THERMAL CHARACTERIZATION AND CRYSTALLIZATION OF NOVEL POLY(ARYLENE ETHER ETHER SULFIDE)S

Thermal characterization has been carried out on a series of biphenol- and hydroquinone-based novel poly(arylene ether ether sulfide) polyme rs. Thermogravimetric analyses of the sulfide systems indicate high th ermal stability in air as well as in nitrogen. X-ray studies showed th e poly(ether ether sulfoxide) precursor materials to be amorphous and the poly(ether ether sulfide) materials to be semicrystalline. Based o n the number-average molecular weight of the poly(ether ether sulfoxid e) materials, and the glass transition temperatures determined by diff erential scanning calorimetry (d.s.c.), the limiting T-g infinity has been determined for both amorphous precursors. The biphenol-based prec ursor sulfoxide had a T-g infinity of 214 degrees C and the hydroquino ne-based precursor had a T-g infinity of 179 degrees C. D.s.c. studies showed the biphenol-based poly(ether ether sulfide) to have a T-g of 142 degrees C and T-m of 347 degrees C, and the hydroquinone-based pol y(ether ether sulfide) to have a T-g of 100 degrees C and a T-m of 243 degrees C. The equilibrium melting temperature T-m degrees has been d etermined for both sulfide polymers using the Hoffman-Weeks method. Th e hydroquinone-based poly(ether ether sulfide) exhibited a T-m degrees of 278 degrees C, and the biphenol-based poly(ether ether sulfide) sh owed a T-m degrees of 371 degrees C. The effect of time and temperatur e in the melt on the subsequent crystallization behaviour of the two s ulfide materials has also been investigated as a function of molecular weight.