| With the rapid development of the economy,the problem of environmental pollution has become an important issue that needs to be solved urgently in the 21 st century.Among them,the change of coating resin from oil to water has become one of the best ways to solve the solvent pollution in the coating process.The ultraviolet(UV)curing aqueous modified epoxy acrylic acid(EAG)resin studied in this subject adopts the method of UV curing film formation.The UV curing waterborne epoxy acrylic resin has the following advantages.1.Photocuring at normal temperature;2.Suitable for heat sensitive substrate surface;3.Fast curing speed(< 20 s),short construction time,high production efficiency;4.Low energy consumption and low cost.The waterborne resin synthesized by the subject is a cationic waterborne resin,which has good water solubility,has good physical and chemical properties after photocuring,and has little environmental pollution.In order to improve the defects of traditional waterborne UVcurable resin film formation,the main research contents are as follows:(1)Epoxy acrylic acid monoester(EAM)synthesized from bisphenol A epoxy resin E51(EP-E51)and acrylic acid(AA)as the main chain.Semi-blocked isocyanate synthesized from diisocyanate(TDI),polyethylene glycol(PEG)and hydroxyethyl acrylate(HEA)as grafting segments.We are introduced ether group(-O-)and C=C.Finally,the epoxy group of the main chain undergoes a ring-opening reaction with diethanolamine(DEA),and a cationic aqueous resin is synthesized by adjusting the pH of the acetic acid system.We determined the specific parameters of the aqueous resin synthesis process,and characterized the prepolymer structure,and tested the storage stability of the waterborne resin in water.(2)We have studied the optimal conditions for the synthesis of semi-blocked isocyanates with different molecular weight PEGs.It has been found that the addition of 0.1% phosphoric acid can reduce the probability of pre-oligomer gels.When the PEG synthesized semi-blocked isocyanate grafted EAM with different molecular weights,the hydrophilicity of the aqueous resin increased from 7.71% to 43.01% with the increase of the molecular weight of PEG.At the same time,the hardness of the photocured film decreased and the light solidity decreased.The increase in time and the decrease in gel fraction.(3)We studied the effect of EAG synthesized by bisphenol A epoxy resin E44(EPE44)and phenolic epoxy resin F51(EP-F51)on the synthesis of aqueous modified epoxy acrylic resin.Because EP-F51 contains many epoxy structures,we open-loop esterification with acrylic acid at 40%,50%,60%,and 70% epoxy bonds,while grafting different side chains,compared with water-modified epoxy resins.Hydrophilic properties and physical and chemical properties. |
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