粘度法研究疏水改性聚丙烯酸与Np7.5的相互作用

Viscometric Study on the Interaction Between Hydrophobically Modified Poly(acrylic acid) and Np7.5

研究了氟碳基团改性和氟碳、碳氢基团同时改性的聚丙烯酸 (HM -PAA)以及参比聚合物 (PAA)与非离子表面活性剂Np7.5分别在稀溶液和亚浓溶液下的相互作用对特性粘数和Brookfield表观粘度的影响。结果表明 ,PAA与Np7.5无明显作用 ,而HM -PAA在Np7.5达到一定浓度后 ,由于Np7.5参与了疏水缔合 ,特性粘数和表观粘度发生了明显变化。稀溶液中 ,氟碳基团较多的聚合物出现了链构象的伸展。亚浓溶液中 ,疏水改性聚合物的粘度都有先上升后下降的变化 ,但氟碳含量较多的变化更强烈。

The effects of the interactions of PAA unmodified and hydrophobically modified by fluorocarbon group as well as both fluorocarbon group and hydrocarbon group with nonionic surfactant Np7.5 on intrinsic viscosity in dilute solution and Brookfield viscosity in semidilute solution were investigated. No apparent interactions were found for unmodified PAA. For HM-PAA, however, both intrinsic and apparent viscosity were significantly changed due to hydrophobic association when Np7.5 reaching a certain value. In dilute solution, the extension of the conformation occurs for the PAA modified by more fluorocarbon groups. In semidilute solution, the PAA modified by more fluorocarbon groups also shows a more drastic increase and decrease in solution viscosity compared to the less modified.