摘要
利用表面张力法对甲基丙烯酰氧乙基二甲基苄基氯化铵(简称DMBAC)在水溶液中的表面活性进行了测试并确定了其CMC值.研究了丙烯酰胺(AM)和DMBAC在水溶液中的共聚合反应行为,测定了AM与DMBAC共聚反应的竞聚率;IR,1H-NMR对共聚物的结构进行了表征;13C-NMR和DSC分析了单体DMBAC浓度对共聚产物微结构的影响;芘作为荧光探针测定了共聚物水溶液的疏水缔合性质.实验结果表明当共聚单体DMBAC浓度大于CMC时DMBAC倾向于均聚,DMBAC在共聚产物主链上呈微嵌段的形式分布.当共聚单体DMBAC浓度小于CMC时,DMBAC与AM倾向于无规共聚.
The surface activity of cationic DMBAC （ dimethyl methacryloyloxyethyl benzyl ammonium chloride） was revealed by measuring surface tension and estimating of critical micelle concentration （ CMC）. The copolymerization of acrylamide （ AM） and DMBAC was studied in aqueous solution at above and below CMC of DMBAC,respectively. The reactivity ratios r1 and r2 were determined by the Fineman-Ross method. IR and 1H-NMR spectra afford information about polymer structure. The compositions of copolymers were calculated by UV spectrophotometer. The intrinsic viscosity values of the copolymers were measured by the Ubbelohde-type Viscometer. Molecular weight （ Mw ） and polydispersity index （ PDI） of the copolymers were measured by gel permeation chromatography （GPC）. The effect of DMBAC concentration on the microstructure of the copolymers was analyzed by 13C-NMR and DSC spectra. The property of hydrophobic association of the copolymers was characterized by using pyrene fluorescence probe technique. The experimental results of copolymerization showed that the reactivity ratios of monomers were different at above and below CMC of DMBAC,r1（AM） = 0. 65,r2（DMBAC） = 1. 41 and r1（AM） = 0. 74,r2 （ DMBAC） = 0. 91,respectively. These results suggested that DMBAC monomers may distribute in a microblock sequence in the copolymer chain at above CMC of DMBAC,and in a random sequence at below CMC of DMBAC. The structures of copolymers were proved again by 13 C-NMR and DSC spectra. The copolymer CP-1 with microblock sequences showed stronger hydrophobically associating than the copolymer CP-2 with random sequences.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2010年第4期435-441,共7页
Acta Polymerica Sinica
