Abstract: Sterically hindered phosphoramidates such as N,N′-bis[di-(2,6-xylenoxy)phosphinyl]piperazine are prepared by the reaction of a sterically hindered diaryl chlorophosphate, such as di-(2,6-xylyl) chlorophosphate, with a basic nitrogen compound containing at least two basic N—H groups, preferably a heterocyclic compound such as piperazine, in a predominantly liquid, solvent-free reaction mixture. The reaction may be conducted in the melt or in the presence of a non-solvent carrier, typically an aliphatic hydrocarbon. An excess of the basic nitrogen compound is employed as an acid acceptor.

Abstract: Reinforced thermoplastic compositions are provided comprising a high molecular weight linear polyester, such as poly(1,4-butylene terephthalate) in combination with a reinforcing agent and a minor proportion of an alkylhydroxyphenylalkanoyl-hydrazine, such as N,N'-bis(3,5-di-tert-butyl-4-hydroxy-hydrocinnamoyl)-hydrazine. The use of the alkylhydroxyphenylalkanoyl-hydrazine retains the inherent resistance to high voltage breakdown of the polyester resin component while not affecting the other properties of the composition, such as strength, modulus, shrinkage, etc.