The Yielding of Polycarbonate in a Nitrogen Environment at Low Pressures and Temperatures.

摘要

There have been investigations on the effect of strain-rate and temperature on the stress-strain curve in various environments, but there have not been any quantitative experiments on the effect of pressure of the environmental gas. Isothermal measurements at low pressure are particularly interesting because the shear yield strength of the polymer remains essentially constant. On the other hand, the isobaric measurements as a function of temperature are more complicated since the shear yield point varies significantly with temperature. These measurements as a function of pressure are very important because theory indicates that the solubility is proportional to the pressure. In the investigation N2, Ar, and O2 environments were used with polycarbonate (PC), polymethylmethacrylate, and polychlorotrifluorethylene. The same general behavior was observed for all gas-polymer systems. Only the results of the N2-PC system will be presented. This is the first time that the stress-strain behavior of polymer has been quantitatively measured as a function of the partial pressure of a gaseous environment. (Author)