Abstract: Polyalkylene terephthalates which contain a fluorinated polyolefin in addition to a polymer having a glass transition temperature of less than -30.degree. C., are very tough, exhibit good stability to thermal shaping and hardness, and have a high modulus of elasticity and improved stress/strain behavior.

Abstract: A polycarbonate film having improved flame resistance and good stress-corrosion-cracking resistance is prepared from a solution of a mixture of a low molecular weight polycarbonate containing at least about 5% by weight halogen and a higher molecular weight polycarbonate prepared from bisphenol containing at least 90 mol percent bisphenol A. The novel film can be used to advantage for self-supporting electrical insulating films.

Abstract: Terephthalic copolyesters, the diol component of which mainly consists of ethylene glycol units, crystallize more rapidly than pure polyethylene terephthalate and can be moulded in a way comparable to polybutylene terephthalate.

Abstract: A branched, high molecular-weight polyaryl-ether sulphone which is the reaction product of approximately equimolar amounts of an aromatic dialkali metal bishydroxylate and a bis-(halogen-aryl) compound, whose aryl nuclei are linked by sulphonyl groups, and about 0.01 to about 2 mol %, based on the bishydroxylate or bis-(4-halogenaryl) compound, of an aromatic compound having at least three aromatically linked alkali metal hydroxylate substitutents and/or of a halogenaryl compound having at least three aryl-linked halogen substituents and which is capable of substitution under the reaction conditions of polyaryl-ether sulphone manufacture.