New Indoor Accelerated Weathering Condition for Approximating Molecular Weight Distribution of Outdoor-Exposed LDPE  

作　　者：Takashl Miwa Yukitoshi Takeshita Yuichi Akage Masamitsu Watanabe Masaaki Takaya Takashi Sawada 

机构地区：[1]NTT Device Technology Labs, NTT Corporation 3-1, Morinosato-Wakamiya Atsugi-shi, Kanagawa 2430198, Japan [2]Technical Assistance and Support Center, NIT East Corporation 1-2-5, kamata-honcho, Ota-ku, Tokyo 1440053, Japan

出　　处：《Journal of Chemistry and Chemical Engineering》2015年第8期481-493,共13页化学与化工（英文版）

摘　　要：LDPE （low-density polyethylene） photo degraded through various accelerated weathering tests has the molecular weight distribution curves unlike that through outdoor exposure. The authors therefore developed new weathering test condition based on the existing accelerated weathering test using a xenon arc lamp. Samples of LDPE were photo degraded using various accelerated weathering test conditions and outdoor exposure. The physical properties and chemical structures of the photo degraded samples were studied through a tensile test, infrared spectroscopy, and gel chromatography. The authors found that the molecular weight distribution curve of a sample photo degraded using a xenon lamp at a higher BPT （black panel temperature） （73 ~C） was more similar to that of an outdoor-exposed sample than that of a sample photo degraded at the standard BPT （63 ~C）. It is considered that higher temperature accelerates radical recombination, consequently recreating molecular enlargement similar to the outdoor-exposed sample. Multiple regression analysis using newly introduced Mp （peak-top molecular weight） and Mw （weight-average molecular weight） as explanatory variables was conducted, which successfully enabled the authors to provide a simple explanation for the decrease in polymer tensile strength.

关 键 词：LDPE photo degradation molecular weight distribution accelerated weathering test outdoor exposure molecular enlargement. 

分 类 号：O631.61[理学—高分子化学] TQ560.7[理学—化学]