PAPP/PPG组合多元醇对刚性聚氨酯力学性能的影响

Effect of polyol composed with PAPP and PPG on the mechanical properties of rigid polyurethane

以多亚甲基多苯基异氰酸酯（PMDI）为硬段，苯酐聚酯多元醇（PAPP）和聚丙二醇（PPG400）的组合多元醇为软段，制得双组分聚氨酯树脂。通过万能材料试验机、简支梁冲击试验机研究了PAPP的含量及类型对聚氨酯力学性能的影响。结果表明：随着PAPP含量的增加，聚氨酯的拉伸强度和冲击强度先增大后减小。PAPP官能度为3的聚氨酯的拉伸强度大于PAPP官能度为2和4的聚氨酯，但冲击强度小于后者。随着PAPP分子质量的增加，拉伸强度先不变后减小，冲击强度逐渐增大。在PAPP的质量分数为30％时，PAPP分子质量为400，官能度为3的聚氨酯力学性能最好，此时，拉伸强度和弹性模量分别为68．3MPa和2．86GPa，冲击强度为71．3kJ／m^2。

The two-component polyurethane resins were prepared by using polymethylene polyphenyl isocyanate （PMDI） as hard segment, polyol composed with phthalie anhydride polyester polyol （PAPP） and polypropylene glycol （PPG400） as soft segment.The effect of PAPP content and type on the mechanical properties of polyurethane were investigated by universal testing machine and charpy impact test machine . The results indicated that with the increasing of PAPP content, the tensile strength and impact strength were firstly increased and then decreased.The tensile strength of polyurethane with PAPP functionality of 3 was better than that of 2 and 4, but impact toughness was in contrast. With the increasing of the molecular weight of PAPP, the tensile strength firstly was stable then decreased and impact strength was increased gradually. When the content of PAPP （Mn=400, n=3 ）was 30%, the mechanical properties of the resin was best and the tensile strength and elastic modulus was 68.3 MPa and 2.86 GPa, respectively.The impact strength was 71.3 kJ/m^2.