Preparation And Properties Research Of Novel Bio-based Epoxy Resins

Epoxy resin,as one of the most high performance thermosetting materials,has been widely used in electronics industry,construction,medical product,auto industry and aerospace.Meanwhile it provides the support for the human development all the time.Nowadays,there are two factors that restrict the development of epoxy resin significantly.First,almost all of the epoxy resins are produced from fossil resources.As a non-renewable resource,fossil fuel has limited storage capacity.Secondly,bisphenol A and bisphenol F as two kinds of raw material of conventional epoxy resins possess the estrogenic activity because of the similar structure to estrogens,which have been recognized as the endocrine disruptor.Thus,the development of bio-based epoxy resin as an alternative of traditional epoxy resin has become a crucial strategy for the thermoset application in the future.The purpose of this study is to prepare a series of environmentally friendly bisphenol monomers derived from biotic resource to replace the bisphenol A as the precursor of epoxy resins to satisfy the requirement of human.It will be a significance meaning of sustainable development of society and environment.Firstly,we prepared three kinds of novel biobased bisphenol monomers BEF,BGF and MBHF from biotic resource eugenol,2-methoxy-4-methylphenol and guaiacol respectively.Then these structures of bisphenol monomer was confirmed by~1H-NMR and compared their estrogenic activity with estrogen and commercial bisphenols(BPA and BPF)by amethylthiazolyldiphenyl-tet-razolium bromide(MTT)assay using MCF-7(human breast adenocarcinoma cell line)as an estrogen receptor(ER).The result showed the biobased bisphenol BEF?BGF and MBHF exhibited extremely lower cell proliferation rate than above positive controls.Therefore,they can be considered as a genuinely safer alternative to BPA and BPF.Secondly,we prepared three kinds of biobased epoxy resin from BEF,BGF and MBHF according to the reaction of bisphenol and epichlorohydrin.Then their structures were confirmed by ~1H-NMR.After curing reaction,we studied the properties of three kinds of biobased epoxy resin.The results exhibited that,biobased epoxy material MBHF-EP possessed the highest storage modulus(2387 MPa),glass transition temperature(151 ~oC),coefficient thermal expansion(68.07 ppm)and contact angle(92.09°)among all the biobased epoxy resin.Next,we utilized diatomite as the reinforcement material,BEF-EP as the epoxy matrix and prepared a series of epoxy/diatomite composite materials.According to the results of curing kinetics,DMA,TGA and contact angle research,it showed the properties of epoxy composite materials were improved with the diatomite content increasing.Finally,on the basis of chemical structure designing,we prepared a novel bio-based curing agent from 2-methoxy-4-formylphenol(vanillin).Compared with traditional curing agent benzimidazole(BZMI),we prepared a series of epoxy materials with different curing agents,including VBZMI.The result displayed,the VBZMI cured epoxy material exhibited higher performance than BZMI cured epoxy material.For instance,BPF-EP/VBZMI showed the highest storage modulus,thermal stability and glass transition temperature among all the epoxy materials.