水溶性两性共聚物的表征及其溶液性质

Characterization and Solution Properties of a Water-Soluble Amphoteric Copolymer

以甲基丙烯酰氧乙基-N,N-二甲基-N-丙磺酸胺盐(DMPS)和丙烯酰胺(AM)为单体,采用反相乳液聚合法制备了一种新型两性共聚物poly(AM-co-DM PS)。采用核磁共振、傅里叶变换红外光谱、热重分析和元素分析对该两性共聚物进行了结构和组成表征,并利用紫外分光光度计和乌氏黏度计对其溶解性及溶液的黏度进行了测定。表征结果显示,对于两性共聚物poly(AM-co-DMPS),FTIR谱图中1187cm-1处出现明显的SO3-的特征吸收峰,AM与DMPS的质量比与原料配比基本吻合,在低于300℃时具有较好的热稳定性。实验结果表明,两性共聚物poly(AM-co-DMPS)中DMPS含量越高,在水中的溶解性越差;随外加盐浓度的增大,两性共聚物poly(AM-co-DMPS)的溶解性变好、特性黏数和比浓黏度增大,具有明显的反聚电解质性质。

Amphoteric copolymers poly （AM - co - DMPS ） were prepared by inverse emulsion copolymerization of acrylamide （AM） and N, N - dimethyl - N - methacryloyloxyethyl - N - （ 3 - sulfopropyl） ammonium（DMPS）. The copolymers were characterized by means of FTIR, 1H NMR, element analysis and TG - DTG. The obvious SO3 characteristic absorption is indicated by FTIR and the copolymers exhibit good thermal stability below 300 ℃. The solutions of the copolymers were studied by means of UV spectrophotometer and Ubbelohde viscometer. The higher the DMPS content in the copolymer is, the lower the solubility in water is. The copolymers can be also dissolved in salt solution. Even in high concentration salt solutions and at high temperatures, viscosities of the copolymer solutions are high. So the copolymers show obvious antipolyelectrolyte characteristics.