PERCENTAGE OF RIGID CHAIN-LENGTH, A NEW CONCEPT FOR PREDICTING GLASS-TRANSITION TEMPERATURES AND MELTING-POINTS OF POLY(ARYL ETHER KETONE)S AND POLY(ARYL ETHER SULFONE)S

Molecular design, microstructure, and physical properties of polymers are strongly related to each other. A better understanding of their interdependence will give the polymer chemist useful ideas for the synthesis of new macromolecules. The present paper aims to compare the thermal behavior of aryl polycondensates based on ether, sulfone, and ketone links. Ultimately the objective is to design a new polymer combining, for example, the glass transition (T(g)) of poly(ether sulfone)s and the crystallinity of poly(ether ether ketone)s. By the use of a new concept the percentage of rigid chain length, it is demonstrated that one can predict T(g) and T(m) of poly(aryl ether ketone)s and T(g) of poly(aryl ether sulfone)s. The feasibility of crystalline poly(aryl ether sulfone)s is also discussed on the basis of the same principle.