Akzo N.v.

Doetze J Sikkema

Cornelius M Vrouenraets

Erwin W Erdhuisen

Carel T Wreesmann

Copolyamides are described comprising: (1) 0.22-0.28 mole fraction units derived from terephthalic acid; (2) 0.2-0.28 mole fraction units derived from paraphenylene diamine; (3) 0.22-0.28 mole fraction units derived from isophthalic acid; and (4) 0.22-0.28 mole fraction units derived from a 3,3'- or 4,4'-diamine of diphenyl methane, diphenylpropane-2,2, diphenyl cyclohexane-1,1, diphenyl ether, diphenyl sulfide, diphenyl sulphone, or benzophenone.

Aramid polymer from aromatic dicarboxylic acid mixture and aromatic

Polyurethanes having high hyperpolarizability densities and other favorable properties can be easily prepared from nonlinear optical active diols (NLO-diols) of a certain general formula, which have a delocalized .pi. electron system to which both an electron donor group and an electron acceptor group are coupled directly (D.pi.A system). The polyurethanes may be used in optical waveguides.

Non-linear optical active diols and polyurethanes prepared therefrom

A combination of 10-80% by volume of reinforcing fibres and 20-90% by volume of thermoplastic fibres or films suitable to be formed into a composite structure, the thermoplastic fibres or films essentially consisting of an amorphous copolyamide built up of units derived from at least two different dicarboxylic acids and at least two different diamines, of which the divalent aromatic radicals are linked together by amid bonds selected from the groups P1, P2, Q1 and Q2,

Composites comprising an aramid matrix

An amorphous, injection-moldable copolyamide comprising linear chains of each of the units having the formulae:

Amorphous aromatic copolyamide, a process for the preparation thereof,

Flexible layered product for use in waterproof garments or tents of a textile material covered with a waterproof material having a water vapor transmission rate of at least 1000 g/m.sup.2 day, the textile material being covered with a film of a copolyether ester consisting of a plurality of recurrent intralinear long-chain ester units and short-chain ester units which are randomly joined head-to-tail through ester bonds.

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An Ellecom, Netherlands

Doetze J Sikkema