Thermal stability and thermal degradation kinetics of urea-formaldehyde resin modified by sodium lignosulfonate

In this paper, an environmentally friendly urea-formaldehyde resin (UF) was prepared by using sodium lignosulfonate (SL) as a modifier. According to the basic properties of the resin, the strength of the plywood and the formaldehyde emission, the optimum addition amount of SL was determined. At the same time, the thermal curing and thermal degradation behavior of the resin were studied. The results show that the addition of SL can significantly reduce the formaldehyde emission of plywood. When the addition amount of SL was 1%, the wet bonding strength and formaldehyde emission of SL-modified UF (SL-UF) resin were 1.28 MPa and 0.35 mg<middle dot>L-1, respectively, which were 23% higher and 71% lower than those of UF resin. Moreover, the initial curing temperature of SL-UF resin is lower, but the thermal curing activation energy is higher. SL also has a significant effect on the thermal degradation performance of UF resin. SL is a modifier that can effectively improve the performance of UF.