疏水缔合改性丙烯酰胺共聚物的合成

采用自由基胶束聚合法合成了丙烯酰胺（AM）/丁基苯乙烯（BS）/2-甲基-2-丙烯酰胺基丙磺酸钠（NaAMPS）疏水缔合水溶性共聚物PASA，PASA避免了目前疏水缔合聚合物溶液热稳定性差的问题.研究得到了适宜的反应条件，包括NaAMPS、BS和引发剂加量相对于单体总量的摩尔分数分别为10%、2.5%和0.07%，总单体在水里的质量分数为10%，SDS在水里的质量分数为6.0%，反应温度50℃，pH=6～7，反应时间12 h.采用以上反应条件得到PASA的临界缔合质量浓度为0.05 g·dL^-1，对应的水溶液表观黏度为283 mPa·s，质量浓度为0.1 g·dL^-1的水溶液表观黏度为1020 mPa·s.采用元素分析、UV、FT-IR和¹HNMR证实了共聚物的分子结构;DSC分析表明了共聚物分子链中存在疏水嵌段.

Synthesis of hydrophobically associating acrylamide-modified terpolymer

The hydrophobically associating water-soluble acrylamide-modified copolymers（PASA）with butyl styrene（BS）and sodium-2-acrylamido-2-methylpropane sulphonate（NaAMPS）were synthesized by the micellar free radical copolymerization technique.The two key problems including the very poor water-solubility and thermal stability of the hydrophobically associating water-soluble polymers are overcome in this study，which are due to the incorporation of the anionic monomer NaAMPS into the PASA molecules and the phenyl group from BS which can stabilize the hydrophobic units.The influence of reaction conditions on the apparent viscosity of PASA aqueous solution was studied，and the suitable reaction parameters including mole percentage of NaAMPS，mole percentage of BS，mole percentage of initiator，relative to total monomers，mass percentage of total monomers in water，mass percentage of surfactant in water，reaction temperature，pH value and reaction time were 10%，2.5%，0.07%，10%， 6.0%，50℃，pH 6—7 and 12 h，respectively.Under the above reaction conditions，the polymer was synthesized，which critical association mass concentration was about 0.05 g·dl^-1.The apparent viscosities of 0.05 g·dl^-1 and 0.1 g·dl^-1 PASA aqueous solution were 283 mPa·s and 1020 mPa·s，respectively.The synthesized product was characterized with UV，FT-IR，¹H-NMR and elemental analysis.The block-structure of the polymer was shown by DSC measurement，which was favourable to the intermolecular hydrophobic association.