耐盐型聚丙烯酰胺的制备及其盐水溶液流变性能研究

Preparation of salt-tolerant polyacrylamide and study on rheological properties of salt solution

以丙烯酰胺(AM)、丙烯酸(AA)、单体AR,通过自由基水溶液聚合方法制备了一种耐盐型聚丙烯酰胺SPAM。通过红外光谱仪测试分子结构,六速黏度计测试不同浓度溶液表观黏度,透射电镜观察不同盐水中聚合物分子的微观聚集态,使用流变仪测试溶液的触变性,及不同盐水中的耐温耐剪切性能。结果表明,通过红外测试,所合成聚合物基本满足预先设计的分子结构;最佳的AR单体加量为0.3%,得到的SPAM聚合物CAC为300 mg/L。透射电镜观察聚合物分子的微观聚集态,盐可压缩疏水微区,使聚合物结构黏度更紧密,表现出良好触变性,在5%CaCl_(2)盐水溶液0.35%SPAM聚合物表观黏度可以达到150 mPa·s;120℃、170 s^(-1)的条件下,剪切60 min,最终黏度可以保持在57.8 mPa·s,黏度保持率为80%,表现出了优异的抗盐性能。

A salt-tolerant polyacrylamide SPAM was prepared by free radical aqueous solution polymerization with acrylamide(AM),acrylic acid(AA)and monomer AR.The molecular structure was tested by infrared spectrometer.The apparent viscosity of different concentrations of solution was tested by six-speed viscometer.The microscopic aggregation state of polymer molecules in different brines was observed by transmission electron microscopy.The thixotropy of the solution was tested by rheometer.The temperature and shear resistance of different brines were tested.The results show that the synthesized polymer basically meets the pre-designed molecular structure by infrared test.The optimal AR monomer dosage was 0.3%,and the obtained SPAM polymer CAC was 300 mg/L.The microscopic aggregation state of polymer molecules was observed by transmission electron microscopy.The salt compressible hydrophobic micro-region makes the polymer structure viscosity closer and shows good thixotropy.The apparent viscosity of 0.35%SPAM polymer in 5%CaCl_(2) salt solution can reach 150 mPa·s.Under the condition of 120℃,170 s^(-1),shear 60 min,the final viscosity can be maintained at 57.8 mPa·s,viscosity retention rate of 80%,showing excellent salt resistance.