Analysis Of Factors Affecting The Quality Of ABS Resins

ABS, an important synthetic resin, is a rubber-toughened thermoplastic copolymerized by monomers of Acrylonitrile( AN),(Butadiene(BD) and Styrene(ST). The disperse phase of ABS is the polybutadiene(PB) rubber particle, and the continuous phase is Styrene-Acrylonitrile copolymer. With the rapid development of China's home appliance and automotive industry, as well as the improvement of people's consumption level, the demand of ABS resin is growing rapidly.Tianjin Dagu Chem. Ltd. ABS plant introduced the American GE company's emulsion grafting-bulk copolymerizing AS-compounding process, and divided into 4 units, including PBL unit, HRG unit, SAN unit and COM unit. The product PBD latex of PBL unit is sent to HRG unit to produce the high rubber graft powder, which is compounding with the SAN particle from SAN unit by the extruder and pelletizing in COM unit to produce the ABS resin.There are various causes that lead to the unstability of the ABS quality. The weak quality competitiveness is common in domestic ABS products. This paper takes the Dagu Chem. Ltd. ABS plant as an example to discuss the influences on ABS quality produced by emulsion grafting-bulk copolymerizing AS-compounding process:1) Chapter II introduced SAN polymer manufacturing process, along with the composition, features, testing methods and quality control index, analyzed the relevant factors on SAN features, including the residual monomer contents of styrene and acrylonitrile, the chain transfer agent, temperature and impurities, and then discussed the influence factors on the controling of SAN polymer quality.2) Chapter III introduced PBD latex manufacturing process, along with the composition and features, discussed the influence factors on PBD latex features, including the residual monomer contents of BD, the dosage of initiator and other additives, temperature, agitator, homogenizer, and homogenization temperature, etc.3) Chapter IV introduced HRG powder manufacturing process, along with the composition and features, discussed the influence factors on HRG powder features, including the dosage of surfuric acid in coagulation, the temperature and agitator of coagulator and cooker, the water-washing and drying process, storage conditions, temperature, etc. 4) Chapter V introduced the compounding process, along with the composition and features, took the DG-MG29 as a example to discuss the influence factors on ABS resin features, including the amount of screen exchanger plugs, feed rates, screw rotational speed, shell temperature, the formula,etc. 5) Synthesizing the chapters above, we consider all the listed influence factors and produce the ABS resin with stable quality.