| The modified amine of different mole ratios were synthesized by Mannich method,polyether amine TTD, D-230, T-403, phenol, nonylphenol, bisphenol A and formaldehyde asraw materials in this paper. The method also introduced aliphatic diamine （TETA）, alicyclicdiamine （IPDA）, aromatic diamine （MDA） into the Mannich modified polyether amines. Thechemical structures of modified amine were characterized by Fourier transform infrared（FT-IR） spectroscopy. The effects of proportions of reactants on amine value and viscosity ofthe products were studied. The adhesives were made by mixing Mannich modified amines ascuring agent, polyurethane or CTBN as toughening agent and epoxy resin （E-51）. Theadhesive properties, mechanical properties, curing kinetics, thermal performance and dynamicmechanical properties of the curing system which were composed of Mannich modifiedamines and epoxy resin （E-51） were investigated by universal tensile testing machine,differential scanning calorimetry （DSC） and dynamic mechanical analyzer （DMA）.Curing kinetics of the curing system of modified amines and epoxy resin wereresearched by the non-isothermal DSC methods. The curing exothermic peak gradually gotsteeper and shifted to a higher temperature with the increasing of heating velocity. Accordingto the T-β extrapolation, the characteristic temperatures of each curing systems weredetermined which would provide an important basis for the practical curing process. Theapparent activation energy, reaction order, rate constants and kinetic equation of the curingreaction were calculated by Kissinger, Crane and Arrhenius methods.It was evident that the effect of mass fraction of water in the Mannich modified amine onsheer strength. The modified amines whose synthesized mole ratio are3/3/1can significantlyenhance the comprehensive properties, especially sheer strength at high temperature, but thepeel strength come down.The sheer strength on25oC and80oC with different quantity of Mannich modifiedamines for the epoxy resin were tested, and the optimal ratio of Mannich modified amine andepoxy resin was investigated through experiment. It was evident that the effect of thetoughening agent including PU and CTBN on the sheer strength and peel strength of themixture of Mannich modified amine and epoxy resin. For example, the peel strength ofadhesive was13.20kN·m-1 by mixing Mannich modified TTD as curing agent, CTBN as toughening agent and epoxy resin （E-51）. The sheer strength of modified amine at hightemperature increased dramatically. For example, the sheer strength of adhesive was9.75MPa on100oC by mixing Mannich modified D-230as curing agent, PU as toughening agentand epoxy resin （E-51）. The amines which modified by Mannich reaction using IPDA andpolyether amines had a better sheer strength at high temperature. For example, the sheerstrength of adhesive was13.48MPa on120oC by mixing Mannich modified the mixture ofD-230and IPDA as curing agent and epoxy resin （E-51）. The modified amine curing agentshave higher curing rates of cured epoxy resin than ordinary polyether amine at roomtemperature. The modified amine curing agents of cured epoxy resin at room temperature stillhave better sheer strength than polyether amine at high temperature, but the peel strength ofmodified amines come down.According to the tensile property, bending property and impact property of casting resinwhich were composed of Mannich modified amines and epoxy resin （E-51）, it was evidentthat the effect of modified amines on mechanical performance of epoxy resin （E-51）. It wasproved that the glass-transition temperature （Tg） and crosslink density of the curing systemwhich were composed of Mannich modified amines and epoxy resin （E-51） increased. |
