磷酰胆碱基共聚物的合成及其稳定聚合物涂层表面的构筑

Preparation of Phosphorylcholine Based Copolymer and Its Polymer Coating with Improved Surface Stability

设计并合成了侧基分别含有磷酰胆碱(PC)亲水基团和胆固醇(Chol)疏水基团的两亲性二元无规共聚物PMC,用其对疏水基材聚丙烯中空纤维膜(PPHF)表面进行亲水改性,并以疏水基团为十二烷基柔性烷烃的磷酰胆碱基两亲性二元无规共聚物PML为参照聚合物,研究了聚合物涂层加热处理及空气中久置后涂层表面的稳定性.用1H-NMR和DSC对二元随机共聚物PMC和PML的结构和熔点(Tm)进行测定,用ARTR和XPS表征磷酰胆碱基共聚物构筑的两性离子表面的化学成分,用接触角研究其表面亲水性,并用水的动态接触角(DCA)评价涂层表面功能基团重新迁移取向的能力.结果发现,所得二元无规共聚物PMC和PML中组成与投料比相近且PMC的熔点Tm(190.5℃)远高于PML的(90.3℃);与PML改性PPHF表面相比,PMC-PPHF表面亲水性提高,而且经100℃高温处理2 h和空气中放置8个月后,接触角和表面磷元素相对含量基本不发生变化,说明表面功能基团基本不发生重新迁移取向,表面结构稳定性好.

An amiphiphilic phosphorylcholine based copolymer （PMC） bearing hydrophilic phosphorylcholine （PC） and hydrophobic cholesteryl （Chol） side groups was designed and prepared by free radical polymerization. It was used to modify the hydrophilic feature of the surface of microporous polypropylene hollow fiber （PPHF） membrane using another phosphorylcholine based copolymer PML （containing n-dodecyl hydrophobic side groups） as control.1H-NMR and DSC were used to determine the chemical structure of the obtained phosphorylcholine based copolymer. The surface chemical composition was measured by X-ray photoelectron spectroscopy （XPS） and attenuated total reflectance infrared spectroscopy （ATR-IR）. The hydrophilicity of the modified membranes and reorganization behavior of surface functional groups were characterized by static and dynamic contact angle, respectively. The results showed that the ratio of the monomer units in the amphiphilic random copolymers were similar to the ratios in feed. The melting temperature of PMC （190.5 ℃） was much higher than that of PML （90.3 ℃）. Compared with the virgin PPHF membrane surface, the static water contact angle of PMC-PPHF was greatly decreased from 117° to 44°. Moreover, when PMC-PPHF was heated at 100 ℃ for 2 h and placed in air at room temperature for 8 months, respectively, the water contact angle and the relative amount of P element almost did not change, which indicated the improved surface stability in comparison with PML-PPHF.