期刊
POLYMER DEGRADATION AND STABILITY
卷 98, 期 6, 页码 1144-1149出版社
ELSEVIER SCI LTD
DOI: 10.1016/j.polymdegradstab.2013.03.017
关键词
Isotactic polypropylene; DSC; Natural aging; Photodegradation; Crystallinity; Thickness
The course of degradation in natural environment of polypropylene items was studied with DSC and thermogravimetric techniques. The enthalpic patterns of the materials vary with time of exposure. Measurements of the melting enthalpies in comparison with the heats of crystallization enabled to assess the evolution of crystallinity during exposure of plates and films of iPP. The induction time before the photochemical attack is of 800 h regardless of the thickness. The plates lose all practical mechanical properties after 4800 h of exposure, the film only after 2000 h. At the end of exposure, the plate provides a brittle and cracked material that includes a volatile phase and a heat resistant share due to crosslinking reactions. Some hypotheses on the degradation mechanism are presented. (C) 2013 Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据