聚天冬氨酸酯型聚脲增韧结构型环氧树脂及其机理

Polyaspartic Acid Ester Polyurea Toughened Structural Epoxy Resin and Its Mechanism

采用聚天冬氨酸酯(PAEs)与异氟尔酮二异氰酸酯(IPDI)反应制备了氨基封端的聚天冬氨酸酯型聚脲(PUA),将其与三乙烯四胺(TETA)共混并对环氧树脂(EP)进行增韧改性。通过红外光谱仪对合成的PUA结构进行了分析,并利用万能电子试验机、悬臂梁冲击试验仪、差示扫描量热仪(DSC)、扫描电子显微镜(SEM)等对PUA增韧改性EP的力学性能、热性能和断面微观形貌进行了表征和分析。结果表明,成功合成了PUA,且当PUA添加量为55份时,材料的拉伸强度为25.8 MPa,同时,其断裂伸长率为22.6%,剪切强度为17.1 MPa,冲击强度为29.1 kJ/m^2,较纯EP分别提高了约4倍、2.6倍、3.3倍。当PUA添加量为60份时,PUA/EP呈现出明显的相分离"海-岛"结构。

Amino-terminated polyaspartic polyurea(PUA)was prepared by the reaction of polyaspartic acid esters(PAEs)and isophorone diisocyanate(IPDI)first.Then PUA was blended with triethylenetetramine(TETA)in order to toughen the epoxy resin(EP).The structure of the synthesized PUA was analyzed by infrared spectroscopy,and the mechanical properties,thermal properties and section microstructure of the PUA toughening modified EP composite were characterized and analyzed by universal electronic testing machine,cantilever impact tester,differential scanning calorimeter(DSC)and scanning electron microscope(SEM).It could be found from the results that PUA was successfully synthesized by the proposed method.When the addition amount of PUA was 55 parts per hundred,the tensile strength of the material was 25.8 MPa.Meanwhile,the elongation at break was 22.6%,the shear strength of PUA toughened EP composites was 17.1 MPa,the impact strength of PUA toughened EP composites was 29.1 kJ/m^2,which were about 4 times,2.6 times and 3.3 times higher than that of pure EP,respectively.When the addition amount of PUA was 60 parts per hundred,the microstructure of PUA/EP composites presented obvious separated phase“sea-island”structure.