摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
In a process for polymerizing dienes in a solvent comprising vinylaromatic monomers, the polymerization is carried out in the presence of a metal compound of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo or W as catalyst and a Lewis acid as cocatalyst and, if desired, an alkylating agent and, if desired, a regulator. This process can be used for preparing high-impact polystyrene, acrylonitrile-butadiene-styrene copolymers or methyl methacrylate-butadiene-styrene copolymers.
摘要:
The present invention relates to thermoplastic molding compositions comprising a mixture of (A) from 30 to 69% by weight, based on the sum of components (A), (B) and (C), of a methyl methacrylate polymer, (B) from 30 to 69% by weight, based on the sum of components (A), (B) and (C), of a copolymer obtainable by polymerizing a styrenic monomer and a vinyl cyanide, and (C) from 1 to 40% by weight, based on the sum of components (A), (B) and (C), of a graft copolymer obtainable from (C1) from 60 to 90% by weight, based on (C), of a core obtainable by polymerizing a 1,3-diene and a styrenic monomer, (C2) from 5 to 20% by weight, based on (C), of a first graft shell, and (C3) from 5 to 20% by weight, based on (C), of a second graft shell composed of an alkyl (meth)acrylate polymer, with the proviso that the ratio of (C2) to (C3) is in the range from 2:1 to 1:2.
摘要:
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.
摘要翻译:均聚物,共聚物或嵌段共聚物通过丙烯酸酯和/或甲基丙烯酸酯在引发剂组合物的存在下的阴离子聚合制备,所述引发剂组合物包含A)有机碱金属化合物,B)有机铝化合物和C)与碱金属形成络合物的添加剂 并且选自具有至少两个醚氧原子的开链醚,大环醚和cryptands,或者由通式I的季铵阳离子组成的组,其中A是N,P,As或Sb和R a, R b,R c和R d彼此独立地为各自为未取代或取代的烷基,环烷基,芳烷基或芳基,其中两个相邻的基团与杂原子A一起可以形成可含有一个的5或6元杂环结构 或另外两个选自氮,氧和硫原子的杂原子。