Kinetic Aspects of Aging of Poly(vinyl Chloride)-Based Polymer Materials

The results of the complex study of samples of plasticized poly(vinyl chloride) (PVC) subjected to aging under model and climatic conditions or being in use for a long time (from 15 to 30 years at 253–301 K) studied by various techniques and the mechanism of their aging are presented in the article. Using the thermogravimetric, chromatographic, ultraviolet and infrared spectroscopic techniques, gel permeation chromatography, mercury porosimetry, and techniques for measuring mechanical strength properties of the materials (e.g., tensile strength and strain), we have shown that the service and functional properties of plasticized PVC were lost as a result of diffusion-controlled desorption of a plasticizer or other additives. Information about the aging conditions can be derived from the experimental time histories of the weight loss or additive depletion in the course of functioning of PVC samples or their exposure to different impacts. These experimental data are used to formulate a mathematical description of the aging process in these systems and to predict the lifetime of such materials in use. The experimental part of the article is preceded with the literature review conveying the authors' point of view on the processes going on in PVC materials by aging under the action of natural and artificial conditions.