International. Researchers in China have prepared two new epoxy curing agents containing bio-based phosphorus derived from myrcene and castor oil and investigated the comprehensive properties of their combined cured products.
The molecular structures of both epoxy curing agents (MMDOPO and MAPDGR) were characterized by FTIR, 1H and 1HNMR. They were then mixed at different proportions by weight to form new curing agents for epoxy resin (E-51).
The results show that the tensile and bending strength of cured epoxy materials increase first and then decrease with increasing MMDOPO content. Dynamic mechanical analysis (DMA) shows that the glass transition temperature (Tg) increases significantly with the increase in MMDOPO.
The thermal stability of the material and the flame-retardant properties were also investigated. The initial decomposition temperature (Ti) and the limiting oxygen index (LOI) are both elevated while the residue decreases with the increase in MMDOPO. When the weight ratio of MMDOPO / MAPDGR is 25:75, the mechanical properties are relatively balanced with a high elongation at break of 160.8% and a moderate tensile strength of 9.95 MPa, and the bending test indicates that the sample exhibits a flexible failure behavior with a performance point.
Source: http://www.sciencedirect.com
