scholarly journals Ecofriendly wood adhesives from date palm fronds lignin for plywood

BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 4106-4125
Author(s):  
Hiba Ibrahim Huzyan ◽  
Alia Abdul Aziz ◽  
M. Hazwan Hussin
Keyword(s):  
Date Palm ◽  
Phenol Formaldehyde ◽  
Wood Adhesive ◽  
Mechanical Tests ◽  
Solid Content ◽  
Scanning Calorimetry ◽  
Molar Ratios ◽  
13C Nuclear Magnetic Resonance ◽  
Soda Lignin ◽  
Palm Fronds

Utilization of lignin phenol glyoxal (LPG) resins was studied as a potential alternative for phenol formaldehyde (PF) resins. Lignin was extracted by alkaline pulping processes (kraft and soda) from date palm fronds (DPF) and was used as an alternative for phenol in LPG resins. The isolated lignin samples were characterized using complementary analyses that included Fourier transform infrared (FTIR) spectroscopy, 13C nuclear magnetic resonance (NMR) spectroscopy, thermal stability, thermogravi-metric analysis (TGA), and differential scanning calorimetry (DSC). Kraft lignin phenol glyoxal (KLPG) and soda lignin phenol glyoxal (SLPG) resins also were characterized in terms of solid content, viscosity, and gel time. Finally, physico-mechanical tests were performed on plywood panels that were treated with different molar ratios of LPG resins. The results revealed that 50% (w/w) KLPG resin resulted in higher tensile strength (65.3 MPa) than PF resin (58.57 MPa), which was potentially attributed to the higher amount of phenolic groups compared to soda lignin. Therefore, the substitution of DPF lignin in LPG resins enhanced the adhesive in terms of its chemical and mechanical properties, enabling it to produce a more environmentally friendly wood adhesive.

Paper mill sludge as a component of wood adhesive formulation

Holzforschung ◽  
2007 ◽  
Vol 61 (6) ◽  
pp. 688-692 ◽  
Author(s):  
Xinglian Geng ◽  
James Deng ◽  
Shu Yin Zhang
Keyword(s):  
Phenol Formaldehyde ◽  
Paper Mill ◽  
Wood Adhesive ◽  
Wood Failure ◽  
Infrared Spectrometry ◽  
Scanning Calorimetry ◽  
Adhesive Properties ◽  
Paper Mill Sludge ◽  
Potential Component ◽  
Adhesive Formulation

Abstract Three major types of paper mill sludge, primary sludge (PS), secondary sludge (SS) and de-inking paper sludge (DPS) were characterized and evaluated as adhesive fillers. Plywood panels were made of formulations with phenol formaldehyde (PF) and sludges. Panels with PF/PS and PF/SS formulations had higher dry and wet shear strengths than those made with PF/Cocob® formulation. All wood failure values were comparable. Dry and wet shear strengths of the panels with PF/DPS formulation were comparable to those of the PF/Cocob® panels (with Cocob® as a commercial filler), but the former displayed a much lower wood failure value. Owing to this fact and its high ash content, DPS was not evaluated further as a potential component of adhesive formulations. Compared with SS, PS resulted in higher dry and wet shear strengths and higher wood failure values. However, granular SS was easier to disperse into the resin component than fibrous PS, and the PF/SS formulation was more easily dispensed on aspen veneer sheets than the PF/PS formulation. SS alone displayed adhesive properties with 0.87 MPa of dry shear strength, but PS alone did not exhibit any bond strength. PS and SS were further evaluated for their general thermal behavior and major functional groups using differential scanning calorimetry and Fourier transform infrared spectrometry, respectively.

Softwood Bark Pyrolysis Oil-PF Resols. Part 2. Thermal Analysis by DSC and TG

Holzforschung ◽  
2002 ◽  
Vol 56 (3) ◽  
pp. 273-280 ◽  
Author(s):  
C. Amen-Chen ◽  
B. Riedl ◽  
C. Roy
Keyword(s):  
Phenol Formaldehyde ◽  
Condensation Reaction ◽  
Cure Kinetics ◽  
Phenol Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Pyrolysis Oil ◽  
Scanning Calorimetry ◽  
Molar Ratios ◽  
Model Free ◽  
Pyrolysis Oils

