Preparation and properties of a new bio-based epoxy resin/diatomite composite

Abstract In this study, a series of sustainable epoxy resin/diatomite composites were prepared by using the synthetic bio-based 2,2′-diglycidyl ether-3,3′-dimethoxy-5,5′-diallyl diphenylmethane (BEF-EP) as the matrix resin and silanized natural diatomite as the reinforcing filler. After cured with methylnadic anhydride and benzimidazole at different proportions of diatomite fillers, the morphology and properties of BEF-EP/diatomite composites were investigated and compared in detail. Due to the good compatibility between the epoxy resin matrix and silanized diatomite, the diatomite is uniformly dispersed in the matrix without large-scale agglomeration. With the addition content of diatomite increasing, the storage modulus of BEF-EP/diatomite composites increased from 2281 to 2983 MPa at 25 °C. The initial degradation temperature (Td5%) showed an increasing first and then decreasing tendency as the content of diatomite increased, while the Td50% and Tdmax values of BEF-EP/diatomite composites also increase with the content of diatomite increasing. Especially, BEF-EP/diatomite 20% showed excellent thermal stability with Td5% of 287 °C, Td50% of 485 °C, and Tdmax of 412 °C. The results indicated that the mechanical and thermal stability of epoxy resin composites could be significantly improved after the incorporation of diatomite. Furthermore, the bio-based BEF-EP/diatomite composite could be used as the renewable and sustainable alternatives to petroleum-based epoxy resin composites.