聚氨酯表面构建磺铵两性离子结构及其抗血小板粘附性的研究

通过己二异氰酸酯(HDI)在聚醚氨酯(PU)表面构建磺铵两性离子结构,以改善其不凝血性能,首先用HDI活化PU表面,生成PU-NCO衍生物;然后通过N,N-二甲基乙醇胺(DMEEA)中的-OH和PU表面的-NCO反应生成PU-N(CH₃)₂;最后用丙磺酸内酯(PS)进行开环.生成磺铵两性离子结构,用ATR-IR表征了各步反应,对构建前后材料的抗血小板粘附性能进行了比较,结果表明,磺铵两性离子结构具有优异的抗血小板粘附性.

Construction of Sulfoammonium Zwitterionic Structure onto Surface of Polyurethane by Hexamethylene Diisocyanate (HDI) Spacer for Improving Blood Compatibility

At the molecular level, it is believed that polymers containing zwitterionic structure should be more compatible with blood. The films of polyether-urethane were constructed with sulfoammonium zwitterionic structure by a three-step procedure. In the first step, the film surfaces were treated with hexam-ethylene diisocyanate(HDI) in toluene at 50 'C in the presence of dibutyltin dilaurate(DBTDL) as a catalyst. The extent of the reaction was measured by ATR-IR spectra. A maximum number of NCO groups were obtained in about 90 min reaction. In the second step, the hydroxy groups of N, N-dimethylethylethanolamine (DMEEA) were allowed to react in toluene with surface bound isocyanate groups. In the third step, sulfoammonium zwitterionic structures were constructed onto the surface through the ring-opening reaction between tertiary amine constructed by the second step and 1,3-propane-sultone(PS). The surface was characterized by ATR-IR and XPS, and as anticipated, the sulfoammonium structure was constructed on the PU films. The platelet adhesion test revealed that films attached to sulfoammonium zwitterionic structure showed an excellent anti-platelet adhesion. These good results are due to the interfacial sulfoammonium zwitterionic structure.