【作者】 周莲；

【导师】 刘晓亚；

【作者基本信息】 江南大学 ， 应用化学， 2004， 硕士

【摘要】 本文利用大分子单体技术,制备了包括凝胶在内的具有双亲性的聚合物,对它们进行表征及特性的研究。在乙醇和水的混合溶剂中采用分散聚合法制备了双亲性的聚r-己内酰改性丙烯酸酯/甲基丙烯酸凝胶(P(FAn/MAA)),考查了不同交联度对体积相转变温度也即上限临界溶解温度(UCST)的影响及不同浸渍溶剂比,温度,pH值等对凝胶溶胀率(SR)的影响。发现交联度是影响凝胶UCST的重要因素,在溶胀率的测定中,随浸渍溶剂中乙醇浓度的变化,凝胶的SR先增加后减小,随温度升高,凝胶的SR增加,同时凝胶表现出了一定的pH敏感性。通过自由基聚合法合成了具有温敏性的双亲二元共聚物聚丙烯酸/r-己内酰改性丙烯酸酯(PAFn)及三元共聚物聚甲基丙烯酸/r-己内酰改性丙烯酸酯/聚乙二醇(PPMAFn),差示扫描量热分析(DSC)研究表明共聚物PAFn的玻璃化转变温度(Tg)随着FA含量的增大而降低。将该类共聚物在选择性溶剂中自组装获得一系列胶束溶液,荧光测试显示,通过自组装的途径获得的胶束在醇/水介质中存在一个温度敏感区,具有明显的相转变温度(UCST),同时也研究了这两种聚合物的胶束浓度,选择性溶剂比例,单体比例,单体FAn 中n(n=1～4)值的变化等对胶束粒径的影响。采用丙烯酸-2-羟基丙酯(HPA)作为改性剂,与羟乙基纤维素(HEC)在硝酸铈铵/乙二胺四乙酸(CAN/EDTA)氧化还原体系下进行接枝反应。通过红外光谱对羟乙基纤维素接枝产物进行了表征。用正交实验法研究了羟乙基纤维素与丙烯酸-2-羟基丙酯的配比和工艺,引发剂的用量,反应温度和反应时间对接枝反应的影响,确定了最佳的配方。然后做了单因素实验,研究了CAN,EDTA,HPA的浓度,聚合温度和时间对接枝百分率,单体转化率和接枝效率的影响。对接枝物在选择性溶剂丙酮中的自组装行为研究表明其在水与丙酮的混合溶剂中能形成核-壳型球状胶束;采用动态激光光散射研究了接枝单体及水与丙酮的配比对胶束尺寸的影响。更多还原

【Abstract】 Amphiphilic linear polymers and gels were prepared by macromonomer technology. The structure and properties of these polymers were studied. Amphiphilic temperature-sensitive gels composed of FA and MAA were synthesized by dispersion polymerization in the mixture of ethanol and water. The effect of different crosslinking degree on the gels’ upper critical solution temperature (UCST) was studied. The influence of the ratio of mixed solvents, the temperature of the system and the pH value on the gel’s swelling ratio (SR) was investigated. The experiment result indicated that with the increase of ethanol content in mixture of ethanol/water, the SR of gels increases at first then decrease, and the SR of gels increases with the increasing of temperature. Other wide, the gels have the pH-sensitive ability. The amphiphilic copolymer PAFn and copolymer PPMAFn with temperature-sensitive property were synthesized by free radical polymerization. The thermal behavior of these copolymers was characterized by DSC, and the result indicated that the glass transition temperature (Tg) of the copolymer decreased with the increasing of FA content. A series of micelle solutions were prepared in selective solvents by means of self-assembly. The results of spectrophotometer showed these copolymers have thermosensitive property in ethanol/water mixture, they have an apparent phase-transition phenomenon at the Upper Critical Solution Temperature (UCST). Furthermore, the effects of the concentration of polymer solution, the ratio of selective solvents, the ratio of monomers, the n value of monomer FAn on the sizes of micelles were studied.The modifier 2-Hydroxy Propyl Acrylate(HPA) was grafted on Hydroxyethyl Cellulose(HEC) by using cerium ammomium nitrate/disodium ethylendiamine tetracetic aicd(CAN/EDTA) redax system as the initiator. The grafted copolymer was characterized by IR. The influence of ratio of HEC and HPA, the initiator content, reaction temperature and reaction time on grafted copolymerization were studied and the optimal formula and technology were determined by the means of orthogonal experiments. Then the single factor experiments were carried out, though which the effects of the concentrations of CAN、EDTA、HPA, polymerization temperature and time on the grafting reaction were investigated in terms of the grafting percentage(%G) , grafting conversion(%C) of the monomer and grafting efficiency(%E). The core-shell structure micelles can be formed by self-assembly of the graft copolymer in selective mixture solvent of water/acetone. The influence of the monomer, the ratio of water and acetone on the micelle size was investigated by dynamic laser light scattering.更多还原