Infrared study of polypropylene

The structural configurations that distinguish the atactic phase from the isotactic phase give rise to infrared spectra characteristic of each phase. Since these differences are quite significant, a method is proposed with which the isotacticity can be determined. The relation between the isotactic phase and crystallinity is considered, and its application to this study is discussed. The formation of oxygen-containing degradation products was followed during accelerated oxidation and the products identified. There is also evidence that more numerous oxygen containing degradation products form in polypropylene than in polyethylene. The type of unsaturation was also determined, and its presence confirmed by chlorination.