b=2.5-6.5, Me is an alkali metal which may be selected from Na and Li. The initiator was synthesized by reacting an organic alkali metal with a conjugated diene and/or a mono-olefin monomer, and then adding hetero-atom containing halide. The star polymer obtained has a radial molecular structure consisting of several macromolecular chain arms radiating from the initiator core, and its molecular weight distribution expressed by GPC presents a uniform singlet.

Abstract: The preparation of di- or polyfunctional polymers by anionic polymerization using functionalized initiators having the structure R.sup.1 R.sup.2 R.sup.3 Si--A--B, wherein each R is methyl and A is a hydrocarbon bridging group containing from 1 to 25 carbon atoms, and B is an alkali metal, is improved when polymerization occurs in the presence of a polymerization termination inhibitor which is a metal alkyl which has been added at a concentration to afford a molar ratio of the termination inhibitor to living polymer chain ends of about 0.1:1 to about 10:1.

Abstract: Polyacrylates based on alkyl acrylates or alkyl alkylacrylates or mixtures thereof as monomers are prepared in the presence of an initiator composition containing an alkali metal ester enolate and an organic aluminum compound or a mixture thereof, by a process in which an ester which differs from the monomers is present in the initiator composition, the carbon atom .alpha. to the ester group having no acidic proton.

Abstract: The process of this invention can be utilized to synthesize polymers having a high trans microstructure. The polymers which can be prepared utilizing the procedure of this invention include high trans-1,4-polybutadiene, styrene-isoprene-butadiene terpolymers with high trans-1,4-polybutadiene microstructures, high trans-isoprene-butadiene copolymers, and styrene-butadiene copolymers having high trans-1,4-polybutadiene microstructures. Such polymers can be utilized in tire tread rubber compounds which exhibit improved wear characteristics, tear resistance and low temperature performance characteristics. This invention more specifically reveals a process for synthesizing a high trans polymer which comprises adding (a) at least one organolithium initiator or organomagnesium initiator, (b) an organoaluminum compound, (c) a barium alkoxide, and (d) an organozinc compound to a polymerization medium which is comprised of an organic solvent and at least one conjugated diene monomer.

Abstract: Addition polymers derived from norbornene-functional monomers are terminated with an olefinic moiety derived from a chain transfer agent selected from a compound having a terminal olefinic double bond between adjacent carbon atoms, excluding styrenes, vinyl ethers, and conjugated dienes and at least one of said carbon atoms has two hydrogen atoms attached thereto. The addition polymers of this invention are prepared from a single or multicomponent catalyst system including a Group VIII metal ion source. The catalyst systems are unique in that they catalyze the insertion of the chain transfer agent exclusively at a terminal end of the polymer chain.

Abstract: The invention concerns the anionic polymerization of alkyl methacrylate in the presence of a priming system. The priming system comprises an organolithium primer and an organic compound of aluminum and pyridine. This priming system allows better polymerization control.

Abstract: Addition polymers derived from norbornene-functional monomers are terminated with an olefinic moiety derived from a chain transfer agent selected from a compound having a terminal olefinic double bond between adjacent carbon atoms, excluding styrenes, vinyl ethers, and conjugated dienes and at least one of said carbon atoms has two hydrogen atoms attached thereto. The addition polymers of this invention are prepared from a single or multicomponent catalyst system including a Group VIII metal ion source. The catalyst systems are unique in that they catalyze the insertion of the chain transfer agent exclusively at a terminal end of the polymer chain.

Abstract: Addition polymers derived from norbornene-functional monomers are terminated with an olefinic moiety derived from a chain transfer agent selected from a compound having a terminal olefinic double bond between adjacent carbon atoms, excluding styrenes, vinyl ethers, and conjugated dienes and at least one of said carbon atoms has two hydrogen atoms attached thereto. The addition polymers of this invention are prepared from a single or multicomponent catalyst system including a Group VIII metal ion source. The catalyst systems are unique in that they catalyze the insertion of the chain transfer agent exclusively at a terminal end of the polymer chain.

Abstract: Disclosed herein are a novel process for the preparation of alkylsilanes and alkenyl silanes by hydrosilylation of their corresponding silanes and unsaturated hydrocarbons in the presence or absence of a catalyst, a process for the preparation of polyalkenylsilanes (some of which are novel high molecular compounds) by the anionic coordination polymerization, radical polymerization or ionic polymerization of the alkenylsilanes, and a process for the production of silicon carbide by using these polyalkenylsilanes as prepolymers.

