Vapor Pressure of Plastic Materials

A method is presented of measuring the equivalent nitrogen vapor pressure of polymeric materials over a range of temperatures. It is found that, for the range of temperatures investigated (300–450°K), the vapor pressure‐temperature characteristics of the polymeric materials studied are described by the empirical relation $$\log \mathrm{P=A-B/T}$$ . The values of the constants A and B in this equation are determined for a number of materials including nylon, Teflon, saran, polyethylene, and mylar.