Synthesis Of Hyperbranched Poly(Phenylene Sulfide) And Study On Linear/Hyperbranched Poly(Phenylene Sulfide) Blends

Hyperbranched polymers have attracted considerable and increasing interests during recent years because of their unique properties。Unlike dendrimers prepared by stepwise synthesis,hyperbranched polymers need a simple preparation process。Owing to the highly functionalized globular structures,hyperbranched polymers exhibit different properties from those of linear polymers of the same molar mass,such as lower entanglement degree,a large number of functional end groups,low viscosity in solution and in the molten state,etc。Hyperbranched polymers are often discussed as a more rapidly prepared and more economical replacement for perfect dendrimers in some applications processing aids for linear polymers,coating and composites modification。1,Synthesis and characterization of hyperbranched poly(phenylene sulfide)In this paper,a novel synthesis route for hyperbranched poly(phenylene sulfide)(HPPS)was presented。The hyperbranched poly(phenylene sulfide)was prepared by 2,4-dichlorlbenzenthiol as an AB₂ type monomer,KOH and KCO₃ was used catalysts,using NMP as the solvent by a one-step polymerization process。The effects of reaction time and reaction temperature on the polymerization behavior of HPPS were investigated。The HPPS were characterized。2,Thermal degradation of the hyperbranched poly(phenylene sulfide)An advanced heat-resistant hyperbranched poly(phenylene sulfide)(HPPS)had been subjected to dynamic thermogravimetric analysis(TGA)in nitrogen。The thermal decomposition kinetics had been analyzed by applying the Kissinger,Friedman and Ozawa-Flynn methods。The Coats-Redfern method was used to discuss the probable degradation mechanisms。The solid-state decomposition mechanism followed by the degradation stage of HPPS was Phase boundary controlled mechanism(R1)。The thermal degradation was a random chain scission process。3,Non-isothermal crystallization behaviour of PPS/HPPS blendsThe non-isothermal crystallization behaviour of poly(phenylene sulfide)(PPS)in blends with hyperbranched polu(phenylene sulfide) (HPPS)was studied by means of differential scanning calorimetry(DSC)。It was observed that the PPS crystallization temperature was found to decrease upon addition of the HPPS。The Ozawa equation is valid not only for the neat PPS,but also for the blends。It has been concluded that the crystallization of the PPS was hampered by content of hyperbranched poly(phenylene sulfide)。4,The characterization of PPS/HPPS blendsPolymer blends consisting of linear poly(phylene sulfide)(PPS)and hyperbranched PPS(HPPS)were obtained in melt。The solid-state properties of PPS and their blends were investigated。The blends prepared by melt mixing turned out to be reactive as shown by the TGA and extraction measurement。Both the storage modulus and loss modulus increased as HPPS content increasing。5,The process of melt spinning of poly(phenylene sulfide)(PPS)The properties of PPS take-up fiber were studied。With the take-up velocity of 400-800m/s,the domestically linear-PPS had the good spinnability。With the increasing of take-up velocity,the tensile strength and the break-up elongation changed little。After storing up for some time,some properties of PPS take-up fiber would vary。Based on the experimental data,the PPS take-up fiber formation mechanism was simulated,such as crystal properties,mechanical performance and shrinkage。6,The post-process of poly(phenylene sulfide)fiberIn the experiments,the effects of drawing rates and drawing temperatures on the post-process of poly(phenylene sulfide)fiber were investigated。The PPS fiber was manufactured and the fiber formation was also discussed。The tensile strength was about 3.7cN/dtex;the break-up elongation was about 22.2%;the boiling water shrinkage was about 9.6%。7,The characterization of PPS/HPPS fiberPPS/HPPS composite were spun and drawn into fibers。Fiber mechanical properties were tested and the results shown that the adding of HPPS could improve fiber mechanical properties。...