Ethylene Incorporation in Polypropylene: . Effect On Thermal-Related Properties

Abstract

Polypropylene (PP) samples with ethylene randomly distributed at levels up to nine weight percent were analyzed. At these levels, there is no major indication of "blockiness" in the incorporation, i.e., the level is not high enough to deliteriously influence the effectiveness of chain disruption by the comonomer. The DSC melting point drops about 4.4 ° C for each percent of eth ylene incorporated. Similarly, the crystallization peak temperature drops about 3.6°C for each percent of ethylene incorporated. Finally, the glass transi tion temperature (T_g ) drops almost 2 ° C for each percent of ethylene.