Abstract A practical method for identification of defects that occur occasionally during the production of biaxial oriented polypropylene (BOPP) films is developed. The size and morphology of the defects in the BOPP film were observed with optical microscopy, and micro Fourier transform infrared (Micro-FTIR) and Raman spectroscopies were employed to identify the chemical composition of the defects. Significant amounts of ethylene and propylene units were found in the defects, and characteristic vibrational bands for crystalline PP were observed by both IR and Raman. However, one defect exhibited IR characteristics for ordered PE whereas the other showed amorphous PE structure. These results indicate that the defects are composed of either ethylene-propylene block copolymers with long sequences of both propylene and ethylene that can form ordered structures, or ethylene-propylene segmented copolymers with long propylene sequences that can crystallize and shorter ethylene sequences that are amorphous. Possible sources of these foreign materials and corresponding mitigation measures were discussed.

中文翻译：

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用微傅立叶变换红外光谱和拉曼光谱分析双轴取向聚丙烯薄膜的缺陷

摘要 开发了一种用于识别双轴拉伸聚丙烯 (BOPP) 薄膜生产过程中偶尔出现的缺陷的实用方法。用光学显微镜观察BOPP薄膜缺陷的大小和形貌，并采用微傅里叶变换红外（Micro-FTIR）和拉曼光谱来鉴定缺陷的化学成分。在缺陷中发现了大量的乙烯和丙烯单元，并且通过红外和拉曼观察到结晶 PP 的特征振动带。然而，一个缺陷表现出有序 PE 的 IR 特性，而另一个则表现出无定形 PE 结构。这些结果表明缺陷由具有可形成有序结构的丙烯和乙烯的长序列的乙烯-丙烯嵌段共聚物或具有可结晶的长丙烯序列和无定形的较短乙烯序列的乙烯-丙烯嵌段共聚物组成。讨论了这些异物的可能来源和相应的缓解措施。