Phenolic resin is ideal for production of circuit boards, laboratory counterparts, pool balls and as adhesives and coatings. Thus, it should be a more suitable biopolymer to replace phenol in formulation of phenolic resin when compared with other hardwood and softwood lignins that were used in previous studies. Under the optimum phenolate conditions, the phenolic hydroxyl content of lignin increased by 130%, whilst the methoxyl content was reduced by 68%. The sulfur contents of both lignin samples (original and isolated one) were the same (0.2%) and very low. The quick water immersion test used in this study was a very helpful method to rapidly evaluate the quality of the developed biobased resins. Choose products containing no formaldehyde; for example, those made with solid wood or stainless steel. Lignin as the most abundant natural aromatic polymer in the world, and with the back bone of phenyl propane units has exceptional capability to replace petroleum‐based phenol in PF resin.4, 5 However, up to now, to the best of our knowledge, phenol has been only replaced partially up to 50% when unmodified lignin was used, and addition of more than 50% lignin has been reported to have negative impact on the performance of prepared wood composites.4-12 At the commercial scale, in 1990 an OSB producer in North America was the first that blended 5% to 25% organosolv lignin with phenolic resin (powder) and reported no negative impact on properties of the produced OSB panels.7 In addition to the cost benefit of replacing phenol with lignin, they reported that application of lignin reduced dust in manufacturing facilities and improved environmental conditions on the site.7. Phenols occur either as colourless liquids or white solids at room temperature and may be highly toxic and caustic. You can taste and smell phenol at levels lower than those that are associated with harmful effects. Effluents and influents emanating from municipal waste treatment plants, and leachates from municipal solid waste landfill sites, are another source of phenolic compounds into water bodies. The physicochemical properties of the prepared resins and the mechanism of curing acceleration were investigated. The lignin sample used in this study was provided by POET LLC and is produced as a byproduct of bioethanol process through dilute acid pretreatment and enzymatic hydrolysis of corn stover. p‐Cresols have been identified in leachates from a municipal waste landfill site and are believed to originate from incineration residues. The prepared plywood samples were submerged into boiling water for 4 h, and then placed in the oven at 65 °C for 20 h before submerging them again in boiling water for another 4 h. The wet shear strengths of samples were evaluated right after the second 4 h boiling step. Thermal stability of the original and isolated lignin samples was measured using a TGA Q50 V20 instrument. In 1996, the installed capacity for the production of formaldehyde was estimated at 8.7 million tons per year. From Black Liquor to Green Material: Enzymatic Valorization of Pulp Industry Byproducts. Table 5 shows the dry and wet shear strengths of the plywood specimens made with commercial and lignin‐based adhesives. Since formaldehyde exists predominantly in solution as a dynamic equilibrium of methylene glycol oligomers, the concentration of the reactive form of formaldehyde depends on temperature and pH. While viscosity can be readily controlled, efforts are underway to address the slightly higher free formaldehyde content in lignin‐based resin without negatively affecting the final performance of composite products. 31P NMR spectra of isolated lignin sample. The gelation time of each resin was also measured following the procedure reported by Pizzi and Mittal.10 About 1 g of resin was placed in a glass test tube and immersed in a beaker filled with boiling water. Extrusion of Solid Wood Impregnated with Phenol Formaldehyde (PF) Resin: Effect of Resin Content and Moisture Content on Extrudability and Mechanical Properties of Extrudate. Molecular size determination of the original lignin sample was not possible because it was not soluble in NaOH. DSC graphs of lignin‐based (green) and commercial (red) phenolic adhesives. The percent ash content of isolated lignin sample was measured after calcination of the sample in a Sybron Thermolyne Furnatrol muffle furnace at 525 °C for 4 h, following the procedure described in TAPPI T 211 om‐93 standard test method. Free and hydrolyzed formaldehyde (water extraction method) BS EN 14184-2 Textiles. The maximum SEL replacement percentage of phenol reached 70 wt%, and the properties of adhesives and plywoods met the Chinese National Standard (GB/T 14732-2006) for … This source category includes, but is not limited to, phenol-formaldehyde, phenol-furfural and resorcinol-formaldehyde. Based on the NMR analysis results, our assumption was that this lignin should have much higher reactivity toward formaldehyde.