The Preparation And Characterization Of Composite Modified Silicone Resin With Low Surface Energy

The low surface energy resin is a kind of resin whose coating has low surface tension through a certain molecular configuration. The present common resins are modified fluorocarbon resin and silicone resin which are widely used in marine industry, electric products, building engineering and so on.The traditional method of silicone modification is generally based on physical mixing. Due to the good chemical stability of the group on polymer chain, there is no chemical reaction between the silicone and its modifier, so the microscopical compatibility of composite resin is poor, which reflects the lack of effect modification on the macroscopy. In this study, the silicone was modified by chemical methods which increased the compatibility between the two resins.Kinds of silicone/EP and silicone/PU resins were composite modified by using the epoxy and polyurethane resin as modifiers and silicone resin, silicone rubber and silicone oil as the matrix materials, respectively. The effects of curing agent with different types, percent and formula types on curing performance were investigated, and the optimum formulation was determined. Through infrared spectroscopy (IR), scanning electron microscopy (SEM), dynamic mechanical analyzer (DMA), atomic force microscope (AFM) and contact angle tester were used to investigate the synthesis of copolymers, and the morphologies on the surface and fracture of the coatings without or with different modifiers, glass transition, and the relationship between contact angle and hydrophobicity or surface energy were studied.The result showed a good micro-compatibility between the silicone resin and modifier. In certain scope, the greater the surface roughness of composite copolymer was, the smaller the surface energy would be, the better hydrophobicity would be, and the greater the contact angle would be; the micro-compatibility was worse between the silicone rubber(or silicone oil) and PU, the fracture surface of coatings became so rough that the contact angle was smaller.The study also found different composite resin had the specific solidification system, and the resin could fully solidify at room temperature and the cure rate was faster. This article also discussed various methods to calculate surface energy by using contact angle, and identified the most suitable method for calculating surface energy.