MECHANICAL RELAXATION AND STRUCTURE OF PARTLY CRYSTALLINE POLYMERS

The relaxation behaviour of a partially crystalline high polymer solid, as measured by dynamic mechanical, dielectric and NMR methods, not only depends upon the chemical structure but also upon morphology. The investigation of these relations is very complicated, because the knowledge of a great number of morphological structure parameters is required. Recent dynamic mechanical and NMR investigations answer some basic questions arising for linear polyethylene, Especially the techniques of selective chemical variation of the non-crystalline regions by crosslinking, swelling and chlorination in the solid state and the crystallization under high pressure are used. The glass temperature of the non-crystalline regions and the fine-structure of the α- and γ-relaxations in single crystals and melt crystallized polyethylene are discussed. © 1969 Dr. Dietrich Steinkopff Verlag.