Synthesis and characterization of novel renewable tung oil-based UV-curable active monomers and bio-based copolymers

With the rapid development of industry and the growing shortage of fossil energy, tung oil has attracted much attention of researchers because of its environment-friendly and renewable advantages. In this work, we successfully synthesized two kinds of twig-oil-derived renewable UV-curable active monomers, tung-acid-maleic triacrylate (TOAH) and tung-maleic tetra-acrylate (TMPG). H-1 NMR and FT-IR results collectively revealed that the targeted active-monomers were successfully prepared. UV-curing kinetics of the films was studied by Photo-DSC, thermal properties of their cured films were investigated by dynamic mechanical analysis, thermogravimetric analysis and general performance of UV-curing films including acidic, alkaline resistance and boiling-water resistance were also investigated. Tensile properties of the cured films were also tested. Dynamic mechanical analysis demonstrated that the storage modulus and glass transition temperatures of the cured films increased while increasing the content of TMPG monomer. The crosslinking density of the cured copolymers also increased with the increasing content of TMPG monomer. TGA showed that the maximum thermal decomposition temperatures (T-max) of the cured copolymers were all above 420 degrees C. Tensile tests indicated that the tensile properties were better in the cured systems when the mixed films consisted of 5OTOAH/5OTMPG and 30% HDDA reactive diluent. Finally, all the results demonstrated that comparable balanced properties could be obtained by mixing these two bio-based monomers together.