摘要:
Linear, thermoplastic, elastomneric copolymers of carbon monoxide and olefinically unsaturated compounds have an alternating sequence of repeating units and an average molecular weight Mw of the copolymers of from 80,000 to 1,200,000, binary, linear, alternating carbon monoxide/ethylene copolymers being excluded.
摘要:
The invention relates to the production of homopolymers, co-copolymers or block copolymers from cycloolefinic monomer units characterized in that polymerization occurs in the presence of a catalyst of general formula (I), and optionally in the presence of an additive, wherein the substituents and indices have the following meaning: M is a metal from group VIII B of the periodic table of elements; E1, E2 are independently from each other an element from group V A of the periodic table of elements; Z is a bridging structural unit; Ar stands for annelated aryl units independent of each other; L1, L2 stands for formally uncharged Lewis base ligands; X means monovalent or bivalent anions; k means 1 or 2; l, m, n represent 1 or 2, whereby m×n=1.
摘要:
Linear, thermoplastic, elastomeric copolymers comprise carbon monoxide and at least one olefinic C7- to C20-monomer and have an average molecular weight Mw greater than 15,000 g/mol and a Tg-value of less than −20° C., and comprise carbon monoxide, at least one olefinic C2- to C4-monomer and at least one olefinic C6- to C20-monomer and have an average molecular weight Mw greater than 40,000 g/mol and a Tg-value of less than 20° C.
摘要:
Linear, alternating .alpha.-olefin-CO copolymers are obtainable by polymerization of a monomer mixture comprisinga) carbon monoxide,b) 1-alkenes which are functionalized by a covalently bonded crown ether unit or cryptand unit A containing at least 5 heteroatoms selected from the group consisting of nitrogen, oxygen, sulfur and/or selenium in the polyheteroatom framework, and, if desired,c) C.sub.2 -C.sub.24 -1-alkenes.
摘要:
A process for preparing indene derivatives of the general formula I ##STR1## where R.sup.1 is a C.sub.1 -C.sub.10 -alkyl radical, a phenyl radical or a C.sub.1 -C.sub.4 -alkyl-substituted phenyl radical andA is a bridge which, together with the adjacent carbons, forms a six-membered aromatic or a five- or six-membered heteroaromatic or carbocyclic ring onto which a further aromatic ring may be fused,comprises reacting II with III ##STR2## (X=chlorine, bromine, iodine) in the presence of a Friedel-Crafts catalyst to give IV ##STR3## which is then dehydrogenated to I.
摘要:
Disclosed are novel liquid-crystal compounds, processes and intermediates for the preparation thereof, the use thereof for optical, electro-optical and electronic purposes, in particular in liquid-crystal (LC) media and LC displays, and to LC media and LC displays containing the same.
摘要:
The invention relates to a matrix liquid crystal display containing integrated non-linear elements and a liquid crystal mixture which has a particularly high resistivity.
摘要:
Lactones are prepared by catalytic carbonylation of oxiranes using a catalyst system comprising a) at least one cobalt compound as component A and b) at least one metal compound of the formula (I) as component B, MXxRn-x (I) where M is an alkaline earth metal or a metal of group 3, 4 or preferably 12 or 13 of the Periodic Table of the Elements, R is hydrogen or a hydrocarbon radical which may be substituted on the carbon atoms other than the carbon atom bound to M, X is an anion, n is a number corresponding to the valence of M and x is in the range from 0 to n, with n and x being selected so that the compound is uncharged, as catalyst.
摘要:
The invention relates to a catalytical process for preparing poly(3-hydroxyalkanoates) by copolymerizing an oxirane compound with carbon monoxide in the presence of a) at least one single- or multicenter neutral transition metal complex (A) based on a metal of groups 5 to 11 of the Periodic Table of the Elements, in which the metal center(s) is/are present in the formal oxidation state 0, and/or b) at least one single- or multicenter anionic transition metal complex (B) based on a metal of groups 5 to 11 of the Periodic Table of the Elements, where multicenter transition metal complexes have metal centers which, without exception, are of the same transition metal, which comprises carrying out the copolymerization in the presence of at least one nucleophile other than hydroxy-substituted pyridine compounds.