Study On Green Method Synthesis Of Epoxidized Eucommia Gum And Its Composite Epoxy Anticorrosion Coating

Eucommia gum is a kind of unique biomass polymer material in China.Its structure is similar to natural rubber,and it is trans-1,4-polyisoprene.It has good resistance to chloride ions,acid and alkali,and strong insulation.Since 2018,the country has implemented an export restriction strategy for eucommia gum,but there are few domestic studies on the development and utilization of eucommia gum.In order to solve the compatibility of eucommia gum and epoxy resin,and expand its application in the field of anti-corrosion,this paper developed a green interface synthesis modification method,introducing epoxy groups into the eucommia molecular chain to solve its compatibility with epoxy resin,and at the same time solve the problem of environmental pollution caused by the traditional method of preparing epoxidized eucommia gum using a large number of toxic solvents;then use it as a nanofiller for modified epoxy anticorrosive coating,to study the performance change of the modified coating,and analyze its mechanism of action,including the following two parts:(1)Study on the synthesis of epoxidized eucommia gum by interfacial method.Utilize the terminal hydrophilic group of eucommia molecular chain and the loose porosity of eucommia gum solid,use deionized water instead of organic solvent as dispersant,and generate peroxyacetic acid in situ through glacial acetic acid and hydrogen peroxide.The epoxidation reaction takes place at the phase interface,so that the unsaturated double bond on the molecular chain of eucommia gum is epoxidized,and the product can be obtained by directly filtering after the reaction.By adjusting the reaction time and the molar ratio(η)of hydrogen peroxide,glacial acetic acid and eucommia gum,infrared spectroscopy and nuclear magnetic resonance technology were used to study the degree of epoxidation under different conditions.The study found that with the extension of time,the amount of acetic acid increased,and the side reactions of epoxy ring opening increased.When the reaction time is 6 hours andηis 0.6,the epoxidation degree of eucommia gum is the highest.The epoxy value of epoxidized eucommia gum measured by chemical titration is 0.120mol/100g resin.(2)Research on epoxidized eucommia gum modified epoxy anti-corrosion coating.The epoxidized eucommia gum prepared above is used as a nano-filler in epoxy coatings to prepare an epoxidized eucommia gum/epoxy resin composite coating.The effects of different amounts of epoxidized eucommia gum on the corrosion resistance of epoxy composite coatings were studied by AC impedance method and neutral salt spray experiment.The results show that epoxy composite coatings doped with 1%EEUG have the best anti-corrosion performance,for example,the low frequency impedance value of the composite coating is still above 10~8Ωcm~2after immersed in 3.5%Na Cl for 30 days.After 300 hours of neutral salt spray test,there is basically no corrosion phenomenon observed on the metal substrate.The mechanism of action was analyzed by thermo-gravimetric-differential calorimetry scanner combination and tensile testing,and it was found that the doped epoxidized eucommia gum can be used as a reactive nano-filler to enhance the crosslink density of the epoxy coating and enhance the permeability resistance of the composite coating to the electrolyte solution.