【摘要】 <正> 多嵌段聚醚型聚氨酯(SPEU)以其优良的力学性能和良好的血液相容性,被公认为一种重要的心血管医用高分子材料。现在一般认为,高分子生物材料的抗凝血性能主要取决于材料表层的组成和结构,但以前的工作多集中于新材料的开发研究,很少涉及到动态形变对SPEU的表层结构及其血液相容性的影响。更多还原

【Abstract】 The changes of surface layers’ microphase separation structure of segmented polyether urethane （SPEU）based on 4, 4′-diphenylmethane diisocyanate, polyoxytetramethylene glycol and chain extender （ethylene diamine） during fatigue process have been studied by means of FT-ATR-IR spectrometry.Experimental results show that the peak of hydrogen bonded urea carbonyts shifts approximately 1.15 cm^-1 （average of 4 tests） to higher frequency after fatigue process.This is probably due to the fatigue behavior of SPEU with decreasing the ordered hard segments and causing dispersion of some soft segments in the hard domains.This allows the polyether oxygens to compete with urea carbonyls for the urea NH groups and results in a mixed state of less threc-dimensional and more conventional hydrogen bonds coexisting in SPEU.In order to calculate the content of hydrogen bonded urethane carbonyls （X_B%） ,resolution curve program was carried out in the range of 1685—1750 cm^-1. The X_B （%） of SPEU before and after fatigue process were averagely 44.75 and 42.16% respectively.This decrease of X_B percent may be attributed to the breakup of hard domains in SPEU by fatigue process。更多还原