Preparation And Performance Study Of SiO₂/Epoxy Composite Materials

SiO₂/Epoxy composite materials are important hybrid materialswith excellent properties， which combine advantages of inorganicmaterials and organic materials， such as high rigidity, thermostability,toughness, easy-treating and so on. Therefore epoxy resin is applied inconstruction, mechanical, aerospace, coating, electric and electricalapplication. These composite materials expand the application of epoxyresin in harsh environment conditions and special domains, such as lowtemperature and aerospace. The research of epoxy resin compositemodified by nano-particles draws much attention of domestic andforeign researchers.（1） Monodisperse SiO₂microspheres were synthesized byimproving St ber method using concentrated ammonia solution as acatalyst, with hydrolysis and condensation of TEOS in ethanol solution.The monodisperse SiO₂microspheres were characterized by X-raydiffraction, infrared spectroscopy and Field emission scanning electronmicroscopy. The result indicated that the silica microspheres dispersedwell and were surface uniformity.（2） SiO₂microspheres were modified by MPS and NaCl electrolytesolution. The influence on SiO₂microspheres particle size and the Zetapotential was discussed though changing the MPS concentration andNaCl electrolyte solution concentration. The results showed that: theparticle size and Zeta potential value of SiO₂microspheres improvedafter the modification, also the particles were stability and not easy tounite together; Silica@Ag particles were prepared by silver mirrorreaction, researched by UV/Vis transmission spectra, it happened redshift phenomenon which proved that nano silver particles had generated on surface of Silica. Along with the increase of silver ammonia solutionconcentration, the size of silver particles increased, and the reunionphenomenon occurred.（3） SiO₂/Epoxy composites were prepared by the physical blend.The composites were characterized by FESEM, universal mechanicaltesting machine. The results showed that: the toughness, fractureelongation and tensile strength changed significantly, and the influenceof particle size and amount of SiO₂, the MPS-SiO₂composite wasdiscussed. Tensile property of epoxy resin composites modified byMPS-SiO₂was better than that of SiO₂.（4） Polymer blends were prepared by radical polymerization ofMPS-SiO₂, methyl methacrylate, styrene and epoxy resin, under theconditions of benzoyl peroxide as initiator, taking polyamide resinBS650as curing agent, a new type of composite was prepared.Composites were characterized by tensile test. a L4（2³） orthogonal testwas designed. The results showed that: the tensile properties of suchpolymer blends increased significantly, the primary and secondaryinfluencing factors were determined by the orthogonal test.