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 molding material as based on from 60 to 98% by weight of a hard matrix A comprising polymerized or copolymerized units of at least one vinylaromatic monomer or at least one vinylaromatic monomer and at least one polar comonomer and from 2 to 40% by weight, the percentages in each case being based on the molding material comprising A and B, of a soft phase B formed from a hydrogenated or unhydrogenated block copolymer prepared by anionic polymerization and comprising a vinylaromatic monomer V and a diene D, having at least one random or quasi-random block (V/D) of vinylaromatic monomer and diene and containing from 10 to 80% by weight, based on the soft phase B, of occlusions of matrix material (a) formed during the polymerization of the hard matrix A in the presence of the block rubber, and said molding material is used for the production of films, sheets or moldings.

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: Anionic polymerization is used for the preparation of reaction mixtures comprising homopolymers, copolymers or block copolymers, and of homopolymers, copolymers and block copolymers which comprise acrylates or methacrylates or acrylates and methacrylates, wherein olefinically unsaturated compounds which are not acrylate or methacrylate derivatives are employed as solvent or as solvent component.

Abstract: A process for the reaction of an organic compound in the presence of a catalyst comprising, as active metal, ruthenium alone or together with at least one Group Ib, VIIb, or VIIIb metal in an amount of from 0.01 to 30 wt %, based on the total weight of the catalyst, applied to a support, wherein from 10 to 50% of the pore volume of the support comprises macropores having a pore diameter in the range of from 50 nm to 10,000 nm and from 50 to 90% of the pore volume of the support comprises mesopores having a pore diameter in the range of from 2 to 50 nm, the sum of said pore volumes being 100%, and said catalyst as such.

Abstract: A thermoplastic molding material containing A) from 5 to 95% by weight of a vinylaromatic polymer having a syndiotactic structure and B) from 5 to 95% by weight of a copolymer of a vinylaromatic monomer and 1,1-diphenylethylene or its derivatives which may be substituted on the aromatic rings by alkyl of up to 22 carbon atoms.

Abstract: Preparation of rubber-modified molding compositions comprises a1) anionic polymerization of a mixture (A) comprising acrylate derivatives or methacrylate derivatives or acrylate derivatives and methacrylate derivatives and a solvent, if desired comprising olefinically unsaturated compounds which are not an acrylate derivative or a methacrylate derivative, or a2) sequential anionic polymerization of acrylate derivatives or methacrylate derivatives or acrylate derivatives and methacrylate derivatives in the presence of a solvent which, if desired, comprises olefinically unsaturated compounds to give block copolymers, and b) subjecting the reaction mixture obtained in a1) or a2) or a1) and a2) to a free-radical-initiated polymerization, if desired after the addition of unsaturated compounds.

Abstract: A process for the reaction of an organic compound in the presence of a catalyst comprising, as active metal, ruthenium alone or together with at least one Group Ib, VIIb, or VIIIb metal in an amount of from 0.01 to 30 wt %, based on the total weight of the catalyst, applied to a support, wherein from 10 to 50% of the pore volume of the support comprises macropores having a pore diameter in the range of from 50 nm to 10,000 nm and from 50 to 90% of the pore volume of the support comprises mesopores having a pore diameter in the range of from 2 to 50 nm, the sum of said pore volumes being 100%, and said catalyst as such.

Abstract: Elastomeric block copolymers comprising at least one hard block A composed of styrene monomers and at least one elastomeric block (B/A) composed of styrene monomers and dienes, the glass transition temperature Tg of the block A being more than 25° C. and that of block (B/A) being less than 25° C. and the phase volume ratio of block A to block (B/A) being chosen so that the proportion of the hard phase in the total block copolymer is from 1 to 40% by volume and the amount by weight of the diene is less than 50% by weight, and the relative proportion of 1,2 linkages of the polydiene, based on the sum of 1,2- and 1,4-cis/trans linkages, being below 15%, are prepared by anionic polymerization by means of a lithium alkyl in a nonpolar solvent in the presence of a soluble potassium salt and are used for the production of shaped articles.

Abstract: Thermoplastic molding compositions comprise:______________________________________ A) from 20 to 96% by weight of star polymers obtainable by polymerizing vinylaromatic monomers with a branched monomer building block which contains at least two vinylaromatic functions, B) from 3 to 50% by weight of copolymers comprising vinylaromatic monomers, 1,1-diphenylethylene and, if desired, dienes, C) from 1 to 15% by weight of polyarylene ethers, D) from 0 to 5% by weight of nucleating agents, E) from 0 to 5% by weight of antioxidants, F) from 0 to 5% by weight of stabilizers, and G) from 0 to 50% by weight of fibrous or particulate fillers.

