Simultaneous Measurement of Glass-Transition Temperature and Crystallinity of As-Prepared Polymeric Films from Restitution

Abstract

The glass-transition temperature (T-g) and degree of crystallinity (x(C)) are important properties of polymers. However, for some polymers, current techniques have some difficulties in measuring T-g and X-c, particularly for as-prepared films without damage. Here, we develop a new technique to simultaneously determine T-g and X-c by measuring the restitution of a ball on an intact polymer film or sheet as a function of temperature. Demonstrating with eight different types of polymers, we show that T-g is the onset of the decrease in restitution, and X-c is the minimum restitution for semi-crystalline polymers with X-c up to 50%. Our simple yet versatile technique could provide a useful tool to measure challenging T-g and X-c of films and sheets by the conventional methods.