Preparation Of Thermal Resistance Epoxy Resin And Its Curing Kinetics

With the development of integrated circuit, electronic technology , requirement of thermal resistance of corresponding materials is increasing. Cured epoxy resins have excellent chemical resistance, corrosion resistance, dimensional stability, mechanical and electrical properties, which have been widely applied. However, the commonly used epoxy resins cannot meet the use in high temperature condition. In this paper, a variety of epoxy resin substrates, curing agents and modifiers were chosen to form formula, and optimize the curing process to prepare thermal resistance epoxy resins.The main contents are as follows:Preparation of thermal resistance epoxy resin.Three kinds of epoxy resin substrates,five kinds of curing agents were selected to compose of 15 kinds of epoxy resin systems. The mechanical and thermal properties of different epoxy resin systems were analyzed .Suitable epoxy resin substrate was 4,4' -diaminodiphenylmethane tetraglycidyamine(AG80) or triglycidyl p-aminophenol(AFG90), and the curing agent was methylhexahydrophthalic anhydride(MeHHPA). Modifiers polypropylene glycol diglycidyl ether(PPGDGE),benzyl glycidyl ether(692),C12?C14 alkyl glycidyl ether(AGE) and n-butyl glycidyl ether(501) were added in the systems, respectively.Comparing their effects on the mechanical properties of AG80/MeHHPA and AFG90/MeHHPA systems, PPGDGE and 501 improved the mechanical properties of resin systems obviously. The relationship between the addition of PPGDGE, 501 and the mechanical properties, thermal resistance of epoxy resin systems were studied.When the mass ratio of 501, AG80, MeHHPA was 20:100:155, an epoxy resin system 20wt%501/AG80/MeHHPA with excellent thermal resisitance and mechanical properties was obtained. The initial decomposition temperature of prepared thermal resistance epoxy resin reached 310?, the bending strength and tensile strength were 69,2MPa and 24.5MPa, respectively.The non-isothermal curing kinetics. The effects of the addition of 501 on the curing behavior of AG80/MeHHPA were studied by differential scanning calorimetry(DSC).The initial curing process, apparent activation energy, relationship between conversion rate and temperature of each system were obtained. With the increase of 501, the isothermal curing temperature of systems were gradually reduced, the apparent activation energy calculated by Kissinger equation and Ozawa equation also decreased, while the reaction order calculated by Crane equation fluctuated around 0.93, this indicated that the reaction process accompanied by the occurrence of side effects. The n-order reaction kinetics model and the autocatalytic kinetics model were used to study the curing kinetics of the systems. The n-order reaction kinetics model could not be used to describe the curing process of the systems, while the autocatalytic kinetics model could be used to describe the curing process of the systems. The Friedman method, FWO method and KAS method were used to study the curing kinetics of the systems. The addition of 501 had a certain effect on the reaction mechanism of the systems.20wt%501/AG80/MeHHPA was taken as resin dipping colloidal solution, and fibers were immersed in the colloidal solution and wound into composite bearings.The bearings met the requirement.