Abstract
An experimental study was carried out on the photodecomposition of unplasticized and plasticized PVC films. The PVC films were irradiated with a Xenon lamp in the temperature range of 30-50°C. The amount of hydrogen chloride evolved was determined by a chlorine ion-meter. Other gaseous products of the photodecomposition were identified and determined by gas-chromatography. The summary of the results obtained are as follows.
(1) Eleven kinds of gaseous products were detected during the photodecomposition of unplasticized PVC film. The main products were hydrogen chloride and carbon dioxide, and their amounts were of the order of 40-60μg/cm2. Hydrogen chloride evolved increased with an increase in temperature, while carbon dioxide decreased.
(2) In the case of photodecomposition of PVC film plasticized with Di-2-ethylhexyl phthalate, fifteen kinds of gaseous products were detected. The amount of hydrogen chloride evolved was 1/10-1/7 of that of unplasticized film. Carbon dioxide evolved increased with an increase in temperature. This fact was supposed to be due to the photodecomposition of Di-2-ethylhexyl phthalate. The amounts of olefinic hydrocarbons (ethylene, propylene) were about several tens times that in the case of unplasticized film.
