本文選題：苯乙烯　切入點(diǎn)：甲基丙烯酸甲酯　出處：《武漢工程大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：氣化模鑄造技術(shù)能實(shí)現(xiàn)精密、高效、批量、清潔生產(chǎn),而獲得所需要的鑄件�？砂l(fā)性苯乙烯/甲基丙烯酸甲酯共聚物珠粒是用于制作氣化模模樣的原始材料之一。本論文以苯乙烯、甲基丙烯酸甲酯為原料,過氧化二苯甲酰為引發(fā)劑,堿式碳酸鎂和聚乙烯醇作為復(fù)合分散劑,甲基丙烯酸為助發(fā)泡功能單體,通過懸浮聚合的方法制備了預(yù)發(fā)性共聚物珠粒,采用氣發(fā)泡方法制備了苯乙烯/甲基丙烯酸甲酯共聚物氣化模材料,并探索了其合成的最佳條件。采用掃描電子顯微鏡和熱重分析法對其微觀結(jié)構(gòu)與熱降解行為進(jìn)行了表征與分析,并研究了其熱氧化降解動力學(xué)。此外,還對對聚合物珠粒的發(fā)泡倍率及微觀結(jié)構(gòu)、單體殘留量、料灼燒殘留量進(jìn)行測定。得出如下的結(jié)論:1.制備苯乙烯/甲基丙烯酸甲酯共聚物原料中苯乙烯:甲基丙烯酸甲酯:甲基丙烯酸體積比為7:4:1。制備合格粒徑的苯乙烯/甲基丙烯酸甲酯珠粒的最優(yōu)條件為:水油比6:1、攪拌速度450 r/min、溫度85℃。苯乙烯/甲基丙烯酸甲酯共聚物珠粒大小均勻,粒徑為500μm。2.發(fā)泡后聚苯乙烯/甲基丙烯酸甲酯共聚物內(nèi)孔直徑為20μm~80μm。發(fā)泡功能單體甲基丙烯酸的加入顯著提高其內(nèi)孔直徑,聚苯乙烯/聚甲基丙烯酸/聚甲基丙烯酸甲酯共聚物的內(nèi)孔直徑為40μm~100μm。在相同發(fā)泡條件下,添加甲基丙烯酸助發(fā)泡功能單體的聚苯乙烯/聚甲基丙烯酸/聚甲基丙烯酸甲酯共聚物珠粒的發(fā)泡倍率為39.2倍,與聚苯乙烯/聚甲基丙烯酸甲酯共聚物珠粒的發(fā)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殘留率均低于0.5%,滿足QBT4009-2010標(biāo)準(zhǔn)中單體殘留率要求。聚合物珠粒灼燒殘留率均低于0.7%,其灼燒殘留率由高到低依次為: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.熱重分析結(jié)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℃熱分解速度最快,450℃熱分解失重為95%。采用Ozawa模型模擬聚苯乙烯/聚甲基丙烯酸/聚甲基丙烯酸甲酯共聚物的熱降解動力學(xué),其熱降解活化能為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，

本文編號：1569334