接枝丙烯酰胺共聚物的溶液性能和微结构

Solution Properties and Microstructure of Branched Acrylamide-Based Copolymers

采用水溶液自由基聚合法合成了新型的丙烯酰胺(AM)/4-乙烯苄基辛烷基酚聚氧乙烯(18)醚(VE)/2-丙烯酰胺基-2-甲基丙磺酸钠(NaAMPS)接枝共聚物(PAE),以解决驱油聚合物抗高盐性能差的难题.通过傅里叶变换红外(FT-IR)光谱和核磁共振氢谱(1HNMR)对PAE的分子结构进行了表征.PAE盐溶液显示了两次盐增稠和热增稠效应.对于VE摩尔分数为0.93%的PAE,当其质量浓度为2.0g·L-1时,于30℃在5.0和90.0g·L-1NaCl溶液中的表观粘度分别为1167.0和338.0mPa·s,显示了优异的增粘和抗盐能力;并且于85℃在5.0g·L-1NaCl溶液中的表观粘度仍达685.0mPa·s,显示了良好的耐温性能.PAE还具有较好的表、界面活性.扫描电镜(SEM)照片显示,PAE在纯水中形成了独特的缔合结构,而且在盐水溶液中也形成了连续的微结构,这表明在水中伸展的分子链在盐水中的构象仍然较伸展.

Novel branched acrylamide-based copolymers （PAE） were synthesized by an aqueous free radical copolymerization technique using acrylamide （AM）,sodium 2-acrylamido-2-methylpropane sulphonate （NaAMPS） and p-vinylbenzyl-terminated octylphenoxy poly（ethylene oxide） （VE,polymerization number：18） to improve the poor salt resistance of the oil-flooding polymer at high salt concentrations.The PAE polymer was characterized with Fourier transform infrared （FT-IR） spectroscopy and proton nuclear magnetic resonance （1H-NMR）.The PAE brine solutions exhibited salt-thickening twice and heat-thickening twice over the ranges of NaCl concentration and temperature.For 2.0 g·L^-1 PAE containing 0.93% （molar fraction） VE,the apparent viscosities of 5.0 and 90.0 g·L^-1 NaCl solutions were 1167.0 and 338.0 mPa·s at 30 ℃,respectively.This showed the excellent thickening property and salt resistance of the polymer.The apparent viscosity of the 5.0 g·L^-1 NaCl solution was still up to 685 mPa·s at 85 ℃,which exhibited good heat resistance of the polymer.Moreover,the polymer showed good surfactant and interfacial activities.The scanning electron microscope （SEM） morphologies showed that unique associated structures were formed for PAE in water and continuous network structures were still formed in the brine solution of PAE.Results indicated that the extense polymer chains in water were still able to expand comparatively in the brine solution.