UV Photodegradation of Polypropylene Thick Bars Containing Rutile-type TiO_2 Nanorods  

作　　者：Lin Qi Yan-fen Ding Quan-xiao Dong Bin Wen Peng Liu Feng Wang Shi-min Zhang 阳明书 

机构地区：[1]Beijing National Laboratory for Molecular Science,Key Laboratory of Engineering Plastics,Institute of Chemistry,Chinese Academy of Sciences [2]Beijing Engineering Research Center of Architectural Functional Macromolecular Materials,Beijing Building Construction Research Institute,Co.,Ltd.

出　　处：《Chinese Journal of Polymer Science》2014年第7期834-843,共10页高分子科学（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(No.51133009);the National Basic Research Program of China(No.2012CB720304);the "Strategic Priority Research Program" of the Chinese Academy of Sciences(No.XDA09030200)

摘　　要：Surface modified rutile-type titanium dioxide （CST） nanorods were used as a UV absorber in polypropylene （PP） thick bars in combination with the hindered amine light stabilizer （HALS） Chimassorb 944 （C944）. For all of the tested samples, the photodegradation was mainly limited in the region near the exposed surface, as proved by the carbonyl index and molecular weight. Compared with the typical HALS photostabilization system containing organic hindered phenol UV absorber Tinuvin~ 328 （T328）, the thickness of photodegradation region for PP/C944/CST was only a quarter to that for PP/C944 and PP/C944/T328, while the rates of reduction in molecular weight and increase in carbonyl index were much lower. Optical microscopic observation showed that the evolution of surface micro-cracks in PP/C944/CST was quite different from that in the other samples, while scanning electronic micrographs revealed that the depth of the micro-cracks in PP/C944/CST was much shorter than that in the others. It is therefore concluded that the protection of CST on PP thick bars is mainly attributed to the outstanding UV-shielding and cracks-blocking abilities.Surface modified rutile-type titanium dioxide （CST） nanorods were used as a UV absorber in polypropylene （PP） thick bars in combination with the hindered amine light stabilizer （HALS） Chimassorb 944 （C944）. For all of the tested samples, the photodegradation was mainly limited in the region near the exposed surface, as proved by the carbonyl index and molecular weight. Compared with the typical HALS photostabilization system containing organic hindered phenol UV absorber Tinuvin~ 328 （T328）, the thickness of photodegradation region for PP/C944/CST was only a quarter to that for PP/C944 and PP/C944/T328, while the rates of reduction in molecular weight and increase in carbonyl index were much lower. Optical microscopic observation showed that the evolution of surface micro-cracks in PP/C944/CST was quite different from that in the other samples, while scanning electronic micrographs revealed that the depth of the micro-cracks in PP/C944/CST was much shorter than that in the others. It is therefore concluded that the protection of CST on PP thick bars is mainly attributed to the outstanding UV-shielding and cracks-blocking abilities.

关 键 词：POLYPROPYLENE Titanium dioxide nanorods PHOTODEGRADATION Molecular weight Surface micro-cracks. 

分 类 号：O632.12[理学—高分子化学]