| Epoxy resin has excellent adhesion properties, mechanical properties, chemical stability, dielectric properties, and low volume shrinkage, good processing performance, low cost, etc. So it is widely used in adhesives, coatings, machinery, construction, electrical insulation materials and other fields. Because the molecular structure of epoxy resin contains reactive epoxy groups, the epoxy groups can react with many other active groups, thereby performing crosslinking, but because of higher crosslink density after curing, resulting in brittle products, low toughness and poor heat resistance, it can not meet the requirements of high-performance materials in engineering technology. For this reason, it is necessary to modify epoxy resin to have a better overall performance.In this experiment, use E51 epoxy resin and boron phenolic resin as raw materials to prepare BPF/EP samples whose weight ratio are 1, 2, 3 and 4, and prepare casting body. Study the gel properties and viscosity characteristics of modified resin matrix and calculate the activation energy and flow activation energy by doing linear fit. Its epoxy value, oxygen index value and the impact strength was tested, and investigate the effects of BPF content on each performance.The gel properties of BPF/EP resin system was determinated by using the flat knife method and the apparent activation energy was calculated for each modified epoxy resin, the results show that with the increase of BPF resin content, activation energy of BPF/EP resins exhibit different degree of drop, activation energies were 81.6kJ/mol, 75.2 kJ/mol, 70.3 kJ/mol and 67.7kJ/mol from recipe1 to recipe 4; The curve of dynamic viscosity and temperature of the resin system is distributed by U-shaped, the viscosity of low viscosity platform of the different components increases with the increasing of BPF content, corresponding temperature range of low viscosity platform is also reduced and there is tendency to move to higher temperatures. With the increasing amount of BPF, flow activation energy of modified resin increases.The curing kinetics of modified epoxy were studied by using DSC. Use Starink equation, Kissinger equation and Crane equation to calculate the apparent activation energy Ea, pre-exponential factor A0 and the reaction order n and derive curing kinetics equations for each recipe. It was found that with increasing of BPF resin content, the apparent activation energy decreased and get their curing process parameters according to T~β curve extrapolation.Thermal decomposition kinetics of modified epoxy resin were studied by using TGA. Use boswell equation, Starink equation, Kissinger equation and Crane equation to calculate the apparent activation energy Ea, pre-exponential factor A0 and the reaction order n and derive the decomposition kinetics equation of each formulation, providing a theoretical basis study for decomposition reaction of BPF/EP system at a high temperature.BPF/EP/Glass fiber composites were prepared by lamination molding and test their basic physical properties, such as the relative density and content of the resin matrix, the results show that density of composite sheet is 1700~1900kg/m3 range, the resin content is about 30%. While its impact and bending properties were tested, the test results show that the impact strength of the resin system is the biggest which contains 10% BPF, having best performance. With the increase of BPF resin content, impact strength decreased. The flexural strength was first decreased and an increasing trend with increasing the amount of resin, the bending strength has maximum when BPF content is 40%. |
