Bio-oil Phenol Formaldehyde Research Articles

Preparation of phenol-formaldehyde resin modified with phenol-rich pine needle pyrolysis oil and assessment of bonding strength

ABSTRACT The pine needles bio-oil was partially replaced with phenol-formaldehyde (PF) resin at a rate of up to 40% by weight. The wood adhesive characteristics of a newly produced bio-oil phenol-formaldehyde (BOPF) resin with 10% bio-oil replacements was found to be comparable to those of pure PF resin with similar shear strength. DSC revealed that the curing temperature of 20 wt-% BOPF resin decreased from 95 to 60°C. Thermal degradation of BOPF resins was somewhat lower than that of pure PF resin, according to TGA and DTG data, and was similar in 10 and 20 wt-% BOPF resins. The presence of methylene bridges between phenols shown by FTIR analysis indicated that the wood adhesive had a good quality. According to SEM examination, the 10 and 20% BOPF resins showed a flat microstructure comparable to the pure PF resin.

Aging Behaviors of Phenol-Formaldehyde Resin Modified by Bio-Oil under Five Aging Conditions.

The bio-oil phenol-formaldehyde (BPF) resin, prepared by using bio-oil as a substitute for phenol, has similar bonding strength but lower price to phenol-formaldehyde (PF) resin. As a common adhesive for outdoor wood, the aging performance of BPF resin is particularly important. The variations in mass, bonding strength, microstructure, atomic composition, and chemical structure of BPF resin under five aging conditions (heat treatment, water immersion, UV exposure, hydrothermal treatment, and weatherometer treatment) were characterized by scanning electron microscope, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy, respectively. Compared under five aging conditions, after aging 960 h, the mass loss of plywood and film was largest under hydrothermal treatment; the bonding strength of plywood, the surface roughness, and O/C ratio of the resin film changed most obviously under weatherometer treatment. FT-IR analysis showed that the decreased degree of peak intensity on CH2 and C–O–C characteristic peaks of BPF resin were weaker under water immersion, hydrothermal treatment, and weatherometer treatment than those of PF resin. The comparison of data between BPF and PF resins after aging 960 h showed that adding bio-oil could obviously weaken the aging effect of water but slightly enhance that of heat. The results could provide a basis for the aging resistance modification of BPF resin.

Formaldehyde and VOC emissions from plywood panels bonded with bio-oil phenolic resins

Pyrolysis bio-oil was used to partially substitute for phenol in reacting with formaldehyde for the production of bio-oil phenol formaldehyde plywood (BPFP) panels, with the phenol substitution ratio being 20%, 40%, or 60%. Emissions of formaldehyde and volatile organic compounds (VOCs) from the BPFP panels were studied using solid-phase micro-extraction (SPME) followed by headspace gas chromatography/mass spectrometry (GC/MS), and were compared to those from the phenol formaldehyde plywood (PFP) panels. The sources for VOCs were analyzed, and the health risks associated with the BPFP were examined. Results showed that at 80 °C: (1) Formaldehyde emissions from the BPFP panels were increased to about 4 times that of PFP; (2) VOCs emissions were significantly reduced by up to 84.9% mainly due to the greatly reduced phenol emissions, although the total number of VOCs was increased from 20 to 35; (3) BPFP presents greatly increased carcinogenic and non-carcinogenic health risks because of its much stronger emissions of formaldehyde, N,N-dimethylformamide, benzofuran, furfural, and many chemicals from the bio-oil. It is highly advisable that the health risks are properly taken care of before the wide application of BPFP, or similar bio-oil based engineered wood products.

Synthesis of Bio-Oilphenol-Formaldehyde Resins under Alkali Conditions

In the present study, bio-oil produced from vacuum pyrolysis of woody biomass has been investigated as a source of chemical feedstock. Bio-based resins were produced using the bio- oil with phenol substitutions ranging from 10 to 30 wt%. The conventional GC/MS analysis was carried out for the evaluation of the chemical composition of bio-oil. TGA, DSC and FT-IR analyses were used in order to characterize the bio-oil-phenol-formaldehyde (BPF) resins. The bonding quality of wood samples bonded with the BPF resins was investigated under different pre-treatment conditions. The highest shear strength was observed for the control samples bonded with the laboratory PF resin. As the amount of bio-oil was increased up to 30 wt%, the shear strength of the samples decreased from 12.08 to 11.76 N/mm2. The bonding performance was not negatively affected by the combination of bio-oil under dry conditions. According to TS EN 12765 standard, the relevant performance requirements for bonded samples under dry conditions must be at least 10 N/mm2. Relating to the standard, all samples bonded with BPF resins obtained the requirements for durability class C1. Under wet conditions, the bonding performance was negatively affected by the addition of bio-oil. However, the BPF resins fulfilled the durability requirements for C1, C2, and C3 specified in EN 12765 (2002).

