Preparation and application of lignin-modified phenolic resin adhesive
Phenolic resin is an excellent adhesive material,but it has drawbacks such as the emission of toxic sub-stances and the use of non-renewable raw materials.To effectively address these issues,a method of modifying phe-nolic resin with lignin is proposed.Lignin is modified under alkaline conditions,and then lignin-based phenolic resin is synthesized by the ortho-para substitution reaction of the modified lignin with phenol.The characteristics of pheno-lic resins prepared with different lignin substitution rates are investigated using Fourier transform infrared spectroscopy(FTIR)and ultraviolet spectrophotometry(UV),and the solid content and bonding strength of the modified adhesives are systematically tested.Through single-factor experiments,the optimal experimental conditions are determined to be an aldehyde-phenol mass ratio of 1.5:1,a lignin substitution rate of 30％,and an alkali dosage of 15％.Under these conditions,the solid content of the prepared adhesive is 52.33％,and the bonding strength reaches 2.21 MPa.Wood-based panels are bonded using kenaf lignin-modified phenolic resin,industrial lignin-modified phenolic resin,and un-modified phenolic resin adhesives,and the bonding strength of different panels is tested.The results show that the bonding strength of industrial lignin-modified phenolic resin is 56％of that of unmodified phenolic resin,while the bonding strength of kenaf lignin-modified phenolic resin is 79％of that of unmodified phenolic resin,indicating that the prepared kenaf lignin-based phenolic resin is superior to industrial lignin-based phenolic resin.
国家科技期刊平台
NSTL
万方数据
