| Epoxy resin was a kind of widely used thermosetting resin.Because of excellent adhesion,corrosion resistance and high strength after curing,epoxy resin was widely used in non-metallic and metal materials bonding,anti-corrosion coatings,insulation materials and Composite materials and so on.In many industrial areas,epoxy resin occupied an increasingly important position,becoming indispensable basic material for all walks of life.However,the epoxy resin matrix had disadvantages such as poor heat resistance and insufficient toughness.If these shortcomings were not overcome,it was difficult for epoxy resins to be used in more severe conditions.In order to improve the heat resistance,heat-resistant components had been added into epoxy resin matrix.Besides,heat-resistant groups have been used to modify the resin structure or the curing agent structure.This article was intended to synthesize new structures of epoxy resin,curing with ordinary curing agent to obtain good heat resistance of epoxy resin products.The Cyano-based bisphenol A-type compound BPCN and the containing cardo ring and cyano bisphenol compound PPCN were synthesized by nucleophilic substitution,followed by synthesising the corresponding epoxy resin BPC E and PPCE by addition polymerization.And the optimal synthetic conditions of PPCE were studied.The two kinds of new epoxy resins were cured with methylnadic anhydride(MNA),respectively.The curing behavior and heat resistance of BPC E/MNA,PPCE/MN A and E-51/MNA were analyzed by DSC,DMA and TGA.The introduction of cyano and cardo rings was discussed on the heat resistance of epoxy resin.The structure of the product was confirmed by IR and NMR spectroscopy.The curing processes of BPCE/MNA and PPCE/MNA resin system were studyed by DSC.The activation of the two systems was one step and the two reaction activation energy were 57.78 kJ/mol and 58.16 kJ/mol.The glass transition temperatures of the BPCE/MNA and PPCE/MNA resin systems were 156 oC and 179 oC,respectively,higher than the E-51/MNA system obtained under the same curing conditions.The initial decomposition temperatures of BPC E/MN A and PPCE/MNA resin systems were 328 oC and 327 oC,respectively,and the residual carbon ratios of the cured products were 24.0% and 40.3%.The thermal decomposition of BPCE / MNA was carried out in three steps.The thermal decomposition of PPCE / MNA was carried out in two steps.Co mpared with the commercial E-51/MNA system,the two kinds of new epoxy resin curing with acid anhydride have better thermal properties. |
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