耐盐性PAM-AMPS/Fe_(3)O_(4)纳米减阻剂流变性

Rheological Properties of PAM-AMPS /Fe_(3)O_(4) Nano Drag Reducing Agent With Salt Tolerance

采用丙烯酰胺/2-丙烯酰胺基-2-甲基丙磺酸(AM/AMPS)共聚物接枝纳米Fe_(3)O_(4)合成了一种PAM-AMPS/Fe_(3)O_(4)纳米减阻剂,并利用动态流变仪研究了PAM-AMPS/Fe_(3)O_(4)减阻剂的剪切稀释性,分析了纳米Fe_(3)O_(4)、盐含量及剪切作用对其流变行为的影响规律。结果表明:PAM-AMPS/Fe_(3)O_(4)纳米减阻剂的粒径为100~500 nm、黏均分子质量为4.99×10^(6)g/mol;在30℃下,剪切速率大于0.3 s^(-1)时PAM-AMPS/Fe_(3)O_(4)减阻剂表现出显著的剪切稀释特征,该减阻剂具有更复杂的微观结构,其超临界质量分数为0.035%,相比空白聚合物表现出更优良的增黏性能和黏弹性;由于AMPS含有耐温耐盐基团,在NaCl和CaCl2质量分数分别为10%和5%的条件下,PAM-AMPS/Fe_(3)O_(4)减阻剂黏度保留率分别为69%和53%,表现出了较强的耐盐性;同时,该减阻剂在剪切速率1000 s^(-1)条件下剪切3600、7200 s后的黏度回复率分别为100%和94%,表现出良好的耐剪切性。

In this study,a PAM-AMPS/Fe_(3)O_(4) nano drag reducing agent was synthesized by grafting acrylamide/2-acrylamido-2-methylpropane sulfonic acid(AM/AMPS)copolymer onto nano Fe_(3)O_(4),the shear dilution of PAM-AMPS/Fe_(3)O_(4) drag reducing agent was studied by dynamic rheometer,and the influence law of nano-Fe_(3)O_(4),salt content and shearing action on their rheological behavior was also analyzed.The results show that the particle size of PAM-AMPS/Fe_(3)O_(4) nano drag reducing agent is 100—500 nm,and the viscosity-average molecular weight is 4.99×10^(6) g/mol.At 30℃,PAM-AMPS/Fe_(3)O_(4) drag reducing agent exhibits significant shear dilution characteristics when the shear rate is greater than 0.3 s^(-1).The drag reducing agent has a more complex microstructure,and its supercritical mass fraction is 0.035%.Compared with the blank polymer,it shows better viscosity enhancing ability and viscoelasticity behavior.As AMPS contains temperature and salt-tolerant groups,when the mass fraction of NaCl and CaCl 2 is 10%and 5%,the viscosity retention rates of PAM-AMPS/Fe_(3)O_(4) drag reducing agent can reach 69%and 53%respectively,showing a strong salt tolerance.Meanwhile,the viscosity recovery rates of the drag reducing agent after shearing for 3600 s and 7200 s at a shear rate of 1000 s^(-1) can reach 100%and 94%,respectively,demonstrating a good shear resistance.