不同环氧当量超支化环氧树脂/双酚A型环氧树脂固化体系的相结构

Phase Structure of Hyperbranched Epoxy Resin/Bisphenol A Epoxy Resin Curing System with Different Epoxy Equivalents

采用光学显微镜研究了不同环氧当量的端羟基超支化环氧树脂(EHBP-n,n=3,6,9,12)/双酚A型环氧树脂(EHBP-n/DGEBA)固化体系的相结构,探讨了EHBP-n/DGEBA固化产物的微观形貌和力学性能的关系。结果表明:随着端羟基超支化环氧树脂质量分数的增加和环氧当量的减小,固化产物的相容性提高。固化微观结构中粒子的尺寸越大,力学性能越好。原位在线观察了9%EHBP-12/DGEBA(EHBP-12的质量分数:9%)的固化过程,提出了均相结构形成的机理。用差示扫描量热法研究了EHBP-12/DGEBA的固化动力学,用扫描电镜背散射电子成像对固化产物的元素分布进行分析,进一步说明EHBP-n与DGEBA具有良好的相容性。

The phase structures of hyperbranched epoxy resin/bisphenol A epoxy resin(EHBP-n/DGEBA)curing systems were studied by optical microscope.The relationship between the morphologies and mechanical properties of EHBP-n/DGEBA cured products was discussed.The results showed that the compatibility of the cured products was improved with the increase of EHBP-n mass fraction and the decrease of epoxy equivalent.The larger the particle size in the microstructure of the cured products was,the better the mechanical properties were.The curing process of 9%EHBP-12/DGEBA(the mass fraction of EHBP-12:9%)was observed and the formation mechanism of homogeneous structure was proposed.The in-situ strengthening and toughening mechanism of hyperbranched polymer was confirmed.The curing kinetics of EHBP-n/DGEBA was studied by Differential Scanning Calorimetry(DSC),and the element distribution of the cured product was analyzed by Mapping.It further showed that EHBP-n had good compatibility with DGEBA,and it was a non-phase separation system after curing.