Investigation of the mechanism of the thermal carbonization of chlorine-containing carbon-chain polymers

Abstract

1. Polyvinyl chloride (PVC) differs from polyvinylidene chloride (PVDC), the copolymer (CP), and chlorinated polyvinyl chloride (CPVC), in the presence of a second sharp maximum (450°) on the differential curve of the liberation of volatile substances, corresponding to transformation of the aromatic structure and the liberation of hydrogen. 2. The x-ray diffraction data show the formation of a condensed aromatic system at a comparatively low temperature of carbonization (250°) of PVC and a transformation at a temperature corresponding to the second maximum of the liberation of volatile substances (400°). No condensed aromatic system is formed in the carbonization of PVDC, up to 360°. 3. According to the data of infrared spectroscopy, at comparatively low temperatures of carbonization of PVC (225), a conjugated polyenic structure arises, which is transformed into a condensed aromatic system. During the carbonization of PVDC, chlorine-containing conjugated polyenic structure arise, containing triple and cumulative double bonds. 4. The generation of the structure of nongraphitized carbon for PVDC, CPVC, and CP occurs at the early stages of carbonization.