Characterization and comparison of Asian lacquer saps

Five kinds of Asian lacquer saps, Thailand raw and kurome, China raw and kurome, and Vietnam raw lacquer, were characterized by IR, UV resistance, viscosity, rigid-body pendulum physical property-testing and NMR measurements. The results showed that although Thailand lacquer has the highest oligomer and polymer content, its drying speed is the slowest, and it has the best UV resistance. In addition, the monomer, dimer, trimer, and tetramer fractions of thitsiol of Thailand raw lacquer were separated by HPLC and analyzed by NMR spectroscopy. Almost all proton and carbon NMR peaks were assigned, and the structure of thitsiol was confirmed.