The Effects of the Quantity and Placement of Copolymer Units Within the Polymeric Chain on the Crystallization Phenomena in Polymers.

摘要

The crystallization kinetics of random copolymers containing linear polyethylene as the major constituent and methyl and m-propyl side groups as counits have been studied by dilatometric techniques. Major attention has been given to the analysis of the temperature coefficient of the process which is demonstrated to be nucleation controlled. It is found that,irrespective of the mode of nucleation selected,there is a systematic increase in the crystallite interfacial free energy with increasing copolymeric content. The major increase occurs at copolymer compositions where spherulitic structures are no longer resolved. The values deduced for the interfacial free energy strongly favor the three-dimensional mode of nucleation. (Author)