Preparation of highly phenol substituted bio‐oil–phenol–formaldehyde adhesives with enhanced bonding performance using furfural as crosslinking agent

Highly phenol substituted bio‐oil–phenol–formaldehyde (BPF) adhesives were prepared via the phenolization‐copolymerization method, in which furfural was used as a novel crosslinking agent to improve the bonding performance. The effects of bio‐oil percentage, furfural content, curing temperature, and pressure on the performance of BPF adhesives have been studied in detail. A BPF adhesive with 75% bio‐oil percentage and 15% furfural loading (named 75BPF_15) was synthesized, which was cured at 180 °C and 4 MPa. Compared to the conventional phenol–formaldehyde adhesive, the wet tensile strength of 75BPF_15 adhesive reached 2.84 MPa, which was significantly higher than the 1.54 MPa of PF. A possible mechanism of BPF adhesives crosslinked with furfural is proposed. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 46995.

Formaldehyde emission behavior of plywood with phenol-formaldehyde resin modified by bio-oil under radiant floor heating condition

Bio-oil was added as a substitute of phenol for phenol-formaldehyde (PF) resin to reduce the cost and formaldehyde emission (FE) in radiant floor heating system. The effects of substitute rate of bio-oil to phenol, temperature and heating time of radiant floor heating system on the FE of plywood with bio-oil phenol-formaldehyde (BPF) resin were examined using desiccator method. The variations on chemical structure of cured BPF resin were analyzed by the Fourier transform infrared spectroscopy (FT-IR) and solid-state nuclear magnetic resonance (NMR) to understand the FE behavior of plywood. Results showed that the FE of plywood was increased at prolonged heating time and the temperature significantly affected FE of plywood; the initial FE value at 50 °C was 20–30 times as higher as that at 20 °C. Elevated temperature increased the final equilibrium FE value and shortened the time to reach the balance. However, adding bio-oil reduced the initial and final equilibrium FE values, decreasing by 12–49% and 25–51%, respectively. Analytical results revealed that the initial FE was mainly from the residual formaldehyde from the manufacturing of plywood and the subsequent FE released owing to the breakage of C–O–C and CH2 bonds in resin.

Synthesis of biobased phenolic resins using catalytic pyrolysis oil and its effect on oriented strand board performance

ABSTRACTThe aim of this work is to investigate the chemical, physical, thermal and mechanical properties of bio-oil-phenol–formaldehyde (BPF) resin synthesized with catalytic pyrolysis oil. In this way, catalysed and uncatalysed pyrolysis processes were carried out in a vacuum pyrolysis reactor at the temperature of 500°C. Sodium hydroxide (NaOH) and potassium hydroxide (KOH) were used as catalysts in the catalysed pyrolysis processes. The BPF resins were synthesized using the bio-oil at 10 wt%, 20 wt%, 30 wt%, 40 wt% and 50 wt% phenol replacement levels. The chemical composition of the bio-oil was analyzed by GC/MS analysis. The thermal characteristics and chemical structures of the resins were characterized by TGA and FT-IR analysis, respectively. Physical properties including pH, viscosity, solid content and gel time of the resins were determined. Oriented Strand Board (OSB) were manufactured to evaluate the mechanical performances of modified resins. The BPF resins were successfully synthesized with phenol, bio-oil and formaldehyde. BPF resins synthesized with catalytic bio-oils showed better thermal stability than BPF resin synthesized with non-catalytic bio-oil. The mechanical test results showed that the IB strengths of OSBs made with BPF resins synthesized by use of NaOH exhibited better performance than OSBs commercial PF made.