Abstract: A single component ionic catalyst consists essentially of an organonickel complex cation, and a weakly coordinating neutral counteranion. The cation is a neutral bidentate ligand removably attached to a Group VIII transition metal in an organometal complex. The ligand is easily displaced by a norbornene-type (NB-type) monomer in an insertion reaction which results in an unexpectedly facile addition polymerization. A NB-type monomer includes NB or substituted NB, or a multi-ringed cycloolefin having more than three rings in which one or more of the rings has a structure derived from NB, and a ring may have an alicyclic alkyl, alkylene or alkylidene substituent. The insertion reaction results in the formation of a unique propagating species more soluble in a polar than in a non-polar solvent and devoid of an available .beta.-hydrogen for termination. The ensuing propagation of a polymer chain proceeds without measurable unsaturation.

Abstract: Mono and diallyl amines are silylated to protect them from reacting with high activity Ziegler-Natta catalysts so they may be copolymerized with propylene; also disclosed are copolymers of such amines with propylene and their hydrolyzed or alcoholyzed counterparts.

Abstract: Liquid telechelic polymers are made from dienes and are produced via anionic polymerization. While having low molecular weight, for example less than 15,000, the telechelic polymers are generally gel-free, have high amounts of trans-1,4 structure, low vinyl unsaturation and low bulk viscosities. The liquid telechelic polymers are made utilizing a trimetallic initiator comprised of (1) an organopolylithium compound and (2) a complex of a trialiphatic substituted aluminum compound or derivative thereof and a barium salt of an organic alcohol.

Abstract: A process for addition polymerization of vinylic (in particular methacrylic) monomers at a temperature in the range of -20.degree. to 60.degree. c., in the presence of a catalyst comprising:(a) a first component of empirical formula (I):MT (I)whereinM is an alkali metal atom; andT is bulky hydrocarbyl which contains at least 4 carbon atoms and is optionally substituted by one or more pendent substituents, or hetero-substituted hydrocarbyl, each of which is inert in the process conditions; and(b) a (co-catalyst) second component comprising a compound of empirical formula (II):Q(X.sub.m) (Y.sub.n) Zp (II)whereinQ is Al, B or Zn;m, n and p are each 0 or an integer such that (m+n+p)=2 or 3 (depending on the appropriate valency of Q; andX, Y and Z are each independently optionally substituted bulky hydrocarbyl, orX and Y together are optionally substituted hydrocarbadiyl, and Z is optionally substituted bulky hydrocarbyl,all of which groups are inert in the process conditions.

Abstract: Disclosed is a linear acrylonitrile polymer having a viscosity average molecular weight of at least 50,000, which has a stereoregularity such that the polymer satisfies requirements of I>0.4 and (I+3S)>0.95, wherein I represents the fraction of the isotactic triad and S represents the fraction of the syndiotactic triad. A shaped article is made from a composition comprised of the linear acrylonitrile polymer and a solvent or plasticizer which is selected from a protonic acid and an aqueous solution thereof, an aqueous inorganic salt solution, and a mixture of an organic solvent and an inorganic salt. The fiber made therefrom has an enhanced drawability.

Abstract: A process for producing a high trans low vinyl conjugated diene (co)polymer, comprising polymerizing at least one conjugated diene alone or in combination with at least one alkenyl compound using a catalyst composition comprising (a) a barium compound, (b) an organoaluminum compound, (c) an organolithium compound and (d) a hydroxyl group-containing organic compound. This process enables the easy production of a high trans low vinyl conjugated diene (co)polymer having a high trans 1,4 bond content, a low vinyl bond content and a high molecular weight, at a high polymerization activity.

Abstract: Liquid telechelic polymers are made from dienes and are produced via anionic polymerization. While having low molecular weight, for example less than 15,000, the telechelic polymers are generally gel-free, have high amounts of trans-1,4 structure, low vinyl unsaturation and low bulk viscosities. The liquid telechelic polymers are made utilizing a trimetallic initiator comprised of (1) an organopolylithium compound and (2) a complex of a trialiphatic substituted aluminum compound or derivative thereof and a barium salt of an organic alcohol.

Abstract: A highly active anionic polymerization catalyst prepares butadiene polymers having a high 1,4-trans-dienyl content, the catalyst containing an organolithium compound, a barium, strontium or calcium compound, and trialkylaluminum compounds having at least 13 carbon atoms per molecule.

Abstract: A catalyst composition for polymerizing a conjugated diene which comprises the following (a), (b) and (c) components:(a) an organolithium-aluminum compound represented by the formula:LiAlR.sup.1 R.sup.2 R.sup.3 R.sup.4(b) an organobarium-aluminum compound represented by the formula:Ba(AlR.sup.1 R.sup.2 R.sup.3 R.sup.4).sub.2 or Ba[AlR.sup.1 R.sup.2 R.sup.3 (OR.sup.4)].sub.2(c) a lithium alkoxide represented by the formula:LiOR.sup.5The conjugated diene polymer or copolymer obtained by polymerizing a conjugated diene alone or in combination with other monomer with the above catalyst composition in an inert organic solvent has a high trans-1,4 bond content, a low vinyl bond content and a low cis-1,4 bond content.

