Study On UV-induced Polymerization Of Urushiol And Its Composites

Urushiol,the basis of lacquer,can be dried by laccase-catalyzed polymerization and aerobic oxidative polymerization.However,the procedure requires a long drying period and specific conditions(about 80-90%relative humidity at 20～30℃).Many efforts have been made to solve the problem by synthesis of rapidly curable urushiol-based compound. UV curing is a high-value,energy saving and environmental friendly technology.In this paper,the UV curing technology was used to dry urushiol and prepare its composites.The films of urushiol,urushiol-cuprum polymeric complexes and urushiol-lanthanum polymeric complexes were prepared under UV irradiation without any photoinitiator in the presence of air.PU/CdS nanocomposites and UV curable UEA were prepared.The mechanism of urushiol under UV irradiation and the properties of its composites were studied.The samples were characterized by Fourier transform infrared spectroscopy(FT-IR),electron spin resonance(ESR),TGA,XRD,SEM,TEM,UV-Vis and elemental analysis,etc.The results showed that urushiol can be cured whitin 2 min under UV irradiation without any photoinitiator in the presence of air.UV curing of urushiol was different in mechanism from lacquer polymerized by laccase-catalyzed oxidation.It was not an aerobic oxidative polymerization,but initiated by radicals under UV irradiation.The CdS nanoparticle had been homogeneously dispersed in PU/CdS nanocomposites.The films of urushiol and its composites had good thermo-stability and adhesion properties.