聚氨酯改性TDE-85/MeTHPA环氧树脂体系的结构表征

Structural identification of PU-modified TDE-85/MeTHPA epoxy resin

选用聚醚二元醇(PPG)和甲苯二异氰酸酯(TDI)为原料,合成聚醚型聚氨酯预聚体。采用该聚氨酯预聚体(PUP)、扩链剂、交联剂对TDE-85/甲基四氢邻苯二甲酸酐(MeTHPA)环氧树脂进行改性,通过扫描电镜与红外光谱分析,探讨聚氨酯(PU)改性环氧树脂(EP)体系的结构特征。结果表明:TDE-85与MeTHPA之间发生固化反应,形成环氧聚合物网络Ⅰ;1,4-丁二醇(1,4-BDO)及三羟甲基丙烷(TMP)与PU预聚体之间发生了扩链、交联反应,形成聚氨酯聚合物Ⅱ;PU改性TDE-85/MeTHPA树脂为非均相结构,PU含量是影响PU/EP材料两相相容性和相区尺寸的主要因素;当添加的PUP质量分数为15%时,PU改性TDE-85/MeTHPA体系具有互穿聚合物网络结构特征。

PU-modified TDE-85/MeTHPA epoxy resin was prepared with chain-extended reagent （1,4-BDO）, crosslink agent （TMP）, and polyurethane prepolymer （formulated by polypropylene glycol （PPG） and 2,4-toluene diisocyanate （TDI）. The structure characters of this system were discussed by SEM and IR. The results indicate that polymer network Ⅰ was obtained by the curing reaction between TDE-85 and MeTHPA, and polymer network Ⅱ was obtained by chain-extended and cross linking reaction of 1,4-BDO, TMP and polyurethane prepolymer （PUP）. Meanwhile the PU-modified TDE-85/MeTHPA resins have heterogeneous structure. The content of PU plays a main role in the compatibility and size of phases of modified materials. An optimum mass fraction of PUP （15%） is determined that shows obvious characters of interpenetrating polymers network （IPN） structure.