Abstract: The present invention concerns a novel method for preparing polymers (preferably (meth)acrylate polymers and copolymers) having a narrow molecular weight distribution by metal-free anionic polymerization in the presence of a phosphonium cation containing at least one annellated aromatic ring as substituent on the phosphorous atom.

Abstract: An elastomeric block copolymer comprising at least one block A having polymerized units of a vinylaromatic monomer and forming a rigid phase and at least one elastomeric block B/A having polymerized units of both vinylaromatic monomers and of a diene and forming a flexible phase, and glass transition temperature Tg of the block A being above 25.degree. C. and that of the block B/A being below 25.degree. C. and the phase volume ratio of block A to block B/A being chosen so that the amount of the rigid phase in the total block copolymer is 1 to 40% by volume and the amount of the diene is less than 50% by weight.

Abstract: Abstract of the disclosure: A process is described for the continuous preparation of an impact-resistant molding material by anionic polymerization of styrene or another aromatic vinyl compound or mixtures thereof in the presence of a solvent and a block rubber, wherein the polymerization is carried out in at least 2 reaction vessels that together form a reactor cascade, the monomer stream being subdivided among the reaction vessels present, the living polymer chain ends being terminated in a conventional manner and the solvent being removed.

Abstract: A process for preparing diarylethanes of the general formula I ##STR1## where R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are each hydrogen or C.sub.1 -C.sub.8 -alkyl, by reacting aromatic compounds of the general formula II ##STR2## where R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 have the abovementioned meanings, with styrenes of the general formula III ##STR3## where R.sup.1 has the abovementioned meanings, at from -20 to 300.degree. C. under from 1 to 100 bar in the presence of heterogeneous catalysts, wherein beta-zeolites or mordenites are used as heterogeneous catalysts.

Abstract: In the preparation of a rubber-modified molding material, in a first stage, a first mixture (A) contains at least one alkyl acrylate or methacrylate (a) of the formula (I) ##STR1## where R.sup.1 is hydrogen or methyl and R.sup.2 is alkyl of 1 to 32 carbon atoms, at least one first monomer (b) which forms free radicals on thermal decomposition and, if required, a second monomer (c) or a plurality thereof is polymerized, preferably with free radicals, to give a rubber (B),in a second stage, the resulting rubber (B) is mixed with a third monomer (d) or a plurality thereof, preferably dissolved or swollen therein, to form a second mixture (C), andin a third stage, the second mixture (C) is polymerized with free radicals to give the rubber-modified molding material (D).

Abstract: In a process for preparing polystyrene by continuous anionic polymerization of styrene monomer by means of a catalyst based on a metal alkyl preferably in the presence of a solvent at a temperature in the range from 30 to 70.degree. C., the styrene monomer is fed to an essentially isothermally operated circulation reactor configured as a closed tube loop which has, for example, a specific cooling area of at least 50 m.sup.2 per m.sup.3 of reactor volume, with the circulation velocity of the reaction mixture and the residence time being set such that the monomer conversion reaches at least 50% and the polymerization is completed in an essentially backmixing-free tube reactor.

Abstract: In the preparation of a rubber-modified molding material, in a first stage, a first mixture (A) contains at least one alkyl acrylate or methacrylate (a) of the formula (I) ##STR1## where R.sup.1 is hydrogen or methyl and R.sup.2 is alkyl of 1 to 32 carbon atoms, a compound (b) of the formula (II) ##STR2## where R.sup.3 is hydrogen or methyl, R.sup.4 is hydrogen or alkyl of 1 to 8 carbon atoms, R.sup.5 is hydrogen or methyl and R.sup.6 is hydrogen or alkyl of 1 to 10 carbon atoms, preferably hydrogen, and, if required, a first monomer (c) or a plurality thereof is polymerized with free radicals to give a rubber (B),in a second stage, the resulting rubber (B) is mixed with a second monomer (d) or with a plurality thereof, preferably dissolved or swollen therein, to form a second mixture (C), andin a third stage, the second mixture (C) formed by mixing is polymerized with free radicals to give the rubber-modified molding material (D).

Abstract: Expandable, rubber-modified styrene polymers for elastic polystyrene foams comprisea) a continuous phase comprising polystyrene or a styrene copolymer containing at most 50% of copolymerized comonomers andb) from 5 to 30% by weight of a butadiene-styrene block copolymer dispersed therein,and also a low-boiling blowing agent. The rubber particles have a compact lamellar structure without polystyrene inclusions. The expandable styrene polymers are prepared by polymerization of styrene in the presence of the block copolymer and impregnation with the blowing agent.