Phenol-formaldehyde/silica hybrid gel with hydrophobic character, high porosity, and thesmall pore size mean was prepared via sol-gel polymerization under solvent saturated vaporatmosphere and was dried by ambient drying method. The silica sols were prepared based onTetraethoxysilane (TEOS) and Methyltrimethoxysilane (MTES) as hydrophilic and hydrophobicprecursors, respectively. Phenol-formalde...

in this study, hybrid of phenol formaldehyde-fish glue was used to replace the chemical resin in plywood manufacturing. for this purpose, fish glue was applied at three levels including 0, 10 and 20 percent based on the dry weight of resin. physical and mechanical properties of manufactured plywoods were measured. thickness swelling after 2 and 24 hours immersion in tap water, bending strength,...

Humins are low-value-added byproducts from the biomass acid hydrolysis process. In the present work, humins were first employed as a phenol replacement for synthesis of modified phenol-formaldehyde adhesives through a two-step process. In this process, humins were first utilized to obtain alkaline soluble products, mainly consisting of phenolics, through a hydrothermal process. The obtained alk...

MO XF, FAN DB, QIN TF & CHU FX. 2015. Curing characteristics and adhesion performance of phenol–formaldehyde resins with composite additives. The curing characteristics of cure-accelerated phenol–formaldehyde resins with composite additives were investigated by differential scanning calorimetry analysis and gelation test. The pot lives and adhesion performances of phenol–formaldehyde resins wer...

Different resol phenol-formaldehyde prepolymer resins have been synthesized with different formaldehyde / phenol ratios. The phenolic resin composition depends on monomer ratio, catalyst, reaction conditions, and residual free monomers. Temperature and pH conditions under which reactions of phenols with formaldehyde are carried out have a profound effect on the characteristics of the resulting ...

Many industrial activities utilise formaldehyde as a key chemical in organic synthesis including: synthesis of special chemicals such as pentaerythritol and ethylene glycol, synthetic resins, paper products, medicinal products and drugs and others, too numerous to mention. Therefore, effluents arising from these applications may contain significant amounts of formaldehyde. In a biodegradation e...

Formaldehyde and phenol biodegradation during the denitrification process was studied at lab-scale, first in anoxic batch assays and then in a continuous anoxic reactor. The biodegradation of formaldehyde (260 mgl(-1)) as single carbon source and at phenol concentrations ranging from 30 to 580 mgl(-1) was investigated in batch assays, obtaining an initial biodegradation rate around 0.5g CH(2)Og...

Organosolv wheat straw lignin extracted using the CIMV process is a linear, low molecular weight, and natural phenolic oligomer. In this study, organosolv wheat straw lignin was tested as a substitute for 50% to 70% of the phenol in a phenol-formaldehyde-resol resin. The lignin was used without any chemical modification in a one-step synthesis reaction. Parameters such as reaction time and form...

Lignin modified phenol formaldehyde wood adhesives have been prepared by replacing phenol with the groundnut shell lignin (GNSL) at varying weight percentages. The optimization of weight percent incorporation of GNSL was carried out in respect to mechanical properties. It was found that a maximum of up to 50 wt.% of phenol in the phenol formaldehyde (PF) adhesive can be substituted by GNSL to o...

To prepare a low-formaldehyde soy-based adhesive with good water resistance, phenol-formaldehyde modified with glutaraldehyde (PFG) with lower free phenol and free formaldehyde contents was used to cross-link the soy-based adhesive. The results showed that the mechanical properties and water resistance of plywood prepared with soy-based adhesive with PFG was better than that of plywood with the...