聚N-异丙基丙烯酰胺类聚合物的合成与表征

【作者】 胡晖；

【导师】 宁荣昌； 范晓东；

【作者基本信息】 西北工业大学 ， 材料学， 2001， 硕士

【摘要】 对聚N-异丙基丙烯酰胺（PNIPAm）均聚物的合成与表征作了系列研究。通过改变聚合条件——采用多种溶剂，不同的引发剂，改变引发剂的用量，反应时间，反应温度合成了不同分子量的PNIPAm均聚物。采用溶液聚合法合成了不同配比的NIPAm/丙烯酸甲酯（MA），NIPAm/丙烯酸乙酯（EA），NIPAm/丙烯酸丁酯（BA），NIPAm/丙烯酸（AAc），NIPAm/丙烯酰胺（AM）的二元线型共聚物，用红外光谱和DSC对它们结构与组成进行了表征。研究了共聚物组分比、缓冲溶液pH值、NaCl电解质溶液浓度对共聚物温敏性能的影响，用大分子的链微观结构理论对实验现象作了解释。在远高于试样低临界溶液温度（LCST）下，采用逐步降温法测定了不同线型结构共聚物的溶胀比，首次提出了临界线型水凝胶形成温度的概念，指出了它具有与LCST相似的物理意义，两者的差值可以表征聚合物对温度响应的灵敏程度。最后，采用逐步降温法测定了包覆不同含量中性红的PNIPAm均聚物和P（NIPAm/丙烯酸甲酯）共聚物膜在pH7.0缓冲溶液中的中性红释放规律，结果表明PNIPAm类聚合物材料对包覆的小分子具有明显的温敏释放过程。更多还原

【Abstract】 The synthesis of Poly(N-isopropylacrylamide) was studied in various conditions such as in various solvents,initiators and different polymerization temperatures and time. Poly(N-isopropylacrylamide-co-methylacrylate) ,Poly(N-isopropylacrylamideco-ethylacrylate),Poly(N-isopropylacrylamide-co-butylacrylate),Poly(Nisopropylacrylamide-co-arylic acid) and Poly(N-isopropylacrylamide-co-acryamide) were synthesized by using solution free radical polymerization technique.The segmental structures obtained, monomer抯 compositions in copolymers were characterized using infrared spectroscopy and DSC technology. The study also focused on the influence of copolymers?chain structure, different pH value, and concentrations of NaCI electrolyte solution on thermo-sensitive behaviors of these polymers. Starting at a far higher temperature of samples?lower critical solution temperature (LCST), the swelling ratios of both homo- and copotymers were measured by lowering swelling temperature gradually under an equilibrium state. It is the first time in this study that a concept of a lower critical gel formation temperature (LCGFT) for these polymers was proposed. The results indicated, that although LCGFT possesses the similar significance comparing with LCST, it is more valuable in practical applications.Finally, the deliver and release rule of neutral red which was loaded into the Poly(N-isopropylacrylamide) and Poly(N-isopropylacrylamide-comethylacrylate) was studied in phosphate buffer pH=7.O by the method of gradiently controlling temperature. The results suggested that the Poly(N-isopropylacrylamide) possesses the potential to control the dilivery of small molecule via temperature variation.更多还原