Research On Pilotscale Synthesis Of MBS Resin

In this paper, the technique and production of MBS resin at home and abroad was introduced and the development in production, technology and market of MBS resin was analyzed. And the theoretical basis of SBR latex "particle design" for MBS graft polymerization was described in detail based on the effects of monomer ratio and particle size of SBR latex on impact strength and light transparency of PVC/MBS. The polymerization process of SBR latex and the effects of the emulsifier amount, reaction temperature and stirring rate on particle size and the polymerization stability of SBR latex were investigated experimentally in pilotscale based on the recipe of small scale experiment of SBR latex The pilotscale recipe and process conditions were determined:Bd/St=70/30 (by weight); the amount of emulsifier was 1.70 based on monomer; reaction temperature was 65±1℃; stirring rate was 200r/min; the final conversion was 90%; and the reaction time was 24h. Then the theory basis of "particle design" of MBS grafting latex was described and the effects of grafting sequence of MMA and St, grafting ratio and rubber phase content on impact strength of PVC/MBS and grafting polymerization temperature on grafting ratio of MBS resin were investigated. And the pilotscale recipe and process conditions were determined:the weight ratio of SBR latex to shell monomer was 71.5/28.5 (by weight); the grafting sequence was St first and then MMA; the reaction temperature was 60±1℃; the grafting ratio was 70%-80%; and the reaction time was 10h. Finally, the coagulation mechanism of polymer latex and the coagulation process of MBS grafting latex were reviewed And the effects of the coagulant kind and amount, charging sequence, coagulation temperature and the ratio of coagulant aqueous solution amount to MBS latex amount on bulk density and particle size distribution of MBS were investigated experimentally. The coagulation process conditions of MBS latex were concluded:sulfuric acid as coagulant, using counter agglomeration process, pH controlled at 2-3, emulsion breaking temperature 75℃and the weight ratio of water to latex as 5.