| Epoxy resin, as a widely used polymer material, has been improved and enhanced continuously with the development of technology, which in order to meet the urgent need of technological development. Trifunctional epoxy resin—tri(4-hydroxyphenyl)methane epoxy resin, after being cured with curing agent, exhibits high crosslinking density, excellent heat resistant ability as well as supreme mechanical and optical properties. Synthesis process of the tri(4-hydroxyphenyl) methane epoxy resin were then studied in this dissertation. And the thermal property of the epoxy resin was also tested. A high-resistance epoxy resin with low viscosity was synthesized after copolymerizing with bisphenol A, laying good foundation for the application of this kind of epoxy resin.The main results and conclusions of this thesis are listed as follows:Firstly, the tri(4-hydroxyphenyl)methane was synthesized by using phenol and p-hydroxy benzaldehyde as the feed stock, p-toluenesulfonic acid and aluminium chloride as relative catalyst. Four factors such as reaction temperature, usage of catalyst, material ratio and reaction time was studied in detail in experiment. Under the optimized processing parameter, the yield of product can reach more than90%, and the purity of the product is up to as high as99%by the test of liquid chromatography.Secondly, the tri(4-hydroxyphenyl)methane epoxy resin was synthesized by using tri(4-hydroxyphenyl)methane and epichlorohydrin in a two-step technique. Then four factors affecting the yield and the epoxy value of production were studied, including the addition manner of the alkali, the usage of catalyst, closed loop temperature, the speed of adding alkali. The results showed that under the optimal condition, the epoxy value of the epoxy resin is0.62, the yield is up to85%, the viscosity under25℃is70000mPa-s. And the optimized synthesis process of TMP-BPA copolymerized epoxy resin was synthesized by orthogonal method and single factor test. The epoxy value of the as-prepared epoxy resin is0.59, the viscosity under25℃is reduced to9000mPa·S. The structures of tri(4-hydroxyphenyl)methane, tri(4-hydroxyphenyl)methane epoxy resin and its copolymerization epoxy resin were confirmed by analysis of FTIR and NMR spectrum.Thirdly, utilizing DDM, MHHPA and PA as the curing agent for epoxy resin, curing behaviors of epoxy resin systems and curing conditions were investigated by means of non-isothermal DSC method. The apparent activation energy and the orders of reduction reaction were obtained according to Flynn-Wall-Ozawa and Kissinger methods. The activation energy calculated by Kissinger method is slightly higher than Flynn-Wall-Ozawa method.Fourthly, the glass transition temperature (Tg) and the thennolysis temperature of cured epoxy resin were tested by DSC and TGA, and the results were compared with bisphenol-A epoxy resin. The results showed that the Tg of TMP/DDM and TMP-BPA/DDM is up to180℃, which is30℃higher than BPA/DDM. And the5%thermal decomposition temperature is360℃, which is50℃higher than bisphenol-A epoxy resin.All above studies and experiments show that tri(4-hydroxyphenyl)methane epoxy resin has excellent comprehensive performance. The epoxy value was improved the epoxy value was enhanced and the viscosity was reduced by means of the process optimization and copolymerization which improving the performance of high-resistance epoxy resin. |
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