苯乙烯与甲基丙烯酸甲酯共聚制备气化模材料研究

发布时间：2018-03-05 07:39

  本文选题：苯乙烯　切入点：甲基丙烯酸甲酯　出处：《武汉工程大学》2015年硕士论文　论文类型：学位论文

【摘要】：气化模铸造技术能实现精密、高效、批量、清洁生产,而获得所需要的铸件。可发性苯乙烯/甲基丙烯酸甲酯共聚物珠粒是用于制作气化模模样的原始材料之一。本论文以苯乙烯、甲基丙烯酸甲酯为原料,过氧化二苯甲酰为引发剂,碱式碳酸镁和聚乙烯醇作为复合分散剂,甲基丙烯酸为助发泡功能单体,通过悬浮聚合的方法制备了预发性共聚物珠粒,采用气发泡方法制备了苯乙烯/甲基丙烯酸甲酯共聚物气化模材料,并探索了其合成的最佳条件。采用扫描电子显微镜和热重分析法对其微观结构与热降解行为进行了表征与分析,并研究了其热氧化降解动力学。此外,还对对聚合物珠粒的发泡倍率及微观结构、单体残留量、料灼烧残留量进行测定。得出如下的结论:1.制备苯乙烯/甲基丙烯酸甲酯共聚物原料中苯乙烯:甲基丙烯酸甲酯:甲基丙烯酸体积比为7:4:1。制备合格粒径的苯乙烯/甲基丙烯酸甲酯珠粒的最优条件为:水油比6:1、搅拌速度450 r/min、温度85℃。苯乙烯/甲基丙烯酸甲酯共聚物珠粒大小均匀,粒径为500μm。2.发泡后聚苯乙烯/甲基丙烯酸甲酯共聚物内孔直径为20μm~80μm。发泡功能单体甲基丙烯酸的加入显著提高其内孔直径,聚苯乙烯/聚甲基丙烯酸/聚甲基丙烯酸甲酯共聚物的内孔直径为40μm~100μm。在相同发泡条件下,添加甲基丙烯酸助发泡功能单体的聚苯乙烯/聚甲基丙烯酸/聚甲基丙烯酸甲酯共聚物珠粒的发泡倍率为39.2倍,与聚苯乙烯/聚甲基丙烯酸甲酯共聚物珠粒的发泡倍率相比提高了21%。3.聚苯乙烯/甲基丙烯酸甲酯共聚物和聚苯乙烯/聚甲基丙烯酸/聚甲基丙烯酸甲酯共聚物的残留率均低于0.5%,满足QBT4009-2010标准中单体残留率要求。聚合物珠粒灼烧残留率均低于0.7%,其灼烧残留率由高到低依次为:聚苯乙烯聚甲基丙烯酸甲酯苯乙烯/甲基丙烯酸甲酯共聚物苯乙烯/甲基丙烯酸甲酯/甲基丙烯酸共聚物。4.热重分析结果表明聚苯乙烯/聚甲基丙烯酸/聚甲基丙烯酸甲酯共聚物在400~450℃热分解速度最快,450℃热分解失重为95%。采用Ozawa模型模拟聚苯乙烯/聚甲基丙烯酸/聚甲基丙烯酸甲酯共聚物的热降解动力学,其热降解活化能为75~105kJ/mol。
[Abstract]:Gasification mold casting technology can achieve precision, high efficiency, batch, clean production, In this paper, styrene and methyl methacrylate were used as raw materials for making gasification mould pattern, and styrene and methyl methacrylate were used as raw materials. The prepackaged copolymer beads were prepared by suspension polymerization with dibenzoyl peroxide as initiator, basic magnesium carbonate and polyvinyl alcohol as composite dispersants and methacrylic acid as auxiliary foaming monomer. Styrene / methyl methacrylate copolymer gasification model material was prepared by gas foaming method. The microstructure and thermal degradation behavior were characterized and analyzed by scanning electron microscopy and thermogravimetric analysis, and the kinetics of thermal oxidation degradation was also studied. The foaming rate, microstructure and monomer residue of polymer beads were also studied. The following conclusion is drawn: 1. The volume ratio of styrene to methyl methacrylate in the preparation of styrene / methyl methacrylate copolymers is 7: 4: 1. The optimum conditions are as follows: water / oil ratio 6: 1, stirring speed 450 r / min, temperature 85 鈩，

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