【作者】 关琦；

【导师】 丁伟；

【作者基本信息】 大庆石油学院 ， 化学工程， 2006， 硕士

【摘要】 双水相聚合反应是将一种水溶性单体、引发剂及分散介质溶解在水中,形成均相水溶液,一定条件下进行聚合反应,由于聚合物之间的相互作用,体系发生相分离,两种聚合物分别富集于各自相中,形成互不相溶的水溶性聚合物分散液的聚合反应。它克服普通水溶液聚合高粘、搅拌和传热困难等缺陷,且聚合和使用过程中不存在有机溶剂污染,后处理简单,是制备水溶性聚合物的新方法。但将两种水溶性单体,溶解在分散介质水溶液中进行共聚合,最终形成双水相体系的研究鲜有报道。本论文以此为出发点,以丙烯酰胺(AM)和丙烯酸钠(NaAA)为原料,进行双水相共聚合反应,并对该共聚合反应进行了系统研究。本论文从水溶性聚合物的疏水性差异、聚合物水溶液黏度及聚合体系稳定性角度出发,考察了不同相对分子质量聚乙二醇(PEG)对聚合物双水相乳液体系的乳液状态和稳定性的影响,最终确定 PEG20000 水溶液作为 AM-NaAA 双水相共聚合的分散介质。本论文考察了引发剂浓度、初始单体浓度、乙二胺四乙酸(EDTA)浓度、甲酸钠浓度、尿素浓度、聚合反应温度、体系 pH 值、共聚单体与分散介质摩尔配比、共聚单体摩尔配比以及乳化剂浓度等因素对聚丙烯酰胺(HPAM)特性黏数、HPAM-PEG-水乳液体系稳定性以及单体残留量的影响。最后通过正交实验,确定了该双水相共聚合反应最佳反应工艺参数,得到了聚合物双水相体系乳液的最佳 HLB 值。采用膨胀计法研究了各工艺参数对双水相共聚合反应速率的影响。得到了双水相共聚合反应速率方程以及活化能。采用阴离子度法测定共聚单体在共聚产物中的组成,并用 F-R 等三种方法推导出 NaAA 与 AM 的竞聚率。采用浊度滴定法绘制了不同 PEG 相对分子质量和不同温度下 HPAM-PEG-水体系的相图,随着 PEG 相对分子质量增加,临界分相浓度下降;随着温度升高,临界分相浓度先下降后升高。PEG 及 HPAM 富集相存在疏水性差异,因此 AM 将在两相分配,随着 HPAM 浓度升高,AM 分配系数升高;随着 PEG 浓度升高,AM 分配系数下降;平衡温度也会影响 AM 分配系数,随着温度升高,AM 分配系数升高。最后对 HPAM-PEG-水乳液体系稳定机理进行了初步探讨,促使体系稳定的因素包括:液滴内部高黏度、连续相黏度及引发剂碎片静电作用。更多还原

【Abstract】 Aqueous two-phase polymerization is that the water-soluble monomers,initiator andanother water-soluble polymer are dissolved to form a homogeneous aqueoussolution,then polymerize to form a heterogeneous polymeric disperse aqueoussolution.The two polymers enriched in the disperse and continuous phaserespectively.It overcame the problems of mixing and heat transfer of polymerizationsystem.The aqueous two-phase polymerization was performed in water without anyorganic solvent.It also overcame the pollution and recycle problems of organic solventfor inverse phase suspension polymerization,water-in-oil inverse phase emulsionpolymerization and precipitation polymerization.It’s a new polymerization method forpreparing the water soluble copolymer .It was reported rarely that two water-solublepolymers were dissolved in another water-soluble polymer to copolymerize to formaqueous two-phase polymerization.In this paper,arylamide and acroleic acid sodiumwere selected to form aqueous two-phase polymers,then copolymerization was studied.Polyethylene glyol aqueous solution was selected as the dispersed medium of theaqueous two-phase polymerization for acryamide and acroleic acid sodium systembased on the hydrophobic interaction among water-soluble polymers.The viscositynumber of polymer aqueous solution and the stability of the polymerization system.theeffects of different molecular-weight PEG on emulsion state and stability werestudied,and finally the PEG20000 aqueous solution was the dispersion.The effect of initiator concentration,EDTA concentration,initial monomerconcentration,sodium formate and carbamide concentration,temperature ofpolymerization,pH of the system, monomers,emulsifier and intrinsic viscosity numberof HPAM on stability of HPAM-PEG aqueous emulsion system and monomeruntransformed ratio was studied.At last,by orthogonal,the optimum techonologicalparameters were fixed,and also the best HLB value.The effect of several technological parameters on polymerization velocity werestudied by dilatometer and the kinetics equation and activation energy.In this case,theeffect of the polarity of medium on reactivity ratio was a little by using partialhydrolysis degree to calculate anion degree to measure the reactivity ratio and usingF-R and other methods to measure it.In the last chapter,the phase diagrams of HPAM-PEG-water aqueous system wereobtained by turbidity titration,and the effects of temperature and the molecular weightof PEG were studied.With the increase of the molecular weight of PEG,the criticalphase splitting concentration decreased;with the increase of the temperature,the criticalphase splitting concentration decreased and then increased,it was lowest as whentemperature was 60℃.PEG and the phase enriched in HPAM were different inhydrophobic quality,so AM was dispersed into two phase,as the concenteation ofHPAM increased,the distribution number of AM increased;as the concentration of PEGincreased,the distribution number of AM decreased;as the temperature increased thedistribution number increased.According to the works and experiences,the stabilitymechanism of HPAM-PEG-water aqueous emulsion was discussed primarily.Thefactor were: the high viscosity in the droplet,the viscosity of continuous phase and thestatic electrification fragment.更多还原