Abstract:
The invention relates to polymer-modified nanoparticles which are suitable as UV stabilisers in polymers, characterised in that they are obtainable by a process in which, in a step a), an inverse emulsion comprising one or more water-soluble precursors of the nanoparticles or a melt is prepared with the aid of a random copolymer of at least one monomer containing hydrophobic radicals and at least one monomer containing hydrophilic radicals, and, in a step b), particles are produced, and to the use thereof for UV protection in polymers.
Abstract:
A supported catalyst for olefin polymerization comprises A) as support material, a copolymer comprising the monomer units I, II and III, where the monomer units I have the formula (I) and the monomer units II have the formula (II), where the variables have the following meanings: R1 is hydrogen, C1-C4-alkyl or phenyl, R2 is substituted or unsubstituted aryl or branched or unbranched alkyl or alkenyl, A1 is a direct chemical bond or a substituted or unsubstituted phenylene group, R3 are identical or different and are each hydrogen, C1-C10-alkyl or substituted or unsubstituted phenyl, p is an integer from 0 to 8, and R4 to R7 are hydrogen, C1-C10-alkyl or substituted or unsubstituted phenyl, and the monomer units III have polar groups, and B) at least one metallocene complex and C) at least one compound capable of forming metallocenium ions. A process for preparing such supported catalysts, copolymers suitable as support material and a process for the polymerization of olefins in the presence of a catalyst according to the present invention are also provided.
Abstract:
A process for preparing a supported catalyst comprises the steps of (1) preparation of a copolymer having comonomer units which comprise leaving groups; (2) polymer-analogous reaction with a substituted or unsubstituted cyclopentadienyl compound, and (3) reaction of the copolymer of (2) with a mono-Cp-metallocene compound.
Abstract:
Processes for preparing polymers of vinylic monomers where polymerization is conducted in the presence of free-radical initiators and electron donors.
Abstract:
Polymeric tetraaroxyperylene-3,4,9,10-tetracarboxylic diimides of the formula I ##STR1## (R.sup.1 : denotes identical or different aryl radicals which may be substituted by cyano, nitro, halogen, C.sub.1 -C.sub.18 -alkoxy, C.sub.5 -C.sub.7 -cycloalkyl and/or C.sub.1 -C.sub.18 -alkyl and may each contain up to 24 carbon atoms; R.sup.2 : denotes C.sub.2 -C.sub.30 -alkylene groups whose carbon chain may be interrupted by from 1 to 10 oxygen atoms in ether function or by a phenylene or cyclohexylene group, or optionally C.sub.1 -C.sub.10 -alkylene- or oxygen-bridged C.sub.6 -C.sub.30 -arylene or cyclohexylene radicals; n: is from 2 to 100), preparation thereof and use thereof and also tetraaroxypery-lene-3,4,9,10-tetracarboxylic dianhydrides as intermediates therefor.
Abstract:
Copolymer-modified nanoparticles produced by a process in which nanoparticles are ablated by laser radiation from a surface of a substrate in a liquid include an amphiphilic copolymer.
Abstract:
A process for preparing polymers which comprises conducting polymerization in the presence of free radicals of the formula I where Q is NR2 or S and T is CR3R4 or S and R1, R2, R3 and R4 can be identical or different and independently are hydrogen, C1- to C20-alkyl or C6- to C18-aryl.
Abstract:
A process for preparing polymers of N-vinyl compounds comprises polymerizing the vinyl compounds in the presence of free radicals of the formula I where Q is NR2 or S and T is CR3R4 or S and R1, R2, R3 and R4 can be identical or different and are, independently of one another, hydrogen, C1-C20-alkyl or C6-C18-aryl.
Abstract:
The invention relates to the use of statistical copolymers containing at least one structural unit containing hydrophobic radicals and at least one structural unit containing hydrophilic radicals as emulsifiers, in particular in the synthesis of nanoparticles, and to processes for the production of such particles in which, in a step a), an inverse emulsion comprising one or more water-soluble precursors of the nanoparticies or a melt is prepared with the aid of a statistical copolymer of at least one monomer containing hydrophobic radicals and at least one monomer containing hydrophilic radicals, and, in a step b), particles are produced.
Abstract:
Copolymer-modified nanoparticles produced by a process in which nanoparticles are ablated by laser radiation from a surface of a substrate in a liquid include an amphiphilic copolymer.