Abstract:

In order to improve salt resistance, temperature tolerance and stability of the acrylamide-based copolymer, the hydrophobic associating copolymer (DTHAP) of acrylamide (AM) with acrylic acid (AA) and a double-tailed hydrophobic monomer (N-phenethyl-N-tetradecylmethacrylamide, PETMAM) was synthesized by photo-initiated radical polymerization. By measuring apparent viscosity of the hydrophobic associating polymer, the effects of amounts of acrylic acid, salt, surfactant (SDS) and content of the double-tailed hydrophobic monomer on the properties of the copolymer were investigated. The critical associating behavior of the copolymer could be affected by changing the amounts of surfactant and acrylic acid. Then, the amount of surfactant could be reduced by adding NaCl to the solution in the micellar polymerization process. Finally, even at low concentration [0.35%—0.45%(mol)] of hydropobic monomer, the copolymer could exhibit obvious thickness. For the hydrophobic associating copolymer synthesized, its critical association mass concentration was about 0.75 g·L^-1 and its viscosity was 141.5 mPa·s at the concentration of 1 g·L^-1. After ageing for 90 d at 80℃, the apparent viscosity of 2 g·L^-1 DTHAP in 120 g·L^-1 NaCl solution was 47.6 mPa·s. Even in 120 g·L^-1 NaCl and 0.4 g·L^-1 CaCl₂ solution, the viscosity of the copolymer solution could be kept at around 45.9 mPa·s. The copolymer was characterized with FTIR and SEM, and its structure was confirmed.

Key words: photo-initiated radical polymerization, double-tailed hydrophobic monomer, polymers, solution, viscosity

摘要：

通过光引发自由基聚合的方式,将双尾型丙烯酰胺类疏水单体(N-苯乙基-N-十四烷基甲基丙烯酰胺,PETMAM),与丙烯酰胺(AM)、丙烯酸(AA)等水溶性单体进行共聚,制备出双尾型疏水缔合水溶性共聚物(DTHAP),来解决丙烯酰胺类聚合物耐温抗盐性以及稳定性差的难题。通过测定聚合物溶液的表观黏度作为评价其性能的主要手段,考察了丙烯酸加量、盐、表面活性剂(SDS)含量、疏水单体含量等因素对聚合物性能的影响,从而确定了比较理想的反应条件。实验中发现:丙烯酸加量和表面活性剂含量的变化会影响聚合物的临界缔合行为;盐的引入能够显著降低表面活性剂的用量,提高聚合物的增黏效果;疏水单体含量较低时[0.35%～0.45%(mol)],聚合物可以表现出明显的增黏效果。当聚合物浓度为1 g·L^-1时,聚合物的黏度可以达到141.5 mPa·s,其临界缔合浓度(CAC)为0.75 g·L^-1左右。聚合物在120 g·L^-1的NaCl溶液和120 g·L^-1 NaCl、0.4 g·L^-1 CaCl₂溶液中,80℃下老化90 d,黏度分别为47.6 mPa·s和45.9 mPa·s。采用红外光谱、扫描电镜两种手段,表征了聚合物的结构。

关键词: 光引发自由基聚合, 双尾型疏水单体, 聚合物, 溶液, 黏度