【作者】 李莹；

【导师】 申凯华；

【作者基本信息】 大连理工大学 ， 应用化学， 2012， 硕士

【摘要】 本论文将长碳链烷基胺聚氧乙烯醚应用于苯乙烯聚合反应中,通过GPC表征所制备的聚苯乙烯(polystyrene, PS)呈双峰或三峰分布。通过研究证实,低分子量部分由过氧化二苯甲酰(BPO)/烷基胺聚氧乙烯醚、BPO/连二亚硫酸钠(Na2S204)组成的两种氧化还原体系引发聚合而得。高分子量端的数均分子量最高达1.25×106,属于超高分子量聚苯乙烯(Ultra-high molecular weight polystyrene, UHMWPS),是由体系中BPO氧化烷基胺聚氧乙烯醚所得氧化胺引发聚合而得。基于此研究发现,本论文主要是通过开发新型反应型表面活性剂——长碳链烷基胺聚氧乙烯醚氧化物(氧化胺),在不添加其他任何引发剂、链转移剂、电解质等的条件下,将未经任何提纯操作的工业级氧化胺进行苯乙烯乳液聚合,制备出具有一定间规度的窄分子量分布的超高分子量聚苯乙烯。本论文主要包括以下几个方面：通过H202氧化反应在高转化率下制备长碳链烷基胺聚氧乙烯醚氧化物,通过AP-ES及表面张力测试,对氧化胺的结构和表面活性进行表征,结果表明制备的氧化胺具有较好的表面活性。系统的考察了烷基胺聚氧乙烯醚氧化物聚合体系中聚合反应时间、水与苯乙烯的用量比、氧化胺用量及烷基胺聚氧乙烯醚对聚合反应动力学、聚苯乙烯的微观结构、分子量及其分布、玻璃化转变温度及结晶性能的影响,并采用GPC、1H-NMR,13C-NMR, DSC, FT-IR对聚合所得UHMWPS进行表征。研究表明,该体系制备的UHMWPS分子量随聚合反应转化率逐渐增加,分子量分布保持较窄分布,具有“活性”聚合特征。UHMWPS的数均分子量M。最高达2.53×106,分子量分布指数最小为1.10。烷基氧胺作为聚合模板,可控制UHMWPS的微观结构。由’H-NMR及溶解提取法计算得UHMWPS为富间规结构,sPS含量大于84%。通过DSC测试,UHMWPS在220-290℃之间有较宽的结晶熔融吸热峰。这种新型的具有稳定自由基特征的界面反应型表面活性剂价格低廉,易于制备,通过简单的乳液聚合反应,制备出具有一定立构规整性的窄分子量分布的UHMWPS,为UHMWPS及富间规聚苯乙烯的合成提供了新的研究方向。更多还原

【Abstract】 In this paper, long chain ethoxylated fatty amines were used as surfactant of styrene emulsion polymerization. Unlike other types of styrene polymerization, Polystyrene (PS) obtained from this polymerization system showed double or trimodal distribution characterized by GPC. Through studying, the low part molecular weight was obtained from BPO/ethoxylated fatty amines initiator system, meanwhile, the lower part was from BPO/Na2S2O4initiator system. The number averaged molecular weight of the high part molecular weight had reached1.25X10, which was in Ultra-high molecular weight polystyrene’s (UHMWPS) range. The UHMWPS was obtained from the ethoxylated fatty amine oxides prepared from BPO’s oxidation.Based on the study, this paper had developed novel reactive surfactants long chain ethoxylated fatty amine oxides (AO) of industrial grade for styrene emulsion polystyrene, without adding any other initiator, chain transfer agent and electrolyte and purification process, and had got UHMWPS with narrow molecular weight distribution and rich syndiotacticity. The main contents are listed as follows:Long chain ethoxylated fatty amine oxides were synthesized from H2O2oxidation reaction with high conversion. The chemical structure and surface properties were tested by API-ES and surface tension-meter. Those amine oxides showed good surfactivity and low CMC concentration.The AO initiator systems were studied systematically. The effects of reaction time, H2O/styrene ratio, amount of amine oxides and corresponding amine addition on the rate of emulsion polymerization, polystyrene’s microstructure, molecular weight and its distribution, glass transition temperature and crystalline properties were investigated. Synthetic UHMWPS was characterized with GC、1H-NMR、13C-NMR, DS、FT-IR.The results showed that the number averaged molecular weights of the obtained UHMWPS increased with monomer conversion, presented certain "living" characteristics. The number averaged molecular weights gave a highest value of2.53X106and molecular weight distributions (MWD) were unimodal throughout the reaction and the minimum MWD was l.10. As polymerization matrix, long chain ethoxylated fatty amine oxides could control polymer’s microstructure. The microstructure confirmed by NMR, DSC and solvent extraction method showed that UHMWPS was rich in syndiotactic structure (rr%>84%) and had wide crystal melting temperature from220oC to290oC.This novel interface matrix polymerization initiator with stable free radicals characteris-tics and emulsifying property could be prepared easily and cheap in price, meanwhile, provide a new method for UHMWPS and rich syndiotactic polystyene’s research.更多还原