| As a renewable bio-based raw material,soybean oil(SBO)is attracting increasing more attention of coatings industry for its advantageous characteristics of green environmental protection and low price.Ultraviolet(UV)curing technology become a viable alternative to the traditional solvent-based coating production process due to its energy saving,high efficiency and low pollution.Combining the characteristics of soybean oil and UV technology to prepare bio-based photocurable oligomers has great research significance.In this paper,aiming to synthesize cationic photocurable soybean oil-based oligomers by green,efficient and convenient synthesis,soybean oil-based urethane modified epoxy resins(SBO-URE)is prepared by thiol-ene click reaction and carbamate reaction.Futher more,SBO-URE improve the shortcoming of epoxidize soybean oil(ESO)in application and expand the application of soybean oil-based oligomers in photocuring technology.The main researches and conclusions of this paper are as follows:1.SBO-polyols was prepared by reacting mercaptoethanol(MCH)with SBO,and then the precursor synthesized by isophorone diisocyanate(IPDI)and glycidol was grafted to obtain the target product SBO-URE.The effects of feed ratio and reaction temperature on the synthesis were investigated.The molecular segment structure of the SBO-URE was characterized by FT-IR,~1H NMR and TGA.Studied on kinetics of cationic UV-curing process of SBO-URE by real time-FTIR.The performance of SBO-URE cured films were characterized by DSC,TGA and tensile strength test.2.SBO-URE was used for thoughening 3,4-Epoxycyclohexylmethyl-3',4'-epoxy-cyclohexanecarboxylate(ECC).The photocuring kinetics of ECC/SBO-URE resin was studied and photoinitiators and photosesit izer system were optimized.DMA characterized the storage modulus,damping properties and glass transition temperature of ECC/SBO-URE and ECC/ESO cured films.TGA,tensile strength test and impact strength test characterized the heat resistance and mechanical properties of the cured films respectively.The mechanical properties showed that SBO URE had good toughening effect to ECC.The microstructure of the fracture surface of the cured films was observed by SEM,and the mechanism of the toughening effect was analyzed in the SEM images.3.SBO-URE was used for thoughening and anti-shrinkage modifying liquid photosensitive resin NCM-3721C for 3D printing.The viscosity,UV-visible absorbance and photocuring kinetics of NCM-3721C/SBO-URE resin were characterized.The properties of the 3D printed specimens were characterized by TGA,impact strength test and tensile strength test.The impact strength test results showed that SBO-URE had excellent toughening effect.DMA characterized the thermomechanical properties of the specimens.Measurement results of resin's shrinkage rate showed that adding SBO-URE can resist shrinkage effectively.The microscopic morphology of the specimens'fracture surface was observed by SEM.The model for testing 3D printing accuracy was demonstrated. |
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