星型疏水缔合聚丙烯酰胺溶液性质的研究

Solution Properties of Star-Shaped Hydrophobic-Associative Acrylamide Copolymer

采用光引发自由基聚合法,用丙烯酰胺和疏水单体十八烷基二甲基烯丙基氯化铵合成了星型疏水缔合聚丙烯酰胺(SHMPAM),研究了SHMPAM的溶液性质。流变性实验结果表明,SHMPAM溶液的临界缔合浓度为1000～1250mg/L;SHMPAM溶液的抗温、抗盐和抗剪切性能与疏水缔合聚合物(AP-P4)溶液的性能相似,且性能优于部分水解聚丙烯酰胺(HPAM)溶液;SHMPAM具有的支臂结构一方面增强了分子链间的缠结,导致聚合物溶液的黏度增加,另一方面SHMPAM的支臂在模拟地层水溶液中易发生分子内缔合,一定程度上降低了聚合物溶液的表观黏度。黏弹性实验结果表明,SHMPAM溶液的黏弹转变频率为0.17Hz,AP-P4溶液的黏弹转变频率为0.56Hz,而HPAM溶液只表现出黏性。

The solution property of star-shaped hydrophobic associative acrylamide copolymer （SHMPAM） which was prepared from acrylamide and octadecyl dimethylallyl ammonium chloride by photoinitiated free radical polymerization was investigated. The copolymer was used in tertiary oil recovery. The obtained rheological results showed that the critical association concentration of the SHMPAM solution was in the range of 1 000 - 1 250 mg/L. SHMPAM was similar to hydrophobic associative polymer（AP-P4） in temperature resistance, salt tolerance and shearing tolerance, and better in performance than partially hydrolyzed polyacrylamide. Arm structure in SHMPAM molecule could increase intermolecular entwisting which led to increasing of the copolymer solution viscosity, but at the same time it was prone to get intramolecular association in simulated formation water, which lowered the viscosity to some extent. The experimental results confirmed that both SHMPAM and AP-P4 possessed obvious viscoelasticity, but partially hydrolyzed polyacrylamide had viscosity only. The viscoelasticity transition frequencies of SHMPAM and AP-P4 were 0.17 Hz and 0.56 Hz, respectively.