Summary Cure behavior of resins formulated with petroleum phenol replaced by 25 and 50 wt% of softwood bark-derived pyrolysis oils, using various formaldehyde to phenolics molar ratios and alkalinity content, was characterized by Differential Scanning Calorimetry (DSC). Kinetic parameters were obtained by the Borchart-Daniels method and the model-free (Vyazovkin) method. Resins containing up to 50% by wt of pyrolysis oils had slower cure kinetics and lower extent of condensation reaction compared to a neat laboratory made phenol-formaldehyde resin. However, very similar kinetic curing behavior to the standard resins was found for resols having 25% by wt of the petroleum phenol replaced by the pyrolysis oils. Thermogravimetric analysis (TG) of cured pyrolysis oil-PF resins has been done under nitrogen and air environments at a constant heating rate. Thermal behavior of resins containing pyrolysis oils differed depending on the nature of the purge gas used in TG. Increasing the amount of pyrolysis oils decreased the thermal resistance of the experimental resins.

scholarly journals Preparation, Characterization of Propargyl Terminal Polybutadiene and Its Crosslinked Elastomers Properties

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 748
Author(s):  
Jinxian Zhai ◽  
Xiaoyan Guo ◽  
Nana Liu
Keyword(s):  
Mechanical Tests ◽  
Target Product ◽  
Scanning Calorimetry ◽  
Glass Transition Temperatures ◽  
Molar Ratios ◽  
Cuaac Reaction ◽  
Lower Viscosity ◽  
End Capping ◽  
Thermal Stability Of

Propargyl terminal Polybutadiene (PTPB) was successfully prepared through hydroxyl terminal polybutadiene (HTPB) end-capping modification. The FTIR and 13C NMR results indicated that the HTPB terminal hydroxyl was thoroughly replaced and yielded the target product, PTPB, with a theoretical propargyl content of 0.66 mmol g−1. In comparison with HTPB, PTPB has a lower viscosity. Using 1,6-diazide hexane as a curing agent, polytriazole crosslinked polybutadiene (PTriPB) elastomers with various functional molar ratios (R) were prepared by CuAAC reaction, and the glass transition temperatures of the resultant PTriPB elastomers were approximately −75 °C, measured by differential scanning calorimetry (DSC), nearly independent of elastomer R values. Mechanical tests indicated, that with the increase in R, the mechanical properties of PTriPB elastomers exhibit a parabolic dependence on R. In addition, the thermal stability of PTriPB elastomers were also studied. The findings revealed some fundamental features of polytriazole crosslinking elastomer prepared by CuAAC reaction.

scholarly journals Synthesis of lignin-based phenol-formaldehyde adhesive - A sustainable alternative to petrochemical

2021 ◽  
Vol 13 (3) ◽  
pp. 48-57
Author(s):  
Thi Nhu Y Nguyen ◽  
Thi Yen Nhi Nguyen ◽  
Thi Minh Thu Tran ◽  
Thi Ven Nguyen ◽  
Nguyen Phuong Lan Tran ◽  
...  
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Bending Strength ◽  
Phenol Formaldehyde ◽  
Tensile Modulus ◽  
Mekong Delta ◽  
Solid Content ◽  
Synthesis Process ◽  
Scanning Calorimetry ◽  
Synthetic Process

This study is to investigate the capability of producing lignin-based phenol-formaldehyde adhesive (LBPFA) with lignin derived from coir pith collected in the Mekong Delta, Viet Nam. The LBPFA synthetic process underwent non chemical modifications to minimize petrochemicals and energy. Effective factors as reaction time, reaction temperature and various lignin contents of phenol substitution were examined. Physical, chemical and thermal properties containing formaldehyde content, viscosity, solid content, Fourier transformed infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), tensile strength, tensile modulus and tensile strain were conducted. LBPFA was successfully synthesized at various levels of lignin contents substituting for phenol. The LBPFA’s parameters were in accordance with GB/T14372-2006 standard. The optimum reaction time, reaction temperature and lignin replacement content for LBPFA synthesis process were identified at 180 minutes, 900C and 40% wt/wt, respectively. The LBPFA showed the highest dry and wet tensile strengths of 14.42 MPa and 7.66 MPa on wooden boards compared to corresponding figures of commercial resin with 2.98 MPa and 0 MPa, respectively. For plywood, bending strength shown in LBPFA and commercial adhesive were 15.97 MPa and 20.16 MPa, respectively.

