The glass transition temperature of poly(phenylene sulfide) with various crystallinities

Abstract The glass transition temperature ( T g ) of poly(phenylene sulfide) (PPS) with various crystalline fractions has been studied using dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC). The DSC measurements show that T g can be observed from the heating curves for the PPS sample with very low crystallinity, and no T g is observed when the crystallinity is over 8%. DMA indicates that crystallinity has an important effect on molecular chain segment motion of PPS. When the crystallinity, X c , of PPS is over 38%, there is only one chain segment motion, which mainly results from the crystalline chain vibration; while three different chain segment motions occur for PPS samples with lower crystallinity ( X c < 26%), which are amorphous chain segment motion, crystalline chain segment motion and constrained amorphous chain segment motion. T g of PPS is mainly caused by the amorphous chain segment motion which is independent of the crystallinity, while the relaxation temperature corresponding to crystalline chain motion shifts to lower temperature as the crystallinity increases. The reduction of the relaxation temperature can be attributed to the disorder‐order transition of amorphous chains for PPS with lower crystallinity. © 2012 Society of Chemical Industry