Studied on the Interaction of a Fluorocarbon and Hydrocarbon Hydrophobically Co-modified thickener with a Nonionic Surfactant

摘要

Derivatives of poly(acrylic acid) hydrophobically modified with hydrocarbon group (PH), fluorocarbon group (PF) and both of them (PHF) were synthesized and the associations of these copolymers with HC nonionic surfactant Np7.5 were investigated by means of rheological measurements. Although poor compatibility was found between FC hydrophobiles of PF and HC moiety of Np7.5 due to the lipophobicity of FC groups, the rheological properties of PHF are close to PH in the association with Np7.5. Similar to Winnik's mixed model, microdomains formed in the system of PHF/Np7.5 also consist of both HC and FC groups. The hybrid structure of FC and HC groups on the polysoap backbone was proposed to improve the miscibility between FC and HC groups. Whether Np7.5 associate s with only HC groups or both HC and FC groups in the interaction with PHF is further investigated. Rheological measurements indicate that morphological changes appear in PHF/Np7.5. When the concentration of Np7.5 reaches 0. 1wt% in 0.30wt% polymer solution, physical network junctions become greatly stabili/ed. We speculate that Np7.5 associates with both HC and FC groups and in this case HC and FC groups arc really miscible. In other cases, PHF behaves like PH and Np7.5 only associates with HC groups of PHF. Although FC groups are also associated in the hydrophobia microdomain, they arc pseudo-miscible only with HC groups.