Softwood Bark Pyrolysis Oil-PF Resols. Part 3. Use of Propylene Carbonate as Resin Cure Accelerator

Holzforschung ◽  
2002 ◽  
Vol 56 (3) ◽  
pp. 281-288 ◽  
Author(s):  
C. Amen-Chen ◽  
B. Riedl ◽  
X.-M. Wang ◽  
C. Roy
Keyword(s):  
Mechanical Properties ◽  
Propylene Carbonate ◽  
Phenol Formaldehyde ◽  
Cure Kinetics ◽  
Pyrolysis Oil ◽  
Scanning Calorimetry ◽  
Cure Reaction ◽  
Resin Solid ◽  
Molar Ratios ◽  
Pyrolysis Oils

Summary Phenol-formaldehyde (PF) resols were prepared with different proportions of phenol replaced with softwood bark pyrolysis oils under varying formaldehyde to phenolics molar ratios and sodium hydroxide contents. Propylene carbonate (PC) was added to these adhesives to improve the cure of resins. The cure behavior was characterized by differential scanning calorimetry (DSC). Cure kinetics and amount of cure of the experimental resin were improved by adding PC to the resins. Low amounts of PC were used (less than 1.5% of PC on a resin solid basis) to avoid premature gelling of the adhesives. Results obtained by DSC suggested that PC catalyzed the resin cure reaction and also participated in resin cross-linking reactions. Low percentages of PC, 0.5 and 1% on a resin solid basis, were added to the experimental resins for bonding strandboards. These addition levels did not significantly improve mechanical properties of strandboards. It is concluded that a PC addition level of more than 1% by wt (on a resin solid basis) should be used to modify the mechanical properties of panels bonded with pyrolysis oil-PF resins.

scholarly journals A novel wood adhesive based on yeast hydrolysate

BioResources ◽  
2019 ◽  
Vol 14 (3) ◽  
pp. 6015-6024
Author(s):  
Mingyang Bai ◽  
Yepeng Huang ◽  
Suzhen Huang ◽  
Shujie Wang ◽  
Wanjuan Chen ◽  
...  
Keyword(s):  
Epoxy Group ◽  
Sodium Dodecyl ◽  
Wood Adhesive ◽  
Diglycidyl Ether ◽  
Solid Content ◽  
Curing Temperature ◽  
Scanning Calorimetry ◽  
Adhesive Properties ◽  
Yeast Hydrolysate ◽  
Ring Opening Reaction

Due to certain problems with petroleum-based products, the development of a renewable and green adhesive is urgent and important. Yeast hydrolysate, which contains more than 55% protein, possesses many advantages in its source (it originates from yeast as opposed to petroleum) and environmental protection. In this work, a wood adhesive based on yeast hydrolysate was developed through the addition of sodium dodecyl sulfate (SDS), polyvinyl alcohol, and ethylene glycol diglycidyl ether (EGDE) to improve properties of the yeast hydrolysate adhesive via the epoxy group in EGDE. The influence of EGDE on the adhesive properties (density, viscosity, solid content, bonding strength, and curing temperature) was investigated. The thermal property and changes in molecular structure during curing were characterized via differential scanning calorimetry and Fourier transform infrared spectroscopy, respectively. These results indicated that a ring-opening reaction between the epoxy group of EGDE and the active group had an important influence on the properties.

scholarly journals Structural Characterization of Cure Bio-based Phenol Formaldehyde Wood Adhesive

2020 ◽  
pp. 12-19
Author(s):  
Y. B. Olayiwola
Keyword(s):  
13C Nmr ◽  
Liquid State ◽  
Phenol Formaldehyde ◽  
Wood Adhesive ◽  
Resin System ◽  
Nmr Study ◽  
13C Nmr Analysis ◽  
13C Nuclear Magnetic Resonance ◽  
Phenolic Components

Bio-phenol formaldehyde (BPF) resole resins were characterized by liquid-state 13C Nuclear Magnetic Resonance (NMR) spectroscopy. The liquid 13C NMR analysis indicated that the condensation reactions between the bark phenolic compounds and the formaldehyde occurred during the synthesis of the resins. Methylene ether bridges in the resins were more pronounced in the BPF resin when compared to the PF resin system. The liquid-state 13C NMR study revealed significant differences in the resins structures induced by the inclusion of bark-phenolic components. The bark-phenolic components favored the formation of para-ortho methylene linkages in the BPF resins and also enhanced the cure rate of the BPF resin system.

scholarly journals Weathering Stability and Durability of Birch Plywood Modified with Different Molecular Weight Phenol-Formaldehyde Oligomers

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 175
Author(s):  
Juris Grinins ◽  
Vladimirs Biziks ◽  
Brendan Nicholas Marais ◽  
Janis Rizikovs ◽  
Holger Militz
Keyword(s):  
Uv Light ◽  
Phenol Formaldehyde ◽  
Wood Decay ◽  
Soft Rot ◽  
Solid Wood ◽  
Solid Content ◽  
Molecular Weights ◽  
Weathering Processes ◽  
Commercial Resin ◽  
D 20

