Ultratough Epoxy Resin Based on an Ionic Complex from Phytic Acid
Gaobo Lou, Xingwei He, Wangbin Zhang, Qingqing Rao, Shenyuan Fu, Lina Liu, Yi Kuang, Jinfeng Dai
Abstract
In this study, phytic acid (PA) and 1,10-diaminodecane (DAD) were neutralized in a single step to develop the biobased ionic complex PA-DAD, which was then utilized as a toughener to increase the toughness of epoxy resin (EP). As a result of the sacrificial ionic bonds between DAD and PA, the fracture toughness of composites containing PA-DAD was substantially enhanced. Compared to neat EP, the tensile and flexural toughness of composited EP increased by 697 and 1028%, respectively, when PA-DAD was added at 6 wt %. Additionally, impact, tensile, and flexural strengths were enhanced by 201, 42, and 45%, respectively. Moreover, the modified EP had favorable flame retardancy due to the high phosphorus concentration of PA-DAD. The EP/6% PA-DAD showed a 27.7, 24.2, and 29.6% decrease in total smoke production, total heat release, and peak heat release rate, respectively, as compared to neat EP. The results of this investigation suggested a simple approach to toughening EP systems, which would expand the use of biobased tougheners.