超临界CO_2方法制备的聚丙烯腈的表面特性

Surface Properties of Polyacrylonitrile (PAN) Produced by the Supercritical CO_2

根据Washburn浸渍理论(Penetrationtheory)和vanOss Good Chaudhury的组合理论及应用柱状灯芯技术(Columnwickingtechnique),测试了用超临界CO2方法制备的不同分子量聚丙烯腈(PAN)的表面特性。结果显示,PAN的分子量影响其表面性能。与一般聚合物的表面能随分子量增大而增大的规律不同,超临界方法制备的聚丙烯腈(PAN)的表面能随着分子量的增大而降低,但其Lifshitz vanderWaals力却随分子量的增大而增大。与常规方法生产的PAN的表面性能比较,超临界方法可能使PAN的极性减少。

Applying the Washburn penetration theory, the van OssGoodChaudhury combining rules and the column wicking technique, the surface free energy and related components of polylacrylonitrile (PAN) produced by the supercritical CO2 were estimated. Results show that its molecular weight is a factor to influence the surface properties of PAN. However, it is found that the surface free energy of the PAN prepared in supercritical CO2 decreases with the increase of the molecular weight, which obviously contrary to the most other polymers. In addition, it seems that the polarity of the polymer synthesized at the supercritical condition is weaker as comparing to that of the PAN from a conventional method.