Preparation And Properties Of Polyphenylene Sulfide (pps)/inorganic Particles Composites And Fibers

Polyphenylene sulfide fiber is an attractive material because of its excellent high temperature durability,chemical resistance and flame retardance. However,the industrialization of PPS fibers is limited by some disadvantages, such as high spinning temperature,high crystallinity and crystalline rate, which make it difficult to stretch the fiber.Therefore,the strength of fiber isn't able to satisfy the requirement of application.In this paper,two kinds of inorganic particles(CaCO₃,SiO₂)were employed as additive to blend with PPS respectively to prepare PPS/inorganic composites,and the crystallization behavior,dynamical mechanical behavior and rheology were studied.The modified PPS fibers were made by melting spinning and the spinning process was improved.The main works and conclusions were listed as following:1.Three kinds of CaCO₃ particles with differente surface modification were chosen to prepare the PPS/ CaCO₃ composites which were characterized by means of Scanning Electron Microscopy(SEM),Differential Scanning Calorimetry(DSC),mechanical testing and Dynamical Mechanical Analysis(DMA).The results showed that the addition of CaCO₃ with different surface modification all made the crystalline rate and ability decrease.However,the composites system blended with CaCO3 modified by titanate coupling agent(DNZ-311)had the best dispersion and stretching toughness comparing to tie other two compositie systems, which agreed well with the testing results from DMA:The addition of CaCO₃ modified by titanate coupling agent made both storage and loss modulus increase and delayed the stress relaxation.2.Another addictive-nano SiO₂ was chosen to improve the performance of PPS resin.SEM showed that nano SiO₂ dispersed evenly in the PPS matrix. DSC and non-isothermal crystallization kinetics indicated that the addition of nano SiO₂ increased the crystalline rate but decreased the ability of crystallization.Slack time(τ)was the least when the SiO₂ content was 1% by analysis of creep behavior of PPS/ SiO₂ composites,which indicated that nano SiO₂ made the movement of PPS molecular chain easily. Dynamical rheology results showed a decrease of the storage modulus and viscosity of composites with low SiO₂ content,but the storage modulus and viscosity increased sharply with the increasing of SiO₂ content. Mechanical testing results showed that the stretching toughness improved greatly when SiO₂ content is 5%.3.Two kinds of composites were used to spin and the basic performances of fibers were studied.The results showed that the addition of CaCO₃ decreased the spinning temperature and increased the strength of fibers. However,the PPS/ SiO₂ composite fibers had higher orientation and lower crystallinity.The addition of SiO₂ increased the fiber strength and the breaking energy and also improved the spinning process,which is useful for the industrialization of PPS fibers.