Hanjian,Zhao Yaqiong, Wang Yanxiao, Yan Chenguang, Wang Yimai, Liu Chuntai

1. The results indicate that there indeed exists a synergistic effect between photo-oxidative degradation and the ESC behavior for PC specimens. • The stress relaxation test is a better way to evaluate the synergistic effect between photo-oxidative degradation and the ESC behavior of PC injection molded parts. Abstract Conclusions By the ESC tests and morphology observation, The results indicate that there is a synergistic effect between photo-oxidative degradation and environmental stress cracking for PC injection molded parts. And reveal that stress relaxation test is a better way to evaluate this effect. References • Sudesh S Fernando, Paul A, Polym Degrad Stab 94, 87 (2009). • Nagai N, Okumura H, Imai T,Polym Degrad Stab, 81,495(2003). • Jennifer M Hoffman, Angele Sjong, SPE ANTEC PROCEDINGS, 1412 (2006). • A R Sousa, Polym Degrad Stab, 92, 1475 (2007). Experimental • Photo-Oxidative Degradation Testing Half ofthe specimens were irradiated for 168 hours continuously at 50±2°C in an ultraviolet(UV) weatherable chamber. • ESC Testing Thestress relaxation test and tensile stress-strain test were carried out in the ethanol environment. • Sample Preparation (a) (b) (a) (b) The significant yellowing after a 168 hours UV irradiation Tg of undegraded and degraded specimens Tensile stress-strain curves of PC specimens under different test conditions The surface cracking of PC specimens after tensile stress-strain in the ethanol environment (a)Undegraded specimens and(b)degraded specimens Stress relaxation curves of PC specimens under different test conditions (c) (d) The surface cracking of PC specimens after stress relaxation in the ethanol environment (a,b)Undegraded specimens and(c,d)degraded specimens Effect of Photo-Oxidative Degradation on Environment Stress Cracking Behavior of Polycarbonate Injection Molded Parts Hanjian,Zhao Yaqiong, Wang Yanxiao, Yan Chenguang, Wang Yimai, Liu Chuntai National Engineering Research Center for Advance Polymer Processing Technology,Zhengzhou University, 97 Wenhua Road, Zhengzhou, Henan, P. R. China • The photo-oxidative degradation and environmental stress cracking of plastic tend to occur simultaneously due to the complexity of the actual service environ-ment.This paper discusses the effect of photo-oxidative degradation on the ESC behavior of PC injection molded products, depending on the failure behavior and performance changes of undegraded and degraded plastics under the action of chemical solvents. Introduction Photo-oxidative degradation of plastics ESC of PC injection molded parts Results and Discussion • Photodegradation of Polycarbonate • ESC behavior of PC specimens • Stress Relaxation Behavior Tensile Stress-strain Behavior