Synthesis And Application Of Resins Based On Liquefied Product From Chinese Fir With Phenol

In order to release dependency of synthesizing phenol-formaldehyde resins on petrol and its ramification, reduce cost, widen application fields and improve the utilization of biomass materials, we carry out the research on preparation of resins from liquefied wood in phenol in presence of sulfuric acid. In this paper, effects of resinfication factors on chemical and bonding properties of resins were systemically studied; optimum hot-press processing parameters were defined by orthogonal test; changes of groups and mechanism of reaction were analysed by FTIR; cost of liquefied Chinese Fir resins was also calculated.The results are as follows:1) With increasing F/P molar ratio, free phenol content of resin remarkablely decreased on both liquefaction condition (wood/phenol=1:2, 1:3), free formaldehyde content linearly increased; with rise of NaOH/P molar ratio, free phenol content of resin from wood/phenol 1:2 liquefied product increased, but that of resin from wood/phenol 1:3 liquefied product showed no obvious changes; adding alkalis was good for reducing free formaldehyde content of resin; both free phenol and formaldehyde of resin obviously decreased with enhancing resinification temperature.2) Bond strength decreased with adding formaldehyde then were improved, and showed minimum value at F/P molar ratio 1.8; bond strength increased with rise of NaOH/P molar ratio, but excess alkalis would lead to bond strength dropping; with enhancing resinification temperature, bond strength of the resin from wood/phenol 1:2 liquefied product arrived at the maximum at 80℃ and that from wood/phenol 1:3 liquefied produc reached the minimum at 85℃; results showed optimum formation of liquefied Chinese Fir resin (LWR) were wood/phenol 1:2, F/P molar ratio 1.8, NaOH/P molar ratio 0.7, resinification temperature 80℃.3) The optimum hot press parameters for LWR were as follow: hot-press temperature 125℃,press 1.0MPa, hot-press time 1.0min/mm, quantity of solidified agent 0.1%.4) The Physics and Chemistry Performance of liquefied Chinese Fir resin was similar to that of traditional PF resins and met the requirement of GB/T 14732-93. Bond strength of the poplar three-layer plywood bonded with LWR satified the demands of I level. Free formaldehyde content of plywood was 0.2mg·L^-1 which is lower than the E₀ level set by GB 9486-2004. Phenolated reaction between phenol and wood conponets during liquefaction in presence of sulfuric acid; crystal lattice of cellulose was destroyed; hemicellulose and lignin were degraded to low molecule substance; FTIR of LWR showed typical absorbing peaks as PF resins. The cost of LWR was 15% lower than that of traditional PF.