Synthesis And Properties Of Urushiol-based Resin And Its Composite Coatings

Raw lacquer is a kind of rich resources of forest resources in China,which has a history of thousands of years of use in our country.Urushiol is the main film forming material which could be oxidized by laccase catalytic,and then cured under natural state into a membrane,because of its excellent properties,which was deeply loved by people.But its strong sensitization,the viscosity is unfavorable construction,natural drying film-forming long,paint film brittle faults and so on are always restricts the use of its own.In this paper,some green and environmental modified urushiol ramification such as uv-curable paint,coating,and antibacterial coating were prepared,and their performance were studied.1.Two novel unsaturated polyester resins named UA and UAE were synthesized from urushiol(U),acryloyl chloride(AC)and allyl glycidyl ether(AGE)as raw material via esterification and epoxy ring-opening reaction.Its chemical structures were characterized by Fourier transform-infrared analysis and proton nuclear magnetic resonance.Then the two allyl resin monomers were mixed at different weight ratios and cured under UV light.The results indicated that all the cured films had good flexibility,impact resistance and adhesion,and UAE cured film had best hardness which reached up to 2 H;SEM showed that UA cured film and UAE cured film both had best smooth surface;Thermogravimetric analysis(TG)showed that all the cured films had good thermal stability,the heating initial decomposition temperatures were all above 340 ?.2.Urushiol glycidyl ether(UGE)was synthesized by using urushiol(U)and epoxy chloropropane as raw material.The optimum reaction conditions were determined through investigated the reaction material ratio,the reaction time,reaction temperature,catalyst dosage and sodium hydroxide dosage on the UGE epoxy value.FT-IR,1H-NMR and 13C-NMR analysis results showed that the target product has been successfully synthesized,the GPC of UGE was 478;Thermogravimetric analysis(TG)showed that UGE owned good thermal stability,the heating initial decomposition temperatures was above 370 ?.The epoxy value of UGE was up to 0.309 mol/100 g using aceton hydrochloride method,and the viscosity of UGE was 12.8 mPa·s(25 ?).3.Urushiol glycidyl ether(UGE)was synthesized from urushiol(U)via epoxy reaction.Then three kinds of modified coatings film were synthesized from UGE and tannin acid(T),urushiol(U)and diethylenetriamine(DETA),respectively.The performance of tannin acid modified urushiol glycidyl ether coating(T-UGE)was studied with the addition of tannin acid,when the content of tannins acid was 30% of urushiol glycidyl ether,the paint film was best,and hardness could be up to 2 H;By comparing the comprehensive performance of three kinds of paint film,the results showed that tannin acid modified urushiol glycidyl ether coating film(T-UGE)had excellent tensile strength,which was up to 11.84 MPa;Thermogravimetric analysis(TG)showed that T-UGE owned good thermal stability,the heating initial decomposition temperatures was up to 391.6 ?,and the maximum weightlessness rate was 15.13 %/min.4.Urushiol nanosilver antibacterial coating was prepared by adding separately 0.25%?0.50%?0.75%?1.00%?1.25% nanometer Ag antimicrobial into urushiol glycidyl ether water-based paint which was modified by tannin.We investigated the best addition of nanometer silver antibacterial agent by using bacteriostatic ring size as investigation object and the oxford cup method was used to determine the bacterio static activity of antimicrobial coating.The results indicated that the preparation of antibacterial coatng on Escherichia coli,Monilia albican,Staphylococcus aureus,Streptococcus pneumoniae had certain inhibitory effect.When the content of nanometer Ag antimicrobial was up to 0.75%,the antibacterial effect was best to escherichia coli and staphylococcus aureus,the diameters of bacteriostatic ring were up to 18.6mm and 15.8mm respectively;when the content of nanometer Ag antimicrobial was up to 1.00%,the antibacterial effect was second to candida albicans and streptococcus pneumoniae,the diameters of bacteriostatic ring were up to 12.6mm and 11.6mm respectively.