Eco-friendly phenol formaldehyde resin wood adhesive from bagasse lignin liquefaction

Liquefaction products were prepared using bagasse lignin and phenol as raw materials and sulfuric acid as catalyst. Liquefaction products as a substitute for phenol were applied to synthesize bagasse lignin-based phenol formaldehyde (BLPF) resin. Compared with the deep red phenol formaldehyde (PF) resin, the appearance of BLPF resin was dark brown, its solid content was 50.97%, swelling degree was 78.16%, pH was 9.36, storage life was 25–30 d, all of these parameters were lower than PF resin. The introduction of liquefaction products has undermined the bonding properties of resin but enhanced its environmental performance. Compared with the plywood made with PF resin, the plywood made with BLPF resin had lower dry bonding strength (1.99 ± 0.17 MPa, decreased by 0.29 MPa) and wet bonding strength (1.50 ± 0.11 MPa, decreased by 0.24 MPa). Besides, the formaldehyde emission of BLPF resin decreased from 1.134 to 0.641 mg/L, and the weight loss increased from 10.81% to 12.49%. Finally, the functional mechanism of liquefaction products of bagasse lignin on BLPF resin was discussed through the utilization of various precision instruments. •Liquefied products of bagasse lignin are used for modifying phenol formaldehyde resin.•Fundamental properties of modified phenol formaldehyde resin are discussed.•Introduction of liquefied products improved the environmental performance of resin.•New utilization approach of bagasse lignin.