Societa' Italiana Resine S.i.r. S.p.a.

Mario Ermoni

Pierino Radici

Paolo Colombo

Sergio Custro

The thermal and chemical stability of etherified acetal homopolymers is improved by heat-treating the latter in the molten state at a temperature of at least 180.degree. C., in the presence of a halide of an alkali or alkaline earth metal, until substantially complete degradation of the unstable polyoxymethylene chains.

Process for improving the stability of etherified acetal homopolymers

An etherified acetal homopolymer is stabilized by heat-treating said homopolymer suspended in a liquid diluent chosen from water or mixtures thereof with polar organic compounds, preferably in the presence of a basic compound, at a temperature of 100.degree.-160.degree. C and below the melting point of the homopolymer, thereby to substantially degrade the unstable fraction of said homopolymer.

Growing community of inventors

Gorla Minore, Italy

Mario Ermoni