摘要:
Process for preparing homopolymers of α-methylstyrene, or copolymers of α-methylstyrene and comonomers, by anionic polymerization in the presence of an initiator composition, which comprises using an initiator composition in which potassium hydride and at least one organylaluminum compound are present.
摘要:
The invention relates to an anionically polymerised, impact-resistant polystyrene with a dispersed plasticiser phase, comprising particles with capsule particle morphology and method for production thereof.
摘要:
In a process for the anionic polymerization of vinylaromatic monomers or dienes in the presence of a lithium organyl or lithium alcoholate and a magnesium and/or an aluminum compound, a sterically hindered phenol or amine is added.
摘要:
A process prepares impact-modified thermoplastic molding compositions which comprise a soft phase made from a rubber dispersed in a hard matrix composed of vinylaromatic monomers, where the hard matrix is prepared by anionic polymerization in the presence of a metal alkyl compound or a metal aryl compound of an element of the second or third main group, or of the second subgroup, of the Periodic Table.
摘要:
A process for the continuous anionic polymerization or copolymerization of styrene or diene monomers using an alkali metal alkyl compound as polymerization initiator is carried out in the presence of an alkyl- or arylmetal compound of an element which occurs in at least divalent form as rate regulator, preferably under non-isothermal conditions and without back-mixing in a tubular or tube-bundle reactor, preferably using an alkyl- or arylmetal compound A of the formula R1M1 and an alkyl- or arylmetal compound B of the formula R2nM2 in a molar ratio between B and A of from 0.1:1 to 500:1, where M1 is Li, Na or K; R1 is hydrogen, C1-C20-alkyl, C6-C20-aryl, or C7-C20-alkyl-substituted aryl; M2 is an n-valent element from group 2a, 2b or 3a of the Periodic Table; and R2 is hydrogen, halogen, C1-C20-alkyl or C6-C20-aryl; and a special anionic polymerization initiator containing no Lewis base.
摘要:
Water-insoluble polymers are prepared by free radical polymerization of ethylenically unsaturated monomers by a process in which the polymerization is carried out in an aqueous gel phase having a viscosity of at least 800 mPa.s and the gel former has a molecular weight of more than 20,000. The dispersions obtained have a long shelf life and the polymer can be readily precipitated.
摘要:
The present invention relates to a method for passivating metallic surfaces, wherein the metal surface is contacted with an aqueous composition comprising at least one water-soluble polymer (X) comprising acidic groups and with at least one polyamine (P), the pH of the composition being in the range from 0.5 to 2.
摘要:
The present invention relates to hollow bodies with improved barrier action, where the hollow bodies are composed of a three-layer sandwich structure with a shell made of polystyrene and with a middle layer as vapor barrier.
摘要:
The invention relates to a process for continuously preparing styrene polymers by anionic spray polymerization, which comprises i) styrene and the initiator solution being mixed in a dynamic or static mixer and then the mixture being sprayed, ii) the resultant droplets passing from the liquid monomer state to the melted polymer state during their free fall in the spraying tower, iii) the melt droplets being collected as a melt at the foot of the tower, the melt having a monomer content of below 1%, preferably below 0.1% (
摘要:
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.