【摘要】 以二苯基甲烷二异氰酸酯(MDI)和聚四氢呋喃醚二醇(PTMG)合成预聚体,用2-甲基-2-UPy(2-脲-4[H]-嘧啶酮)基-1,3-丙二醇为扩链剂制备了一系列侧链含UPy的聚氨酯。利用FT-IR、1 H-NMR、DMA和力学性能测试等手段对该聚氨酯的结构和性能进行了表征。结果表明:该聚氨酯的力学性能与不含UPy基团的聚氨酯相比有较大的提升;UPy的四重氢键效应形成的物理交联网络结构,使该聚氨酯的玻璃化转变温度随UPy含量的增加向高温方向移动,损耗角正切(tanδ)峰减弱;在宽频的频率场中,随着UPy含量增加,tanδ峰向低频移动,峰强减弱,储能模量增大。更多还原

【Abstract】 Polyurethanes with the ureidopyrimidone side groud were synthesized from 4,4′-diphenylmethane diisocyanate and polytetramethylene glycol(PTMG),incorporating 2-methyl-2-UPy(2-ureido-4-pyrimidone)-1,3-propanediol as chain extender,of which the structure was confirmed by FT-IR and 1H-NMR.Results of tensile test demonstrated that the mechanical properties of polyurethanes were greatly improved by introducing UPy group in the side chain.In dynamic mechanical thermal analysis,with the increasing of the content of UPy,the glass transition temperature increased correspondingly,whereas the peak value of tan δ decreased.In the wide frequency field,with the increasing of the content of UPy,the influence of frequency to peak value of tan δ and storage modulus(E′) would lead the movement of peak value of tan δ to low frequency,peak intensity decreased,tan δ and E′ increased.更多还原