Preparation And Study On Properties Of Epoxy Resin Modified By Poly(Ether Sulfone)/Nano-Silica

Epoxy resin (EP) adhesive had great bond behavior and was widely applied in Aerospace, military, electronic, construction and many other fields. However, as a structural tackiness agent, the application of the unmodified epoxy resin was limited because of its high brittleness. PES is thermoplastic with good toughness as well as high elastic modulus, chemical resistance, and thermal resistance, by which EP can be modified combining the advantages of the high toughness and rigidity. Nano-silica(SiO₂) is inorganic rigid particle who has a high module itself and quantum size effect, small size effect, surface effect, macroscopic quantum tunneling, so, it shows a lot of peculiar properties. For modifying EP resins, the modified resin has increasing mechanical properties and heat-resistance with low content. In this paper, a macromolecular PES and nano-silica were both used as modifier and then prepared adhesive which had better performances than the resin modified with a single mothed.PES was used to modified EP resin and liquid anhydride methyl tetrahydrophthalic anhydride (MeTHPA)was used as curing agent meanwhile take the part in resolving PES, then prepared PES-EP precursor and take the micro-morphology analysis and structure characterization. The reactant ratio was investigated by the analysis of shearing strength, TG, SEM and dielectric properties of the cured resins. The results showed that the resin containing 15wt% PES showed the best properties, the shearing strength increased 72% more than that of the pure epoxy resin, and the Onset temperature of the composite increased about 10℃, at the same time, the dielectric constant and the dielectric loss both have a low value.The nano-silica partical was easy to agglomerate, so coupling technique was taken to modify the surface properties of silica. Different contents of nano-silica were added into PES-EP precursor with 15wt% content of PES, then prepared SiO₂/PES-EP adhesive and took the measure of SEM, shearing strength, impacting strength, TG and dielectric properties of the cured resin. The result showed that, adding nano-silica increased the impact strength but slightly decreased the heat-resistance. In the resin with 2wt% nano-silica, the morphology showed a best dispersion and the increase of the mechanical properties was significant.