Study On Solvent Recovery Of Polyphenylene Sulfide Production And Self-lubricating Polyphenylene Sulfide Alloys

Polyphenylene sulfide (PPS) is a high-performance engineering plastic;the demands on PPS in our country are rapidly increasing. However,the post-treatment of PPS slurry is so backward that it has been the "bottle-neck" of PPS production. Meanwhile,the use of PPS resin as wear resistance material has not been investigated in detail,so it is significant to solve these problems.This thesis consists of two parts;the first part is the solvent recovery of PPS production. Solvent extraction was adopted to deal with the hexamethylphosphor-amide(HMPA)-containing wastewater. The efficiency was excellent. After six-step extraction,the concentration of HMPA in water-phase was lower than the concentration of phosphorus compounds according to the Discharge Standard of Water Pollutants For Phosphate Fertilizer Industry.The second part is the study on self-lubricating PPS alloys. The methods of mechanical blending and blending in solvent were used to prepare the PPS/PHBA blend. Then the specimens were fabricated by hot-pressing,cold compression molding followed by sintering and injection-molding process respectively according to their different processing properties. The pseudo-plastic rheological property of PPS/PHBA blend was concluded by capillary rheometer. The results of FT-IR and WXRD indicated that the blend was incompatible and was multiphase composite. Differential scanning calorimetry (DSC),thermogravimetry (TO),isothermal thermogravimetric analysis and thermomechanical analysis (TMA) were employed to characterize the heat properties of PPS/PHBA blend. The results indicated that PPS/PHBA blend was heat-resistant and dimensional stable. It is also proved that PPS/PHBA alloy could be used below 250 . In order to obtain thephase structure of PPS/PHBA,scanning electron microscope (SEM) and polarized light microscope (PLM) investigation were performed,and the results revealed that PHBA as regular spherical particles uniformly dispersed in PPS continuous phase. The abrasive property and tensile strength of different polymer alloys were determined. The results showed that PPS/PHBA (the weight percentage of PHBA was 15-25%) had better properties. Its abrasion loss was 6.6mg/120min and its frictional coefficient was about 0.4.Finally,orthogonal experiment method was used to optimize the PPS/PHBA/ PTFE multi-component polymer alloys. The PPS:PHBA:PTFE (3:1:1) polymer alloy exhibited excellent self-lubricity and wear resistance,with a frictional coefficient of 0.19 and abrasion loss of 0.7mg/120min.