聚甲醛热降解性能研究  

Research on Polyoxymethylene Thermal Decomposition Property

作　　者：胡萍[1] 姜明[1] 汪巍[2] 陈猛[1] 吴愧[1] 

机构地区：[1]武汉理工大学化学工程学院,湖北武汉430070 [2]武汉大学化学与分子学院,湖北武汉430071

出　　处：《合成材料老化与应用》2005年第3期20-23,共4页Synthetic Materials Aging and Application

摘　　要：通过测定聚甲醛的熔融指数、拉伸强度及断裂伸长率,分析、比较其热老化的速度;同时应用扫描电镜、X-射线光电子能谱观察和分析了聚甲醛(POM)的表面形貌、表面官能团的类型。试验结果表明:120℃热老化试验条件下,随着老化时问的延长,熔融指数逐渐增大,说明发生了缓慢的热氧化降解过程;20天短期热老化对聚甲醛拉伸强度及断裂伸长率影响不是很明显,说明POM的热老化应该有一个相当长的过程;扫描电镜显示:105天热老化后,聚甲醛表面出现龟裂和粉化现象;X-射线光电子能谱显示:老化前后样品中Cls谱均含有C-C和C-O2个峰,但老化后C-C含量降低,C-O含量增加,说明POM的热老化以C-C断裂降解为主,原始试样Ols/Cls为56.98%,105天老化后为72.92%。The thermal ageing rate was analyzed and compared by testing melt index （MI） value, tensile strength and breaking extension ratio of POM, and the surface appearance and types of surface group Was analyzed and observed by SEM and XPS. The results show that at 120℃ as the ageing time last, the MI increased, which indicates slow thermal oxidational decomposition had happened; a short-period ageing of 20 days did not affect the tensile strength and breaking extension ratio apparently, which indicates the ageing of POM is quite a long process; SEM picture indicated there were alligator and efflorescence in surface of POM after 105-day ageing; XPS picture indicates there are two peaks C-C, C-O in spectra of specimens both before and after ageing; but after ageing the content of C-C decreased, C-O content increased, which shows the thermal ageing of POM is main chain rupture and decomposition of C-C. The O1s/C1s of original specimens was 56.98% , while was 72. 92% after the ageing of 105 days.

关 键 词：聚甲醛 表面 热降解 性能表征 

分 类 号：TQ326.51[化学工程—合成树脂塑料工业]