Research On Preparation And Properties Of Epoxy Resin Modified With N-(4-hydroxyphenyl)Imide

Epoxy resin,as the most common matrix of fiber reinforced composites,has many excellent properties.With the continuous development of industrial technology,the application of epoxy resin has been deepend in many fields.And more requirement has been put on heat resistance of epoxy resin especially in the territory of high-tech field such as aerospace.Therefore,the modification of heat-resistance still has important research significance.In this paper,the three epoxy-imide resins based on diglycidyl ether of bisphenol-A and N-?4-hydroxyphenyl?maleimide?HPMI?,N-?4-hydroxyphenyl?nadic imide?HPNI?,N-?4-hydroxyphenyl?tetrahydrophthalic anhydrideimide?HPTI?were synthesized,respectively.The structure characterization of the three epoxy-imide resins were measured by FT-IR spectra.4,4'-diaminodiphneylmethane?DDM?was used as curing agent for three epoxy-imide resins.The curing behaviors of the system of HPMIEP/DDM,HPNIEP/DDM and HPTIEP/DDM were studied by the DSC.The results show the cured temperature of HPMIEP/DDM,HPNIEP/DDM and HPTIEP/DDM are 100??2h?,120??2h?,150??2h?,100??2h?,130??2h?,170??2h?and 110??2h?,140??2h?,170??2h?,respectively.At the same time,the dynamic parameters of the three systems were obtained by the results of the DSC test.The activation energy is 52.10KJ/mol,the frequent factor is 2.99×10⁶,and the reaction order is 0.9594 in the HPMIEP/DDM system.The activation energy is 71.55KJ/mol,the frequent factor is 2.98×10⁸,and the reaction order is 0.9308 in the HPNIEP/DDM system.And in the HPTIEP/DDM system,the activation energy is 93.84KJ/mol,the frequent factor is 5.78×10¹⁰,and the reaction order is 0.9317.The thermal properties of the three cured epoxy-imide resins were evaluated with Dynamic Mechanical Analyses?DMA?and Thermogravimetric Analysis?TGA?.The results show that the maximum T_g(T_gmax)of HPMIEP-3/DDM in HPMIEP/DDM system is 205?,T_gmax of HPNIEP-2/DDM in HPNIEP/DDM is 179?,and T_gmax of HPTIEP-2/DDM in HPTIEP/DDM is 186?.The carbon residue of the three modified resin castings increase with the increasing of the content of monomer.The maximum HPMIEP-4/DDM is 19.91%,the maximum HPNIEP-4/DDM is 19.09%,and the HPTIEP-4/DDM maximum is 19.41%.And the maximum of the flexural strength and modulus of HPMIEP-3/DDM in HPMIEP/DDM are 86.1MPa and 2.9GPa,respectively.The maximum of the flexural strength and modulus of HPNIEP-2/DDM in HPNIEP/DDM are 93.9MPa and 3.0GPa,respectively.The flexural strength and modulus of HPTIEP-2/DDM in HPTIEP/DDM are 95.7MPa and 3.0GPa,respectively.