CVD聚合制备聚(羟甲基对亚苯基二亚甲基)及其性能的研究

Studies on poly (hydroxymethyl-p-xylylene-co-p-xylylene) prepared by CVD polymerization

用化学气相沉积(CVD)聚合法制备了聚(羟甲基对亚苯基二亚甲基)(PPX-HM)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-HM膜具有优异的耐溶剂性和抗化学氧化性能。对PPX-HM膜热性能的研究表明羟甲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,热降解起始温度比聚对亚苯基二亚甲基(PPX)低,但主链降解温度比PPX反而高出约50℃。此外,羟甲基的引入使得膜的亲水性能大幅度提高,水汽透过性能也有所提高。

Poly（p-xylylene） （PPX） prepared by chemical vapor deposition （CVD） polymerization shows promising features like absolute conformance to substrate topology, pinhole-free coverage even in very thin films, the ability to penetrate and cover complex geometries, and extraordinarily high chemical inertness and purity compared to common polymer coating. However, the exploitation of （2,2） paracyclophanes for generating functionalized surfaces is interesting. The functional groups may be useful for further modifications. Poly（hydroxymethyl-p-xylylene-co-p-xylylene） （PPX-HM） 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-HM 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-HM membranes. It is found that the initial degradation temperature and Tg of PPX-HM membranes are reduced with the introduction of hydroxymethyl group as side groups, while the degradation temperature of the main chain of PPX-HM is higher than that of PPX. With the introduction of hydroxymethyl, the polymer becomes amorphous. The softness and the dynamic mechanical damping properties of PPX-HM membranes are improved. The hydrophilicity and vapor permeability of PPX-HM membranes are also improved.