Laccase‐catalyzed polymerization drying of Chinese lacquer sap with TiO₂ nanoparticles

Abstract

Nano‐TiO2/lacquer hybrid coatings are prepared by the blend of nano‐TiO2 and lacquer sap. Nano‐TiO2 particles are involved in the laccase‐catalyzed polymerization process of urushiol, which improves the properties of lacquer film. With increasing nano‐TiO2 from 0 to 5 wt %, the drying time of lacquer film to reach hardened dryness decreases from >12 h to 8 h 30 min under 30 °C and 80% relative humidity. Gel permeation chromatography analysis shows that the addition of nano‐TiO2 accelerates the polymerization of urushiol. It is also related to the formation of TiOC bonds due to the reaction between nano‐TiO2 and the radicals produced by laccase‐catalyzed oxidation. The pencil hardness, flexibility, and adhesion of hybrid lacquer film can be improved and reach 4H, 1 mm, and grade 2, respectively. Its inhibition rate against Escherichia coli and Staphylococcus aureus increases from 22.6% and −21.4% to 49.2% and 67.8%, respectively. Furthermore, nano‐TiO2 hybrid lacquer films also possess higher thermo‐stability than the raw lacquer film. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45865.

Synthesis of a Compound Phosphorus-Nitrogen Intumescent Flame Retardant for Applications to Raw Lacquer

“…The stage was very similar to the stages of some polysaccharides reported in [3,24]. [13,21,22]. Comparing FT-IR spectra of RL and RL/IFR, it is distinctive that RL and RL/IFR have comparable absorption peaks with slightly different strength and width.…”

“…The C-N stretching vibrations of melamine are identified between 1652 and 1440 cm −1 and the characteristic peaks of FR-1 and FR-2 occur at 1256 cm −1 (P=O), 1075 cm −1 (P-O symmetrical expansion), and 880 cm −1 (P-O asymmetric expansion) [21]. [13,21,22]. Comparing FT-IR spectra of RL and RL/IFR, it is distinctive that RL and RL/IFR have comparable absorption peaks with slightly different strength and width.…”

“…The results are ascribed to the vapor, N 2 and CO 2 (i.e., flame resistant air types) that are produced during the thermal decomposition of IFR, and then sealed in a thick char layer, which subsequently making the char layer in an intumescent state. In the meanwhile, a tremendous amount of gaseous products are released from the pores over the char layer, which in turn puts out the fire efficiently, known as the blow-out effect [22]. At last, with 30 wt% IFR, there is a greater flame retardant content for the RL/IFR membranes, facilitating the formation of chambers over the char layer surface, as shown in Figure 6c.…”

“…FT-IR of raw lacquer and RL/IFR as related to different proportions. As for RL's spectra, the absorption peaks of urushiol's C-O-H group occur at 3439, 1363, 1275, and 1150 cm −1 , which correspond to the stretch vibration of O-H, β O-H, γ O-H, and C-O, respectively[13,21,22]. Comparing FT-IR spectra of RL and RL/IFR, it is distinctive that RL and RL/IFR have comparable absorption peaks with slightly different strength and width.…”

Facile one-pot synthesis of silver nanoparticles encapsulated in natural polymeric urushiol for marine antifouling

“…Urushiol, a natural product from raw lacquer that has a catechol derivative with a linear alkenyl group, 21 which not only has bactericidal and antioxidant properties, 22 but also has excellent corrosion resistance and water resistance. Urushiol can be an excellent choice for coatings used in harsh environments and bio-corrosive protection caused by microbial aggregation.…”