ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

The degradation of polycarbonates

B. M. Kovaraskaya

Sci-Res. Inst., Plastics, Moscow.

Abstract: Changes in the structure during pyrolysis of polycarbonates from bisphenol A were studied. Gaseous pyrolysis products were analyzed by chromatography, the solid residue by infrared spectroscopy, and the mol. movement by nuclear magnetic resonance. During thermal degradation at high temps., the Me groups are torn off with the formation of CH₄, the ether bonds are pulled apart with the formation of C oxides, which results in firming up the structure with an increase in Ph nuclei. The thermoxidative degradation is an autocatalytic chain reaction with a degenerative branching. The effective activation energy of the oxidn. is 36.5 kcal./mole. In reworking by molding, the degradation of polycarbonates takes place much faster than by thermoxidative degradation. The conditions of temp. and time for optimum reworking with min. degradation are discussed.

Full paper in Portable Document Format: 181a13.pdf (in Slovak)

Chemical Papers 18 (1) 13–20 (1964)