Investigations Of The Environmental Stability Of Polycarbonate

In this paper,the chemical environmental stress cracking resistance and temperature and humidity aging resistance of polycarbonate were investigated,which will reflect the environmental stability of polycarbonate in practical application.The experimental results of the chemical environmental stress cracking resistance of polycarbonate indicate that the stress fracture of polycarbonate is mainly composed of two processes,plasticizing process and crack expanding process.When polycarbonate contacts with the mixed solution,the weak polycarbonate dissolution by toluene causes the rapid plasticization of polycarbonate.And at the same time,the isopropanol with high polarity causes the material to begin to crack.Plasticized polycarbonate will accelerate the expansion of crack.When more and more cracks grow and the erosion of the sample becomes deeper and deeper,the sample eventually breaks because it cannot bear the certain strain.The experimental results of temperature and humidity aging resistance of polycarbonate indicate that polycarbonate aging process is relatively slow at medium temperature(70?),and the properties of the material are almost not damaged.During this aging process,mainly side chains and end groups in polycarbonate are broken,and temperature has little effect on the aging of polycarbonate.At high temperature(95?),the aging rate of polycarbonate is significantly faster than that at 70? under dry conditions,but the aging degree is still relatively small and the performance changes were not obvious after 30 days.The aging rate of polycarbonate increased significantly under high humidity conditions,and the material has completely failed after only 14 days.