THERMAL STUDIES OF BLENDS OF POLY(PHENYLENE SULFIDE) (PPS) WITH POLY(PHENYLENE SULFIDE SULFONE) (PPSS) AND WITH POLY(PHENYLENE SULFIDE ETHER) (PPSE)

Abstract

The miscibilities of poly(phenylene sulfide/poly(phenylene sulfide sulfone) (PPS/PPSS) and poly(phenylene sulfide/poly(phenylene sulfide ether) (PPS/PPSE) blends were investigated in terms of shifts of glass transition temperatures T-g of pure PPS, PPSS, and PPSE. The crystallization kinetics of PPS/PPSS blends was also studied as a function of molar composition. The PPS/PPSS and PPS/PPSE blends are respectively partially and fully miscible. PPSE shows a plasticizing effect on PPS as does PPS on PPSS, which necessarily improves the processibility in the respective systems. We can control T-g and melting temperature T-m of PPS by varying amounts of PPSE in blends. The melt crystallization temperature T-mc of PPS/PPSE blends was higher than that of the PPSE homopolymer. Therefore, these blends require shorter cycle times in processing than pure PPSE. The overall rate of crystallization for PPS/PPSS blends follows the Avrami equation with an exponent similar or equal to 2. The maximal rate of crystallization for PPS/PPSS blends occurs at a temperature higher by 10 degrees C than that for PPS, while the crystallization half time t(1/2) is 4 times shorter. In the cold crystallization range, crystal growth rates increase and Avrami exponents decrease significantly as the temperature increases