密封圈用聚氨酯弹性体的合成及其性能研究

摘要

以相对分子质量均为1000的低聚物二醇为软段与2,4-甲苯二异氰酸酯(T-100)合成预聚体,用3,3′-二氯-4,4′-二苯基甲烷二胺(MOCA)固化制备聚氨酯弹性体,研究了低聚物二醇的种类、扩链系数、纳米二氧化硅的添加量以及硬段含量对弹性体性能的影响.结果表明,以聚己二酸乙二醇酯二醇(PEA)作为软段、扩链系数为0.90、纳米二氧化硅添加质量分数为0.4%、硬段质量分数为32.79%(即NCO质量分数为5.6%)时,所制得的聚氨酯弹性体具有优异的耐油性能及综合力学性能,成本较低.%Urethane prepolymers were synthesized by 2,4-toluene diisocyanate( TDI) and a variety of oligomer diols with Mn=1000. A serial of polyurethane elastomers were prepared by the prepolymers chain-extended with 4, 4′-methylene-bis(2-chloroaniline) (MOCA). The effects of oligomer diol type, chain extension coefficient, nano-silica content and hard segment content on the mechanical properties of polyurethane elastomers were investigated. The results showed that, the polyurethane elastomers had excellent oil resistance and comprehensive mechanical properties when poly( ethylene adipate) diol was used as soft segment, the chain extension coefficient was 0. 90, mass fraction of nano-silica was 0. 4% and the hard segment content was 32. 79% ( with NCO content of 5. 6%) .