提高二氨基二苯砜(DDS)固化环氧树脂体系的反应活性,降低反应温度、提高反应速率,具有重要的研究意义和实用价值。本研究以聚酯(PEGA1000,2000,PNGA1000,2000)、甲苯-2,4-二异氰酸酯(TDI)、二甲胺为原料合成了含有聚酯型柔性间隔基的扩链脲U-PEGA1000,2000,U-PNGA1000,2000,用其改性环氧树脂E-51/DDS体系,采用DSC系统考察了改性体系的固化反应活性。结果表明,改性体系固化反应活性明显提高,固化反应表观活化能降低,固化反应峰顶温度从230℃降至170℃,固化反应的表观活化能由67.74kJ/mol降至47.80kJ/mol。
A series of novel reactive chain-extended ureas (U-PEGAIooo, 2000 or U-PNGA1000, 2000) containing flexible spacer were synthesized to modify the curing system composed of epoxy resin (E-51) and diamino diphenyl sulfone (DDS). The curing behavior of the modified E-51/DDS system was systematically investigated by differential scanning calorimeter (DSC). The results revealed that the curing reactivity of the epoxy system was greatly enhanced with the addition of the modifier, the curing reaction peak temperature decreased 55-60℃, and the apparent activation energy of curing reaction was reduced from 67.74kJ/mol to about 50kJ/mol.