Temperature-sensitive microcapsules modification treatment to reduce formaldehyde emission from wood-based panels

The formaldehyde emission performance of wood-based panels treated with temperature-sensitive microcapsules was evaluated in this study. Formaldehyde scavenger-filled microcapsules were synthesized by the emulsion-solvent method using ethylcellulose and poly(N-isopropylacrylamide) (PNIPAM) as shell materials containing urea. The results demonstrated that the temperature-sensitive microcapsules exhibited perfect core-shell structures at a core/shell/PNIPAM ratio of 2:2:1. The loading capacity and loading efficiency of the functional core material of the microcapsules reached 33% and 59%, respectively. Compared with untreated panels, panels based on the temperature-sensitive microcapsule scavenger had better performance in controlling free formaldehyde emissions, the formaldehyde emission of treated panels decreased by 42% and 41% at room temperature and 40 degrees C, respectively. The results indicated that the reason why the woodbased panels had a long-term low-level emission was that the microcapsules showed different release behaviour at different temperature, so they have different release paths and release principles.