Study Of The Wet Extrusion Process And The Properties Of ABS Resin

ABS resin is widely used at present. For its excellent impact strength, heat resistant and chemical resistance, and the processing is simple.ABS has been used widely in household appliances, construction and automotive manufacturing and so on.. There are many ways to prepare the ABS. However, The most common is that ABS resin is carried by melting ABS grafted copolymer and SAN with the screw extruder. Firstly, Poly butadiene latex was synthesized by emulsion polymerization and styrene and acrylonitraile were grafted onto the Poly butadiene rubber particle; secondly, SAN resin was prepared by continuous bulk; third, melting blend the ABS grafted copolymer and SAN resin by screw extruder. In the paper, ABS grafted copolymer was synthesizes by grafted styrene and acrylonitrile onto Poly butadiene rubber and melting blend with SAN resin. The paper mainly studied the effect of wet screw process, mechanical properties and deformation mechanism on the structure and property of ABS resin. The conclusions are as follows:At first,ABS resin was been synthesized by wet extrusion。First, ABS grafted copolymer was carried by emulsion polymerization, and blending the dry ABS grafted copolymer with SAN resin, then granulated by wet extruder. It found that feed port of wet extruder was improved to the open mouth feeding tilt for it had higher water content of raw materials. It was good for successful feeding. The wet extruder added three exhausts to ensured smooth water completely ruled out of stream. It was continuous and stable.Secondly,the paper studied that the effect of water content of grafted polymer, the rubber content, antioxidant content, extruder temperature and screw speed on the mechanical properties of ABS resin. The result showed that ABS resin had been degradation, and the impact strength and yield strength decreased when screw temperature was high. But there was no effect of water content in ABS grafted copolymer on the properties of ABS resin. So the paper concluded the best process parameter:the extrusion temperature is 180℃, screw speed is 200r/min, antioxidants content is 0.154wt%. Scanning electron microscope results experienced that PBA rubber particle uniformly disperse in SAN matrix. And TGA showed that ABS had an excellent thermodynamic stability.Finally,ABS resins with different rubber content and strain rate had different fracture behavior and deformation mechanism. With an increase of rubber content in ABS resin, the impact strength and elongation of it was increase and yield strength of it was decreased. There was a brittle-ductile transition when the rubber content in ABS resin is llwt%. Above this rubber content, the strain rate, yield stress and breaking strength are increased, but elongation. It is obviously that the properties of ABS resin were changed with rubber content and strain rate. It found that there were craze, cavitation and shear yield.