This study investigated the effect of phenol-formaldehyde (PF) resin treatment on the weathering stability and biological durability of birch plywood. Silver birch (Betula pendula) veneers were vacuum-pressure impregnated with four different PF resins with average molecular weights (Mw) of 292 (resin A), 528 (resin B), 703 (resin C), and 884 g/mol (resin D). The aging properties of PF resin modified birch plywood were analyzed using artificial weathering with ultraviolet (UV) light, UV and water spray, and weathering under outdoor conditions. The same combinations of PF-treated plywood specimens were then tested in soil-bed tests to determine their resistance against soft-rot wood decay. It was not possible to compare weathering processes under artificial conditions to processes under outdoor conditions. However, the weathering stability of birch plywood treated with PF resins A, B, and C, scored better than plywood treated with commercial resin D (regardless of solid content concentration [%]). Results from unsterile soil bed tests showed improvements in resistance to soft-rot wood decay compared to untreated plywood and solid wood. Mass loss [%] was lowest for birch plywood specimens treated with resin of highest solid content concentration (resin D, 20%). Provisional durability ratings delivered durability class (DC) ratings of 2–3, considerably improved over untreated solid wood and untreated birch plywood (DC 5).

scholarly journals Co-Amorphous Formulations of Furosemide with Arginine and P-Glycoprotein Inhibitor Drugs

Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 171
Author(s):  
Marika Ruponen ◽  
Konsta Kettunen ◽  
Monica Santiago Pires ◽  
Riikka Laitinen
Keyword(s):  
Storage Conditions ◽  
Scanning Calorimetry ◽  
Glycoprotein P ◽  
Molar Ratios ◽  
P Glycoprotein ◽  
Permeation Studies ◽  
Poorly Soluble ◽  
Biopharmaceutics Classification ◽  
Permeability Assay ◽  
Simultaneous Dissolution

In this study, the amino acid arginine (ARG) and P-glycoprotein (P-gp) inhibitors verapamil hydrochloride (VER), piperine (PIP) and quercetin (QRT) were used as co-formers for co-amorphous mixtures of a Biopharmaceutics classification system (BCS) class IV drug, furosemide (FUR). FUR mixtures with VER, PIP and QRT were prepared by solvent evaporation, and mixtures with ARG were prepared by spray drying in 1:1 and 1:2 molar ratios. The solid-state properties of the mixtures were characterized with X-ray powder diffraction (XRPD), Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) in stability studies under different storage conditions. Simultaneous dissolution/permeation studies were conducted in side-by-side diffusion cells with a PAMPA (parallel artificial membrane permeability assay) membrane as a permeation barrier. It was observed with XRPD that ARG, VER and PIP formed co-amorphous mixtures with FUR at both molar ratios. DSC and FTIR revealed single glass transition values for the mixtures (except for FUR:VER 1:2), with the formation of intermolecular interactions between the components, especially salt formation between FUR and ARG. The co-amorphous mixtures were found to be stable for at least two months under an elevated temperature/humidity, except FUR:ARG 1:2, which was sensitive to humidity. The dissolution/permeation studies showed that only the co-amorphous FUR:ARG mixtures were able to enhance both the dissolution and permeation of FUR. Thus, it is concluded that formulating co-amorphous salts with ARG may be a promising option for poorly soluble/permeable FUR.

Effects of Steam Heat and Dry Heat Sterilization on Thermal and Mechanical Properties of Nylon and Policarbonate in Fabrication with Fused Filament

2021 ◽  
Vol 891 ◽  
pp. 150-163
Author(s):  
Jorge Mauricio Fuentes ◽  
Omar Flor Unda ◽  
Santiago Ferrandiz ◽  
Franyelit Suarez
Keyword(s):  
Mechanical Properties ◽  
Thermomechanical Analysis ◽  
Mechanical Tests ◽  
Effect Of Temperature ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry ◽  
Thermal Tests ◽  
Dry Heat ◽  
Izod Impact ◽  
Steam Heat

In this article presents evidence about performance of mechanical properties of polycarbonate and nylon materials, which are used in the additive manufacturing by deposition of molten material and that have been subjected to sterilization processes by moist heat at 121°C and dry heat at 140°C. This study provides useful information to consider the use of these materials in sanitary and sterile settings. Mechanical tests of tensile, flex, hardness, Izod impact, thermal tests in Differential Scanning Calorimetry DSC, Thermomechanical analysis TMA and Scanning Electron Microscopy SEM were performed. It is concluded that the mechanical and thermal properties have not been altered through the effect of temperature in sterilization processes.

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