BETA-RELAXATIONS IN SEMICRYSTALLINE POLY(ARYL ETHER ETHER KETONE) FILMS - MECHANICAL COUPLING AND INTERACTIONS BETWEEN PHASES

Mechanical spectrometry was performed on poly(aryl ether ether ketone) (PEEK) polymer films in order to evaluate the influence of a crystall ine phase on the beta-relaxation. The Halpin-Kardos model has been app lied to describe the beta dynamic mechanical behavior of semicrystalli ne PEEK films considered as composite materials. Changes in the low-te mperature component of the beta-relaxation induced by the crystalline phase are discussed in terms of mechanical coupling between phases. Mo reover, it is found that the pattern of the higher temperature compone nt of the beta transition is governed, in addition, by the rigid amorp hous phase.