THE STABILIZATION OF PVC AGAINST HEAT AND LIGHT

Abstract — The lecture provides a survey on the actual status of the heat and light stabilization of PVC with special empha-sis on the mode of action of the stabilizers. In the first part a brief treatment of the most important facts of the ther-mal degradation of PVC are given, followed by a discussion of some proved specific functions of heat stabilizers by using organotin mercaptide as a typical example. A general concept differentiating preventive and curative stabilizer functions is proposed which seems to be applicable to all types of ther-mal stabilizers. The second part of the lecture deals with the problematics of light degradation and light stabilization. Some fundamental facts of the light degradation are briefly dealt with and provisions for an enhancement of the light sta-bility are discussed, covering also the implication of the thermal stabilizers. 1