紫外光引发PNIPAAm及其共聚物改性PS表面研究

摘要

Polystyrene (PS) surface was modified by UV-grafting of PNIPAAm or copoly-mer of NIPAAm and St with better compatibility to PS. The results of FTIR and contact angle to water droplet show that PNIPAAm or P(NIPAAm/St) copolymer can exist tightly on the surface of PS and turn the PS surface from hydrophobic to hydrophilic along with thermo-sensitivity. PNIPAAm grafted PS exhibites obvious thermosensitive characteristic meanwhile it's the contact angle to water droplet changes from 44° at 23 'C to 68° at 40 "C. St in P(NIPAAm/St) copolymer helps improving the PS compatibility, transparence and stability of the grafted polymer but leads to the depress of thermosensitivity.%采用紫外光引发聚合将聚N-异丙基丙烯酰胺(PNIPAAm)接枝在聚苯乙烯(PS)表面或在PS表面形成与之相容性较好的NIPAAm与苯乙烯(St)共聚物即P(NIPAAm/St)共聚物层,以改性PS的表面性质.红外光谱分析(FTIR)和表面接触角测试结果表明,PNIPAAm或P(NIPAAm/St)共聚物可以在PS表面稳定存在,使PS表面由疏水性变为亲水性,且具有一定的温敏性.单纯PNIPAAm接枝PS改性层的温敏性更为明显,当温度由23℃增加到40℃时,PNIPAAm改性PS表面与水的接触角由44°左右增加到68°左右.P(NIPAAm/St)共聚物中的St有利于提高改性层与PS的相容性、透明性及稳定性,但其温敏性下降.