کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5205025 | 1381980 | 2006 | 9 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: The combined effect of photodegradation and stress cracking in polystyrene The combined effect of photodegradation and stress cracking in polystyrene](/preview/png/5205025.png)
This work aims to analyze the effects of photodegradation on the stress cracking resistance of polystyrene. Injection moulded samples were exposed to the ultraviolet light for various times in the laboratory prior to solvent contact. The bars were then stressed in a tensile testing machine under the presence of butanol. During this period the stress relaxation was monitored and the ultimate properties were evaluated after selected periods of stress cracking. Complementary tests were done by size exclusion chromatography and by scanning electron microscopy. The results indicated that butanol causes significant modification in polystyrene, with extensive surface crazing as well as reduction in mechanical properties. This is intensified under higher mechanical stress. The previous degraded samples showed a higher level of stress relaxation and a greater loss in tensile strength in comparison to the undegraded ones. The synergist action of photodegradation and stress cracking in polystyrene may be a consequence of the chemical changes caused by oxidation like the formation of polar chemical groups and the reduction in molecular weight.
Journal: Polymer Degradation and Stability - Volume 91, Issue 7, July 2006, Pages 1504-1512