化学气相沉积聚合制备羧基取代聚对亚苯基二亚甲基及其性能研究

用化学气相沉积(CVD)聚合法制备了羧基取代聚对亚苯基二亚甲基(PPX-carb)膜,采用FTIR和元素分析的方法证实了其化学结构.对膜溶解性和抗化学氧化性能的研究表明PPX-carb膜仍具有优异的耐溶剂性和抗化学氧化性能.对PPX-carb膜热性能的研究表明羧基的引入使得膜的玻璃化转变温度降低,室温柔性增强,动态力学阻尼性能增大,与聚对亚苯基二亚甲基(PPX)相比引入了羧基的PPX-carb热稳定性有所下降,热降解起始温度比PPX低,但主链降解温度比PPX反而高出约80℃.此外,羧基的引入使得膜的亲水性能大幅度提高,水汽渗透性能也有所提高.

CHEMICAL VAPOR DEPOSITION POLYMERIZATION AND PROPERTIES OF POLY(CARBOXYL-p-XYLYLENE-co-p-XYLYLENE)

Poly(p-xylylene)(PPX) prepared by chemical vapor deposition (CVD) polymerization shows promising features like absolute conformation to substrate topology,pinhole-free coverage even in ultrathin films,the ability to penetrate and cover complex geometries,and extraordinarily high chemical inertness and purity compared to common polymer coatings.However,the exploitation of 2.2paracyclophanes for generating functionalized surfaces is interesting.The functional groups may be useful for further modifications.Poly(carboxyl-p-xylylene-co-p-xylylene)(PPX-carb) was prepared by CVD polymerization in present work.The chemical structure of the resulted polymer was confirmed by FTIR and elemental analysis.It is indicated that PPX-carb membrane has good solvent resistant and high chemical oxidation resistant.Thermogravimetric analysis(TGA),differential scanning calorimetry(DSC),and dynamic mechanical analysis(DMA) were used to study the thermal properties of PPX-carb membranes.It is found that the initial degradation temperature and T_g of PPX-carb membranes are reduced with the introduction of carboxyl group as side groups,while the degradation temperature of the main chain of PPX-carb is higher than that of PPX.With the introduction of carboxyl,the polymer becomes amorphous,and the softness as well as the dynamic mechanical damping properties of PPX-carb are improved.The hydrophilicity and vapor permeability of PPX-carb membranes are also improved.