聚碳酸酯聚氨酯的结构及性能

引言 聚氨酯由于具有很好的生物相容性和血液相容性,加上优异的机械强度和耐挠屈性1-2],很早就作为医用材料受到人们的重视.过去很多研究工作集中在对聚醚型聚氨酯的合成方面3-5],但大量研究表明,聚醚聚氨酯容易在血液中巨嗜细胞所产生氧自由基的作用下氧化降解,导致生理条件下的应力开裂.与聚醚聚氨酯相比,聚碳酸酯聚氨酯(PCNU)在小直径血管和内部血管治疗中,显示出了更好的向内生长能力,且有较低的水透过率,后者对永久人工心脏的制造有着极为重要的意义.

Structure and performance of polycarbonate urethane

Polycarbonate urethane was synthesized from polycarbonate diol(PCN),4,4′-methylene diphenyl diisocyanate and 1,4-bytanediol by the melting one-shot method.The thermal behavior and microphase separation of the polymer were characterized with DSC and TGA.The distance between microphases was estimated from the data of SAXS.Tensile test was used to analyze the effects of different M_n of PCN and content of soft segment on mechanical properties.The results showed that the polymer had partial microphase separation structure, and this structure was less obvious with the increase of the content of soft segment.There were two types of micro-domains in the continuous phase of polycarbonate，the micro-domain formed with urethane and the micro-domain of polycarbonate crystallization itself.There were two obvious stages in its thermal decomposition on which the effect of the content of soft segment was not obvious.With the increase of the content of PCN, the Young’s Modulus decreased and the elongation at break increased.The as-synthesized polycarbonate urethanes(PCNU)showed a maximum tensile strength of 80 MPa.At the same time, elongation at break was more than 400%.