环糊精用于测定疏水缔合聚合物特性黏数

Determination of Intrinsic Viscosity of Hydrophobic Association Polymer by the Usage of Cyclodextrin

摘要:

由于分子内和分子间疏水缔合作用随疏水缔合聚合物溶液浓度变化而不断变化，按照国家标准(GB12005.1-89)测得的特性黏数并不能准确反映疏水缔合聚合物的单链性质。利用环糊精疏水空腔对疏水基团的包合作用，采用毛细管法测定了疏水缔合聚合物在不同环糊精/疏水基团物质的量之比的（CD:[H]）溶液中的特性黏数，并分别通过一点法和外推法计算了特性黏数。两种方法计算得到的结果相互吻合。随CD:[H]增大，疏水缔合聚合物的特性黏数先增加后稳定；Huggins参数，先降低后逐渐平稳。对比实验表明，环糊精通过对疏水基团的包合作用改变疏水缔合聚合物的特性黏数，过量的环糊精对聚合物的特性黏数没有明显影响

Abstract:

Due to the change of the intra- and intermolecular hydrophobic association with the concentration of hydrophobic association polymer solution, the result of intrinsic viscosity for the hydrophobic association polymer tested according to the method in the national standard (GB12005.1-89), could not accurately reflect the single chain character. In this study, based on the inclusion of cyclodextrin and hydrophobes, the intrinsic viscosities of hydrophobic association polymer solution with various molar ratios of cyclodextrin and hydrophobes (CD: [H]) were measured by capillary method and calculated by one point and extrapolation method respectively. The results obtained by the two methods are consistent with each other. With the increase of CD: [H], the intrinsic viscosity of the hydrophobic associating polymer increased and then stabilized, and the Flory-Huggins interaction parameter decreased and then tended to plateau. The results of comparison experiment show that the intrinsic viscosities of the hydrophobic associating polymer change by the inclusion of cyclodextrin with hydrophobes, and the excess cyclodextrin has little effect on the conformation of polymer backbone. Key words：intrinsic viscosity; hydrophobic association polymer; cyclodextrin; polyelectrolyte effect