含羧基乳胶粒子体系的流变性质与碱增稠机理

Rheological Property and Alkali-thickening Mechanism of the Latex System Containing Carboxyl Groups

采用流变学实验数据分析乳胶粒子体系的致粘机理 .认为普通硬球型乳胶粒子体系的致粘机理与聚合物链段的亲水性有关 .聚合物链段的亲水性越强 ,普通硬球型乳胶粒子体系的粘度越大 .在酸性介质中 ,含羧基乳胶粒子体系的致粘机理与普通硬球型乳胶粒子体系一致 .但在碱性介质中 ,含羧基乳胶粒子体系呈现碱增稠现象 ,认为这种碱增稠现象是由粒子间氢键形成的桥式结构所致 ,这一观点与早期的“乳胶粒的溶胀乃至溶解”

On the basis of rheological experimental results, we analyzed the rheological mechanism of the latex system. The viscosity mechanism of a common hard-sphere latex particle system is considered to be related to the hydrophilicity of the polymer chain. The stronger the hydrophilicity is, the higher the viscosity is. In the acid medium, the viscosity mechanism of the system of latex particles containing carboxyl is the same with that of the common hard sphere latex system. But in the alkali medium, the system of latex containing carboxyl appears an alkali-thickening phenomenon. So the alkali-thickening mechanism has been considered to be attributed to the bridge-structure formed from the hydrogen bonds of the particles. This opinion is different from the early deduction 'from the swell to the solution of the latex particle'.