Investigation of aging performance of bio‐oil phenol‐formaldehyde resin with the treatment of artificial accelerated aging method

The aging performance of bio‐oil phenol‐formaldehyde (BPF) resin was investigated using artificial accelerated aging method. After the treatment, the variations on the mass and bonding strength of plywood with BPF resin were determined. The changes in the microstructure, functional groups, and chemical bonds of adhesive films with BPF resin were also analyzed by scanning electron microscope, Fourier transform infrared spectroscopy, and X‐ray photoelectron spectroscopy analysis. The decrease of mass loss and bonding strength of BPF resin were smaller, the surface of BPF resin was smoother, and the amounts of CH2 groups and COC groups of BPF resin were larger than that of phenol‐formaldehyde (PF) resin at the same aged period. These results indicated that the bio‐oil could be used to improve the aging performance of PF resin. POLYM. ENG. SCI., 58:1810–1816, 2018. © 2017 Society of Plastics Engineers

Activated carbon monolith derived from polymer and fast pyrolytic char: Effect of bio-oil phenol-formaldehyde resin

Activated carbon monoliths (ACMs) were fabricated by H2O activation using powdered fast pyrolytic char (PFPC) as a raw material and bio-oil phenol-formaldehyde (BPF) resin as a binder. The effects of the ratio of BPF resin to PFPC on textural and chemical-surface properties of the ACMs were investigated using elemental analysis, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and field-emission scanning electron microscopy (FE-SEM). The adsorption capacity and mechanical properties under different conditions were examined by N2 adsorption analysis and compression strength, respectively. The results indicated that the optimal ratio was 20 wt.% BPF resin binder. The compression strength of ACMs with a carbon content of 79.7 wt.% reached 3.74 MPa, while the BET surface area and total pore volume were 731.3 m2/g and 0.589 cm3/g, respectively. ACMs appeared to be mainly mesoporous with low graphitization and contained multiple functional groups such as alkyl, esters, ether, phenol, olefin, etc.

Synthesis and Characterization of Bio-Oil Phenol Formaldehyde Resin Used to Fabricate Phenolic Based Materials.

In this study, bio-oil from the fast pyrolysis of renewable biomass was used as the raw material to synthesize bio-oil phenol formaldehyde (BPF) resin—a desirable resin for fabricating phenolic-based material. During the synthesis process, paraformaldehyde was used to achieve the requirement of high solid content and low viscosity. The properties of BPF resins were tested. Results indicated that BPF resin with the bio-oil addition of 20% had good performance on oxygen index and bending strength, indicating that adding bio-oil could modify the fire resistance and brittleness of PF resin. The thermal curing behavior and heat resistance of BPF resins were investigated by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Results showed that adding bio-oil had an impact on curing characteristics and thermal degradation process of PF resin, but the influence was insignificant when the addition was relatively low. The chemical structure and surface characteristics of BPF resins were determined by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The analysis demonstrated that adding bio-oil in the amount of 20% was able to improve the crosslinking degree and form more hydrocarbon chains in PF resin.

Fabrication of Glass Fiber Reinforced Composites Based on Bio-Oil Phenol Formaldehyde Resin.

In this study, bio-oil from fast pyrolysis of renewable biomass was added by the mass of phenol to synthesize bio-oil phenol formaldehyde (BPF) resins, which were used to fabricate glass fiber (GF) reinforced BPF resin (GF/BPF) composites. The properties of the BPF resin and the GF/BPF composites prepared were tested. The functional groups and thermal property of BPF resin were thoroughly investigated by Fourier transform infrared (FTIR) spectra and dynamic thermomechanical analysis (DMA). Results indicated that the addition of 20% bio-oil exhibited favorable adaptability for enhancing the stiffness and heat resistance of phenol formaldehyde (PF) resin. Besides, high-performance GF/BPF composites could be successfully prepared with the BPF resin based on hand lay-up process. The interface characteristics of GF/BPF composites were determined by the analysis of dynamic wettability (DW) and scanning electron microscopy (SEM). It exhibited that GF could be well wetted and embedded in the BPF resin with the bio-oil addition of 20%.

Preparation of Activated Carbon Using Bio-Oil Phenol-Formaldehyde Resin

High-specific surface area activated carbon with distinct pore texture was prepared using bio-oil phenol-formaldehyde (BPF) resin as the raw material and KOH as the activator for chemical activation. The carbonization process was characterized with thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR).The pore texture was characterized with measurements obtained by N2 adsorption analysis and scanning electron microscopy (SEM). It was found that adding bio-oil to phenol-formaldehyde resin can partly enhance the thermal stability and improve the textural properties of activated carbon. The functional groups of BPF resin gradually disappeared in the carbonization reaction with increasing temperature. The activated carbon prepared by BPF resin with 30%wt bio-oil exhibited the optimal perfomance.

