Study And Preparation Of Water-Borne Epoxy Resin System

There are many excellent properties of epoxy resin, such as good mechanical properties, excellent corrosion resistance and adhesion, and very good process performance in the experiment. Due to its high viscosity, organic solvents are necessary in the usage of most epoxy resin. While the use of organic solvent is not only caused serious environment pollution, but also has a great threat to the health of the human. Therefore, our work was focused on the research of environmentally friendly waterborne epoxy resin which can be dispersed in water. Hydrophilic groups or segments were introduced into the epoxy resin structure, which lead to the dispersion of epoxy resin in water stably. In this paper, chemical modification methods were used to modify epoxy resin, and enabled the stable dispersion in water of the waterborne epoxy resin. Through phase inversion method to prepare waterborne epoxy resin emulsion from the modified eoxy resin under certain condition, and its properties were charcaterized. The main work is as follows:1、Under certain conditions, through the reaction of epoxy group and hydroxyl group of polyethylene glycol, polymer with functional groups were obtained. Furthermore, the resulting polymer had a good hydrophilicity for the hydrophilic polyether segment introduced in the process of experiment. Epoxy value determination was used to characterize the changes of experiment process, and the modified epoxy structure was identified by FTIR spectrum and further characterized by gel permeation chromatography. In this paper, the influence of different parameters on the preparation of polyethylene glycol modified epoxy resin was studied, such as reaction time, temperature, ratio of reactants, catalyst type and dosage. The optimum conditionsare:reaction temperature is90℃, time is6h, and use E-20of epoxy resin, and the ratio of epoxy resin and polyethylene glycol is1:1, catalyst dosage of boron trifluoride ethyl ether is1%, and the amount of propylene glycol methyl ether used as solvent is the same as the total mass of reactants.2、Under certain conditions, methyl acrylate, styrene, butyl acrylate are grafted to the etherification epoxy resin to prepare self-emulsifier. In this process, KOH-anhydrous ethanol method was used to monitor the changes of the acid value and reaction degree. The structure of the final product was characterized by fourier infrared spectrum, and particle size and distribution of the waterborne epoxy resin emulsion was also characterized. In addition, the stability of the emulsion and the morphology of latex particles were analyzed. The optimumrecipe was: the reaction time and temperature was6h and90℃respectively, and the amount of benzoyl peroxide was1%, the ratio of butyl acrylate:styrene: methacrylic acid was1:1:1.5, and the amount of all monomers was28%of reactants. The solvent was obtained by n-butyl alcohol:propylene glycol methyl ether was3:2. The particle size of the waterborne epoxy resin emulsion was86.1nm and had a narrow distribution, and this emulsion can stable preserved in room temperature for6month with no delamination, and after centrifugation for60min under the speed of3000r/min, no delamination was observed in the emulsion.3、The waterborne epoxy resin emulsion was prepared from the former modified epoxy resin by phase inversion technology, and it had great stability and small particle size. At the same time, the modified epoxy resin was used as emulsifier to emulsify epoxy resin, the result indicated the excellent emulsion performance and the waterborne epoxy resin was successfully obtained with emulsion particle size less than100nm.