CHANGE IN THE THERMOPHYSICAL PROPERTIES OF POLYMERIC MATERIALS SUBJECTED TO GAMMA-IRRADIATION. 1. RESULTS OF MEASURING THE SPECIFIC HEAT OF CERTAIN POLYMERS DURING AND AFTER GAMMA-IRRADIATION

摘要

The application of thermophysical methods to the investigation of polymers subjected to ionising radiations can provide valuable information on the structural transformations occurring in them, and makes it possible to characterise quantitatively the parameters of radiation chemical processes. This reported research is the first in a proposed series of papers devoted to the analysis of the changes in the thermophysical properties of polymers subjected to gamma radiation of relatively low intensity. A comparison of the specific heats of a series of industrial specimens of polymers during and after irradiation is made. LDPE, PMMA, PTFE, EPDM, butadiene-acrylonitrile rubber and fluorine-containing rubber were tested. The considerable differences between the true specific heat of the polymers and the 'effective' specific heat measured in the course of irradiation and in post-effect conditions, made it possible to obtain information on the characteristics of the radiation chemical processes occurring in them. 17 refs. (Article translated from Plasticheskie Massy, No.11, 2005, p.24-7)