Abstract: A process is disclosed for treatment of alkyl methacrylate monomers for subsequent polymerization by an anionic initiator to produce a polymer with a molecular weight distribution between about 1.20 and about 1.01. The process involves treatment of the monomer with an aluminum hydrocarbyl or boron hydrocarbyl in quantities which permit polymerization in the presence of the by-products of the reaction between the impurities and the aluminum hydrocarbyl or boron hydrocarbyl.

Abstract: Conjugated dienes, in particular 1,3-conjugated dienes, can be polymerized or copolymerized using the catalyst system of this invention to polymers wherein the amount of 1,2-structure contained in the polymer is increased, and polymers can be prepared containing varying amounts of 1,2-structure as desired. Such desirable results can be obtained in accordance with the process of the present invention for polymerizing conjugated diene monomers which comprises the use of a catalyst system which comprises (a) at least one anionic initiator based on lithium, and (b) a modifier composition comprising at least one cyclic acetal of a glyoxal. ##STR1## wherein R and R' are each independently hydrogen, alkyl or aryl groups, and each A is independently an alkylene or an oxyalkylene group.In another embodiment, the catalyst system also contains at least one co-initiator selected from the group consisting of organomagnesium compounds, organoaluminum compounds, or mixtures thereof.

Abstract: An optically active polymer is obtained by polymerizing a vinyl monomer in the presence of a catalyst which comprises an asymmetric ligand compound of the formula (I) or (II): ##STR1## in which R.sub.1 and R.sub.4 each are --O--R.sub.7, --S--R.sub.7, ##STR2## R.sub.2, R.sub.3, R.sub.5, R.sub.6, R.sub.7 and R.sub.8 each are an alkyl group having 1 to 10 carbon atoms; X is hydrogen, an alkyl group having 1 to 10 carbon atoms or a halogen; and n is a number of 1 to 4; and an anionic initiator to form a complex with said ligand compound.

Abstract: A process and catalyst system is disclosed herein for the preparation of (co)polymers having a 1,2-microstructure ranging between about 20 and about 65 percent. These (co)polymers are prepared in a hydrocarbon or non-polar solvent from a monomer system which contains at least one 1,3-diene monomer and optionally other copolymerizable monomers. The catalyst system which is employed in the production of the (co)polymer is a combination of (1) an anionic initiator based on lithium; (2) a dialkyl magnesium compound or a trialkyl aluminum compound or a mixture thereof; and (3) a phosphine oxide modifier which is substituted with three saturated heterocyclic rings, each hetero ring containing one nitrogen atom and either four, five or six carbon atoms.

Abstract: Conjugated dienes, in particular 1,3-conjugated dienes, can be polymerized or copolymerized using the catalyst system of this invention to polymers wherein the amount of 1,2-structure contained in the polymer is increased, and polymers can be prepared containing varying amounts of 1,2-structure as desired. Such desirable results can be obtained in accordance with the process of the present invention for polymerizing conjugated diene monomers which comprises the use of a catalyst system which comprises (a) at least one anionic initiator based on lithium, and (b) a modifier composition comprising at least one cyclic acetal of a glyoxal. ##STR1## wherein R and R' are each independently hydrogen, alkyl or aryl groups, and each A is independently an alkylene or an oxyalkylene group.In another embodiment, the catalyst system also contains at least one co-initiator selected from the group consisting of organomagnesium compounds, organoaluminum compounds, or mixtures thereof.

Abstract: A process for the anionic polymerization of a conjugated 1,3-diene in a polar solvent consists of contacting the 1,3-diene with an organo alkali or alkaline earth metal initiator and a sterically hindered Lewis acid, allowing the 1,3-diene to polymerize in the polar solvent and terminating the polymerization reaction. Preferably the Lewis acid is a substituted triaryl derivative of a Group III element, especially boron. However in certain cases (e.g. where the aryl derivative itself is large) the Lewis acid may be an unsubstituted triaryl derivative of a Group III element. Suitable Lewis acids include trimesityl boron and tri (2,6-dimethylphenyl) boron. In preferred embodiments of the present process the 1,3-diene is butadiene, the polar solvent is tetrahydrofuran and the initiator is a difunctional initiator, especially an electron transfer reagent.

