Studies On Modification Of Epoxy Resins

This paper introduced phenolic resin and acrylic resin to modify epoxy resin, and studied the synthesis and properties by adding nano-silica.The nano-silica modified phenolic resin pre-polymer was prepared by using bisphenol A and formaldehyde as basic materials and adding nano-silica.The nano-silica modified phenolic resin was obtained by copolymerization of the pre-polymer and epoxy resins. The product was investigated and characterized by IR, particle size distribution, scanning electron microscope and property test of the coating films. The results showed that the nano-silica dispersed in the copolymer uniformly and it indicated that the hydroxy groups of nano-silica took part in the copolymerization of phenolic resins. The addition of nano-silica had little effect on the structure of phenolic epoxy resins. The water boiling resistance, yellow temperature, hardness, water absortion rate and saline corrosion resistance of the coating film could be improved effectively by adding the nano-silica compared with the unmodifified phenolic epoxy resins.The nano-silica modified acrylate resin pre-polymer was prepared by using acrylic acid as basic materials and adding nano-silica. The nano-silica modified acrylic resin was obtained by copolymerization of the pre-polymer and epoxy resins. The product was investigated and characterized by SEM, DSC, TG and property tests of the coating films. The results showed that the nano-silica dispersed in the copolymer uniformly and it indicated that the hydroxy groups of nano-silica took part in the copolymerization of epoxy acrylate resins. The addition of nano-silica had improved the weatheability of the copolymer. The water boiling resistance, yellowing temperature, hardness, water absorption rate and saline corrosion resistance of the coating film had be heightened effectively by adding the nano-silica compared with the unmodified epoxy acrylate resins.The acrylate resin pre-polymer was prepared by using acrylic acid as basic materials. The acrylic modified epoxy resin was obtained by the copolymerization of the pre-polymer and epoxy resins, and crosslinked by aminopropyltriethoxysilane, 2,2'-(1,3-phenylene)bis(2-oxazoline), IPDI-trimer and IPDI-hybridtrimer. Compared the water logging and boiling resistance, water absorption rate, yellowing temperature, hardness, adhesive force and saline corrosion resistance of the coating film and selected the suitable curing agent and volume of addiction to solidify the acrylic modified epoxy resin.