Mechanical Dispersions and Transition Phenomena in Semicrystalline Polymers

Abstract

The existing data of mechanical dispersions in seven semicrystalline polymers (polyethylene, polypropylene, polyethylene terephthalate, polytrifluoromonochioro ethylene, polyamide, polyurethane and polytetra-fluoroethylene) are compiled and the frequency dependence of loss peak temperature (“transition map”) is illustrated. The primary and secondary dispersions occurring in the amorphous regions are identified on the basis of these results. The correspondence of the mechanical dispersions to dielectric ones, transition temperatures found in dilatometric measurements and change in NMR line width with temperature is discussed for these polymers.