Between Phenylene Sulfide - Phenylene Sulfide Synthesis And Properties Of Copolymer

Poly(1,4-phenylene sulfide)(PPS) is one of the best important resin of poly arylene sulfide (PAS), which is widely used in many areas for its outstanding heat resistance, high mechanical strength, excellent chemical resistance, good electronic properties and radiation resistance. As the modified material in the structure of PPS, Poly (metaphenylene sulfide-paraphenylene sulfide) copolymer (m-p-PPS) offsets the disadvantages such as poor toughness, great brittleness and indiscerptibility owing to some levels of meta-phenylene contents.In this paper, the synthesis of serial m-p-PPS copolymers containing different meta-phenylene units was studied by sodium sulfide method at atmospheric pressure. The optimum solvent, the ratio of raw material, the time and temperature of reaction were selected by experiment. The chain, aggregative structure and the molecular weight of copolymers were characterized by IR spectrum, X-ray diffraction (XRD) spectrum and gel permeation chromatography (GPC), respectively, and the results of experiments indicated that the copolymers were linear and partial crystalline. The crystalline ability and molecular weight decreased with the increase of meta-phenylene content.The thermal stability of m-p-PPS was studied by differential scanning calorimeter (DSC) and Thermo-gravimetric analysis (TGA). The results showed that the glass transition temperature (T_g), melting temperature (T_m) and thermal stability of the copolymers decreased with the increase of meta-phenylene content. The thermal decomposition kinetics, the isothermal and nonisothermal melt-crystallization kinetics analyses of m-p-PPS-10 were investigated by TGA and DSC separately, and the activation energies of thermal decomposition and melt-crystallization were obtained separately, and the thermal decomposition dynamic model and the melt-crystallization kinetic parameter were also gained.Finally, the solubility parameters of m-p-PPS were estimated by the Small method, and the solubility properties of m-p-PPS in some single solvent and mixed solvents were investigated. The results showed that the solubility parameters decreased and the solubility properties enhanced with the increase of meta-phenylene content.With the increase of meta-phenylene content, the T_g, T_m, molecular weight, crystallization and thermal stability of m-p-PPS decreased, but the solubility enhanced. The copolymers are hopeful to be applied in film and fiber.