Abstract: A process and catalyst system is disclosed herein for the preparation of (co)polymers having a 1,2-microstructure ranging between about 20 and about 65 percent. These (co)polymers are prepared in a hydrocarbon or non-polar solvent from a monomer system which contains at least one 1,3-diene monomer and optionally other copolymerizable monomers. The catalyst system which is employed in the production of the (co)polymer is a combination of (1) an anionic initiator based on lithium; (2) a dialkyl magnesium compound or a trialkyl aluminum compound or a mixture thereof; and (3) a phosphine oxide modifier which is substituted with three saturated heterocyclic rings, each hetero ring containing one nitrogen atom and either four, five or six carbon atoms.

Abstract: A process and catalyst system is disclosed herein for the preparation of (co)polymers having a 1,2-microstructure of between 20 and 95 percent. These (co)polymers are prepared in a hydrocarbon or other non-polar solvent from a monomer system which contains at least one 1,3-diene monomer. The catalyst system which is employed in the production of the (co)polymers of the present invention is a combination of (1) an anionic initiator based on lithium; (2) an alkyl magnesium compound or an alkyl aluminum compound or a mixture thereof; and (3) a modifier compound selected from the group consisting of linear and cyclic oligomeric oxolanyl alkanes.

Abstract: A process for producing polymers of a conjugated diene, copolymers of a conjugated diene and another conjugated diene, or copolymers of conjugated diene and a vinyl aromatic hydrocarbon, which comprises polymerizing the corresponding monomers in the presence of a complex initiator consisting of components (a) and (b) described below, or (a) and (b) together with one or more components selected from components (c) and (d);(a) An organic compound of barium, strontium or calcium;(b) An organolithium-beryllium compound or an organolithiummagnesium compound;(c) An organolithium compound, an organoberyllium compound or an organomagnesium compound; and(d) An organoaluminum compound or an organozinc compound.The polymers of a conjugated diene containing relatively high trans-1,4 linkage, or the copolymers of a conjugated diene and a vinyl aromatic compound highly randomized and having high bound styrene and high trans-1,4 linkage can be produced at good yields.

Abstract: An isoprene-butadiene copolymer rubber having improved processing properties which comprises a microstructure of the butadiene portion having from 70% to 90% of trans-1,4 linkage and from 2% to 8% of vinyl linkage, an isoprene content of from 3 to 25 wt %, and a styrene content of from 0 to 30 wt %, said copolymer rubber having a Mooney Viscosity of from 30 to 150, and a molecular weight distribution, Mw/Mn of from 1.2 to 3.5, said rubber, in the unelongated state, not showing a melting point measured by the differential calorimeter analysis method. The copolymer rubber of the present invention can be used for tires, for example, a tread and a carcass or for other rubber uses.

Abstract: Continuous solution polymerization in an open type reactor of one or more conjugated dienes or of one or more conjugated dienes with one or more vinyl aromatic compounds, initiated by an organolithium initiator, without clogging of the reactor due to gel formation can be achieved by conducting the polymerization in the presence of a deactivating system which inhibits the formation of gels.

Abstract: Homopolymers of conjugated dienes and copolymers of conjugated dienes with other conjugated dienes or with vinyl aromatic compounds having an elastomeric character are prepared by use of a catalytic system formed of the reaction product of (a) an organometallic compound of a metal of Group IIIA of the Mendeleev periodic table of elements with (b) at least one electron-donor compound containing at least one hetero-atom.

Abstract: Homopolymers of conjugated dienes and copolymers of conjugated dienes with other conjugated dienes or with vinyl aromatic compounds having an elastomeric character are prepared by use of a catalytic system formed of the reaction product of (a) an organometallic compound of a metal of Group IIIA of the Mendeleev periodic table of elements with (b) at least one electron-donor compound containing at least one hetero-atom.

Abstract: Homopolymers of conjugated dienes and copolymers of conjugated dienes with other conjugated dienes or with vinyl aromatic compounds having an elastomeric character are prepared by use of a catalytic system formed of the reaction product of (a) an organometallic compound of a metal of Group IIIA of the Mendeleev periodic table of elements with (b) at least one electron-donor compound containing at least one hetero-atom.

Abstract: Continuous solution polymerization in an open type reactor of one or more conjugated dienes or of one or more conjugated dienes with one or more vinyl aromatic compounds, initiated by an organolithium initiator, without clogging of the reactor due to gel formation can be achieved by conducting the polymerization in the presence of a deactivating system which inhibits the formation of gels.

Abstract: Continuous solution polymerizaton in an open type reactor of one or more conjugated dienes or of one or more conjugated dienes with one or more vinyl aromatic compounds, initiated by an organolithium initiator, without clogging of the reactor due to gel formation can be achieved by conducting the polymerization in the presence of a deactivating system which inhibits the formation of gels.