表面接枝二苯甲酮光活性聚合物及光化学固定大分子的研究

采用两步法表面接枝聚合技术，通过热活化脱除偶合半嚬哪醇（BPOH）基团而产生表面自由基，引发二苯甲酮（BP）光活性单体4 甲基丙烯酸二苯甲酮酯（BPMA）与4,4′ 对甲基丙烯酸二苯甲酮酯（DMABP）在聚丙烯膜(CPP)表面进行接枝聚合，将大量光活性BP结构单元引入到膜表面，进一步在UV光辐照下将疏水聚合物聚苯乙烯（PSt）、亲水聚合物聚乙二醇（PEG）及生物大分子牛血清白蛋白（BSA）偶合固定在膜表面。考察了光照时间及引发剂BP浓度对偶合BPOH基团的影响，研究了热引发光活性BP单体表面接枝聚合温度、单体组成对接枝效果的影响，采用UV-Vis光谱、XPS分析及表面水接触角测定表征了表面接枝量及性能变化。结果表明，提高反应温度有利于接枝反应，DMABP反应活性要高于BPMA；固定PSt后，接触角明显增加，表面疏水性增强，固定PEG和BSA后，接触角下降10°~20°，表面亲水性明显提高。

Studies on surface grafting of a benzophenone photoactive polymer and attachment of macromolecules by a photochemical method

Benzophenone(BP) units have been incorporated onto the surface of a polypropylene(PP) film by a two-step photografting polymerization of photoactive monomers containing BP moieties,4-benzophenone methacrylate(BPMA) and 4,4′-dimethacrylate benzophenone(DMABP).Semipinacol groups were coupled on the surface in the first step,and then cleaved by heating in the second step to generate macro-radicals on the surface to begin the grafting polymerization.The effects of varying the radiation time and content of BP used in the first step were examined.The effects of varying the reaction temperature and composition of the mixed monomers in the second step were also investigated.UV-visible spectroscopy,XPS and contact angle measurements were employed to follow the grafting process and modification of the surface.Furthermore,hydrophobic polystyrene,and hydrophilic polyethylene glycol(PEG) and bovine serum albumin(BSA) were attached onto the surface by photochemical reaction with the BP units,resulting in an increase in the hydrophobic or hydrophilic character of the surface,respectively.