温敏性共聚物P(DMA-co-DAAM)的合成与热缔合行为研究  

Studies on the Synthesis and Thermal-induced Association Behaviors of Thermosensitive Poly( N,N-dimethylacrylamide-co-diacetone acrylamide)

作　　者：郭拥军[1,2] 代刚[1,3] 冯茹森[1,3] 郑超 

机构地区：[1]西南石油大学"油气藏地质及开发工程"国家重点实验室,成都610500 [2]四川光亚聚合物化工有限公司,成都610500 [3]西南石油大学化学化工学院,成都610500

出　　处：《高分子学报》2016年第7期871-879,共9页Acta Polymerica Sinica

基　　金：国家科技重大专项(项目号2011ZX05010-004;2011ZX05011-004)资助

摘　　要：以N,N-二甲基丙烯酰胺(DMA)和双丙酮丙烯酰胺(DAAM)为共聚单体,在水溶液中采用常规自由基聚合以K_2S_2O_8-Na_2SO_3双氧化还原体系为引发剂,合成了一系列具有最低临界溶解温度(LCST)的温敏性聚合物P(DMA-co-DAAM).采用紫外可见分光光度计、动态光散射、芘荧光探针法和变温核磁共振氢谱等多种手段研究共聚物在不同温度下的溶液结构,结果表明共聚物P(DMA-co-DAAM)具有明显的热致缔合行为,在低温下聚合物以单链形式溶解,温度升高超过LCST之后由于P(DMA-co-DAAM)分子链上DAAM侧基发生亲水-疏水性变化,部分疏水链段缔合形成微相分离的胶束聚集体.进一步的研究还表明通过改变共聚物组成和溶液浓度能够有效调节共聚物溶液的缔合转变温度,共聚物P(DMA-co-DAAM)的LCST值与DAAM含量成很好的线性关系,DAAM含量越高LCST温度越低.采用常规自由基聚合所带来的链间异质性以及分子量的多分散性等特点并没有显著影响共聚物P(DMA-co-DAAM)的温敏性.Thermosensitive copolymers with lower critical solution temperature （LCST） were prepared by copolymerization of N,N-dimethylacrylamide and diacetone acrylamide through conventional free radical polymerization in water using K2S2O8-Na2SO3 redox system as an initiator. The thermal responsiveness as well as temperature dependent structure of the copolymer solution was systematically examined through ultraviolet- visible spectroscopy（UV-Vis） , dynamic light scattering （DLS） , fluorescence spectrophotometer and 1H-NMR. All these results demonstrate that P （DMA-co-DAAM）s exhibit a significant thermal-induced association behavior. At lower temperatures P（DMA-co-DAAM） was disolved in the form of unimers while these unimers would transform to micellar aggregates due to the association of hydrophobic segments along the chains at higher temperatures. Such phenomenon was ascribed to the changes in hydrophilic-hydrophobic balance of DAAM pendant groups with increasing in temperature. Further research also implies that the association transition temperature of the copolymer solutions could be effectively regulated by changing the composition and concentration of the copolymers. Lower association transition temperatures could be obtained at higher contents of DAAM, which held a well linear relationship in our experiments. It demonstrates that the inter-chain heterogeneity and polydispersity originating from common radical polymerization exhibit little influence on the thermal sensitive behaviors of P（DMA-co-DAAM）.

关 键 词：双丙酮丙烯酰胺 N N-二甲基丙烯酰胺 亲水/疏水平衡 热缔合 最低临界溶解温度 

分 类 号：O631[理学—高分子化学]