等离子体处理云母粉对其表面特性及对其与聚合物界面特性的影响

THE EFFECT OF PLASMA TREATMENT OF MICA POWDER ON ITS SURFACE CHARACTERISTICS AND INTERFACE BEHAVIOR WITH LINEAR MACROMOLECULES

采用等离子体方法处理填料及增强体表面,是提高填料及增强体与聚合物基体的粘合性、改善复合材料性能的一个新的有效途径。目前研究工作集中于处理条件与复合体系宏观性能的关系上,对处理前后填料表面性质以及填料与聚合物界而性质变化的探讨却很少。而只有了解上述变化才能从本质上认识处理条件与复合体系宏观性能的关系。本文首次对云母粉进行丁醛等离子体处理,测定了处理前后液体在云母粉表面的接触角。

In this work mica powder was treated with n-butyl aldehyde plasma of radio frequency. Then the apparent contact angle of different liquids on the powder was determined by measuring the penetration rate of the liquid through the packed powder. The surface tension of mica powder and interface tension between the powder and typical linear macromolecules were calculated from the data of contact angle obtained under Fowkes' assumption. Rationalized conclusions were as follows: (ⅰ) For polar liquids,wetting of treated mica is more difficult than the untreated one and for nonpolar liquids no difference has been observed.(ⅱ)The surface tension of mica powder drops from 41.34(N·m^(-1)·10^(-3)) to 31.51 after 5 min plasma treatment and to 25.59(N·m^(-1)·10^(-3)) after 30 min plasma treatment. (ⅲ)The polar component of interface tension between the mica powder and any linear macromolecule monotonically decreases with the time of plasma treating. However, the whole interface tension changes after plasma treatment, depending on the polymer used.