Research Of Hybrid Polyphenylene Sulfide (PPS) Modified Fiber

With the increasing of haze weather, the national environmentalprotection agency increases the regulation of atmospheric pollution,leading to the bag filter demand strongly. PPS fiber with its thermalstability, corrosion resistance self flame retardant property become theone important filter material of high temperature gas and liquid phasesarea. Filter bag made by PPS fiber was core components of the deviceusing in high temperature, high corrosion and filtering PM2.5, causingthe attention by the governments. With the application field and demandof PPS fiber increasing, the shortcoming of PPS fiber, brittleness largeand oxidant easily in high temperature, has been attended by more andmore universities and research units. In response to these problems, thisstudy selects Nano-SiO2, its surface of immobilizing high temperatureantioxidant, blending on PPS modified fiber, in order to obtain hybridPPS modified fiber with higher oxidation resistance and othercomprehensive performance.This study mainly research content including the following aspects:Study of antioxidants immobilizing on the surface of Nano-SiO2. Firstly, in the action of ultrasonic, Nano-SiO2was alkylationmodified using silane coupling agent(KH560). Then a kind of hightemperature antioxidant(KYN-818) was added in the system, reactingunder the action of ultrasonic chemical. Modified Nano-SiO2, whichsurface immobilized the antioxidant was screened the best modificationprocess through orthogonal experiment. This study was discussed theeffect of ultrasonic temperature, time and power on the immobilizedresult through the testing of surface hydroxyl number and lipophilicdegree. The structure and dispersion of modified Nano-SiO2was studiedby Fourier infrared spectrum (FT-IR) and scanning electron microscope(SEM). It was shown that the best ultrasonic chemical process is thetemperature in60℃, the time in40min, the power in80W. The surfacehydroxyl number and lipophilic degree of modified Nano-SiO2preparedby the optimal modification craft, were0.826and37.5%, respectively.KH560and antioxidant KYN-818were immobilized in form of chemicalon the surface of Nano-SiO2. The surface hydroxyl number of Nano-SiO2was decreased, the interaction force between particles being abate, andthe reunion phenomenon being weaken. Otherwise, the modifiedmechanism of the alkylation of Nano-SiO2and its surface immobilizingthe antioxidant was discussed preliminary.The study of hybrid PPS modified master batch. The hybrid PPSmaster batch was prepared by the PPS matrix added the antioxidant, Nano-SiO2and modified Nano-SiO2, using the twin screw extruderthrough the process of extrusion, cooling, cutting grain. The effect ofadding material and quantity on structure and properties of hybrid PPSmodified master batch was studied by differential scanning calorimeter(DSC), X-ray diffraction (XRD), SEM and FT-IR and other instruments.The result was shown that new functional groups was not formedbetween the antioxidant and PPS. Adding antioxidants alone to improvethe performance of PPS composites is inferior to adding Nano-SiO2. Thethermal performance of PPS composites was greatly improved causingthe adding of modified Nano-SiO2, the crystallinity of which beingincreased highest by54.7%, comparing with pure PPS. The Nano-SiO2has the effect of heterogeneous nucleation in crystallization process ofPPS composites, having good dispersibility and compatibility with PPSmatrix, no obvious phenomenon of reunion, and achieving the effect ofmono-disperse. SP3hybridization was formed by Si atoms in Nano-SiO2and S atoms in PPS macromolecular by XRD analysis. Meanwhile, thecompound adding of Nano-SiO2and antioxidants lead to the unit cell sizesmaller, playing a role in grains fining. PPS crystals closely was packed,and the degree of crystallinity was improved.The study of hybrid PPS modified fiber. Hybrid PPS modified fiberwas prepared by spinning-drawing two-step. Effect of different addingmaterial and quantity on structure and properties of hybrid PPS modified fiber was discussed by a series of instruments and methods such as DSC,the sound velocity meter, electronic single yarn strength tester and testingof materials resisted to high temperature oxidation. It was shown that thestate of aggregation structure of hybrid PPS modified fiber was improvedcausing the compound adding of Nano-SiO2and antioxidants. resulting inmaximum breaking strength of PPS modified fiber to3.18cN/dtex, anddynamic OIT of which increased by9.87℃, to469.87℃, comparing withPPS modified fiber adding Nano-SiO2alone. The maximum strengthretention of hybrid PPS modified fiber could reach to approximately90%after the heat treatment96h at the temperature of230℃. It was indicatedthat the thermal oxidation resistance and thermal stability of hybrid PPSmodified fiber was ameliorated due to the compound Nano-SiO2andantioxidant coordinately. Simultaneously, the antioxidant mechanism ofthe modified Nano-SiO2in the process of thermal oxidation on hybridPPS fiber was preliminary discussed.