新型环氧氨酯增韧改性环氧树脂的研究

Study on Epoxy Resin Modified by Novel Epoxyurethane

以环氧树脂E-44为树脂基体,自制的新型环氧氨酯为增韧改性剂,选用自行合成的丙烯酸乙酯改性二乙烯三胺固化剂,固化不同组成比的环氧氨酯/E-44共混物,测定了共混固化材料的冲击强度、剪切强度及动态力学性能。结果表明,随着环氧氨酯含量的增加,冲击强度逐渐增加,剪切强度先逐渐增加而后减小,当环氧氨酯含量达50%时出现极大值;随着环氧氨酯相对分子质量的增大,剪切强度变小,冲击强度先增而后减;与环氧树脂(E-44)-二乙烯三胺固化体系相比,共混组成比(质量比)为50:50时,该体系的增韧效果非常明显,把环氧树脂的冲击强度从12.94 kJ/m2提高到42.63 kJ/m2,剪切强度从2.06MPa提高到7.12MPa;由动态力学黏弹谱结果可见,体系并非完全相容体系,而是存在着微弱的相分离,玻璃化温度随环氧氨酯含量的变化规律不符合Fox方程,并且随着环氧氨酯质量分数的增加,体系的阻尼性能渐佳,当环氧氨酯含量达到65%时,有效阻尼温域达65℃,最大阻尼因子(tanδ)m ax为0.765,体系阻尼性能优异。

With epoxy resins （ E -44） as matrix, novel self- made epoxyurethanes as toughening agent, self- made curing agent which was the addition product of ethyl acrylate with diethylenetriamine, the epoxyurethane/E -44 blends with different composition weight ratios were cured. The impact strength, shear strength and dynamic mechanical properties of the cured blends materials were determined. The results indicated that the impact strength increased gradually, and the shear strength firstly increased and then decreased with the increasing content of epoxyurethane （ the shear strength achieved the maximum value when the content of the epoxyurethane was 50% ）. The results also showed that the impact strength increased firstly and then decreased and the shear strength reduced gradually with the increasing molecular weight of epoxyurethane. Compared with epoxy （ E - 44） - diethylenetriamine curing system, the toughening effect of blends system were obvious with composition weight ratio of 50： 50. The impact strength was improved from 12.94kJ/m^2 to 42.63kJ/m^2 and shear strength from 2.06MPa to 7.12 MPa. The results of dynamic mechanical spectra indirectly showed that the epoxyurcthane/E -44 blends system was not completely miscible, but partial phase separation existed, the change of glass transition temperature with various contents of the epoxyurethane could not be explained by simple Fox equation. The damping properties were [ （tanδ）max and E＂] improved with the content of epoxyurethane increasing. When the content of epoxyurethane reached 65% （ weight ratio） , the system had excellent damping properties, its efficient damping temperature range reached 65℃ and the maximum damping factor （tanδ） was 0. 765.