聚氨酯改性烯丙基环氧树脂的研究

采用异氰酸酯基(-NCO)封端的聚丙二醇(PPG2000)预聚体(PUR)与烯丙基环氧树脂(DADGEBA)中的-OH反应将聚氨酯柔性链段引入环氧树脂结构中,使用傅里叶红外光谱仪(FTIR)对其结构进行表征,用旋转黏度计测定其粘温变化,平板小刀法测其与4,4’-二氨基二苯甲烷(DDM)固化凝胶时间,差示扫描量热仪(DSC)对其固化物玻璃化转变温度(Tg)进行了研究。考察了质量比m(DADGEBA):m(PU)对PU改性DADGEBA力学性能和热性能的影响。实验结果表明,PU链段可以改善DADGEBA的韧性,并且两者相容性较好,同时接枝并不影响环氧树脂中的烯丙基双键和环氧基团;当质量比m(DADGEBA):m(PU)=100:10时,粘流活化能为67.9kJ/mol,与DDM固化表观活化能为50.5kJ/mol,并且固化物韧性和强度同时提高,耐热性较好。

Study on diallyl-bearing epoxy resin modified by polyurethane

The epoxy resin modified by polyurethanes(PU)was obtained under certain conditions by the reaction between isocyanate-terminated polypropylene glycol(PPG2000)and hydroxyl of Diglycidyl ether of 4,4-diallyl-bisphenol-A(DADGEBA)and its structure was characterized by FTIR,the character of viscosity-temperature of the modified resin was tested by a rotary viscosimeter,the gel time of the resin cured using DDM was obtained by plate-knife method,and differential scanning calorimetry(DSC)was used to study the glass transition temperature.Meanwhile the influences of mass ratio of DADGEBA and PU on properties of DADGEBA modified by PU were investigated.Experimental result indicated that the hydroxyl of DADGEBA and the isocyanate of PU prepolymer were crosslinked to modify the resin,and the PU grafted do not influence the unsaturated double bonds in DADGEBA.When mass ratio of m(DADGEBA):m(PU)was 100:10,the activation energy for viscous-fluid was 67.9KJ/mol,apparent activation energy of the resin cured by DDM was 50.5KJ/mol,and the toughness and strength of modified EP were optimal.