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以α,ω-双(γ-羟丙基)聚二甲基硅氧烷(BHPDMS)和聚氧四甲基二醇(PHMO)混合大二醇为软链段;以1,4-丁二醇(BDO)为主要扩链剂,1,3-双(4-羟丁基)-1,1,3,3-四甲基二硅氧烷(BHTD)为次级扩链剂,所有试样中硬链段均由4,4’-二苯基甲烷二异氰酸酯(MDI)和混合扩链剂所构成,且w(硬链段)=40%;采用两步溶液聚合法制备混合大二醇基芳香聚氨酯(PU)弹性体。通过力学性能测试、差示扫描量热法(DSC)和动力学热分析法(DMTA),研究了混合扩链剂中n(BDO)/n(BHTD)比值对该PU弹性体性能的影响。结果表明,当n(BDO):n(BHTD)=3:2时,所得PU弹性体具有优异的综合性能;引入BHTD扩链剂后,破坏了硬链段的有序性。
The macrocyclic diols were mixed with α, ω-bis (γ-hydroxypropyl) polydimethylsiloxane (BHPDMS) and polyoxytetramethylene glycol (PHMO) Alcohol (BDO) as the main chain extender, 1,3-bis (4-hydroxybutyl) -1,1,3,3-tetramethyldisiloxane (BHTD) The middle hard segment was composed of 4,4’-diphenylmethane diisocyanate (MDI) and mixed chain extender, and w (hard segment) = 40%. The two-step solution polymerization Alcohol based aromatic polyurethane (PU) elastomer. The effect of n (BDO) / n (BHTD) ratio on the properties of PU elastomer was studied by mechanical property test, differential scanning calorimetry (DSC) and dynamic thermal analysis (DMTA) The results showed that the obtained PU elastomers had excellent overall properties when n (BDO): n (BHTD) = 3: 2. The introduction of BHTD chain extender destroyed the ordering of hard segments.