| Epoxy resin and Polyimide (PI) are two types of resins. It's well known that epoxy adhesive is prominent in adhesive strength, which can be cured at low temperature and blended with other resin, but poorness in heat-resistant property. PI has many advantages, such as good comprehensive properties, various synthesis routes, simple and plentiful monomer. PI also has some defects, for instance, solvent in the condensation PI adhesive is dificult to remove, it is hard to process PI adhesive at high tempreture. Therefore, epoxy cementing compound had proved to have good mechanical properties and cohesional strength because they can combine the advantages of epoxy resin and polyimide resin by the mixing of two resins for their complementary properties.In this paper, epoxy resin was modified with polyamide acid(PAA), adding some carboxyl end group nitrile rubber(CTBN), diaminodiphenylsulfone(DDS) as curing agent. Pre-reaction was completed at certain temperature first, and then it was cured under some process conditions. The epoxy resin with good heat resistance was obtained by adjusting the ratio and process conditions. The effects of the amount of PAA, DDS, CTBN, curing condition, reaction time on the heat resistance and mechanical properties of epoxy resin were studied in particular. A better formula was chosen to determine the appropriate conditions for curing. The heat resistance and mechanical properties of modified epoxy resin were measured by thermal gravimetric (TG) analysis instrument and differential scanning calorimeter (DSC) instrument in different proportions, pre-reaction time and different curing conditions. Moreover, the conformation of each resin was characterized by Fourier Transform Infrared Spectrum (FTIR). Then the surface and the fracture surface morphology of adhesive membrane were analyzed by Scanning Electron Microscope (SEM). Through mechanical performance test, thermodynamics experiment and lastingness study, the optimal mass proportion got is EP: PAA: DDS: CTBN = 1:0.75:0.08:0.08, better conditions of the process of the resin, curing temperatures are 120℃and 150℃for 1h respectively, then 170℃, 200℃and 250℃for 2h respectively, pre-reaction time is 3h. After adding PI, the thermal deformation temperature of adhesive can reach 411℃, raised 80℃than the resin unmodified. At a certain range of pressure and temperature, the shearing strength and peel strength are high up to 27.10MPa and 22.50KN/m, respectively. After aging, the strength hasn't obvious change, and the moist heat resistance also has a good performance. The analysis of TG and SEM indicated that the resin modified have a good compatibility.
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