Cure Kinetics, Bonding Performance, Thermal Degradation, and Biocidal Studies of Phenol-Formaldehyde Resins Modified with Crude Bio-oil Prepared from Ziziphus mauritiana Endocarps

Crude bio-oil, extracted from endocarp bio-waste of Ziziphus mauritiana by direct liquefaction (ethanol-water 1:1 w/w; 300 °C), was used to replace petro-phenol (30% to 75% w/w) in the development of bio-oil-phenol formaldehyde (BPF) resol resins. Cure kinetics of the BPF resins were studied by the DSC method, while the thermal degradation was studied by the TGA method. Bonding performance of the BPF resins was measured by single lap-shear method, while biocidal properties were investigated by antifungal index (%) and termite mortality (%) test. The DSC studies revealed that beyond 45% bio-oil incorporation (BOI), the curing process of the BPF resins got deferred. The TGA studies showed that BOI decreased the thermal stability of the BPF resins by lowering the decomposition temperatures and the char residue. The measured values of antifungal index (%) and termite mortality (%) revealed that incorporation of bio-oil enhanced the fungal and termite resistance of the resins. From data of thermal cure, bonding strength, thermal stability, and biocidal properties of the BPF resins it appears that petro-phenol could be substituted by up to 45% w/w of crude bio-oil safely in the development of bio-oil-phenol formaldehyde resol resins.

Characterization of Phenol-Formaldehyde Resins Modified with Crude Bio-oil Prepared from Ziziphus mauritiana Endocarps

This study was conducted to evaluate the effects of bio-oil incorporation on properties of bio-oil-phenol formaldehyde (BPF) resol resins along with the optimization of petro-phenol substitution level. Crude bio-oil prepared from endocarp shells of Ziziphus mauritiana by direct solvolytic liquefaction (ethanol-water 1:1 wt./wt. at 300 °C) was used to partially substitute the petro-phenol (30% to 75% wt./wt.) in the resin synthesis. The modified resins were subjected to measurement of various properties, including molecular weight, pH, viscosity, density, gel/cure time, non-volatile solid content, and limiting oxygen index. Bonding performance of the BPF resins was evaluated by measuring the mechanical and hygroscopic properties of the particle boards developed using such resins. With the incorporation of bio-oil, the viscosity and molecular weight of the BPF resins increased, while the values of pH, density, non-volatile solid content, and limiting oxygen index decreased. The gel, cure, and bonding tests revealed that with the addition of more than 45% bio-oil, the gel/cure times of the BPF resins increased, while the bonding performance decreased. Petro-phenol could therefore be substituted by crude bio-oil up to 45% wt./wt. safely.

Preparation of Bio-Oil-Phenol-Formaldehyde Resins from Biomass Pyrolysis Oil

Three kinds of bio-oil-phenol-formaldehyde (BPF) resins were prepared which contained 30 wt% replacement of phenol with bio-oil derived from poplar, larch and bamboo. Main component of different pyrolysis bio-oil, physical properties of different BPF resins and their plywood specimens were investigated. The results show that phenolics in bio-oil derived from poplar, larch and bamboo are 13.8653%, 14.7529% and 10.3987%. All the experimental BPF resins have similar physical properties, which comply with GB/T 14732-2006. The performance of the plywood specimens bonded with different BPF resins were larch-BPF > poplar-BPF > bamboo-BPF, all of which could achieve the demands of GB/T 9846-2004.

Use of biocrude derived from woody biomass to substitute phenol at a high‐substitution level for the production of biobased phenolic resol resins

AbstractPhenolic bio‐oil produced by the direct liquefaction of Eastern white pine (Pinus Strobus L.) sawdust in a hot‐compressed ethanol‐water (1:1 w/w) medium at 300 °C was used to partially substitute for phenol in the synthesis of bio‐oil‐phenol‐formaldehyde (BPF) resol resins. Bio‐based resol resins with high levels of phenol substitution (up to 75 wt%) could be used as plywood adhesives because of the low molecular weights found for the phenolic bio‐oil (weight‐average molecular weight = 1072 g/mol, number‐average molecular weight = 342 g/mol). The properties of the BPF resol resins were analyzed by differential scanning calorimetry, Fourier transform infrared spectroscopy, gel permeation chromatography, and thermogravimetric analysis. All of the experimental BPF resins possessed broad molecular weight distributions but had similar chemical/thermal properties compared to a conventional phenol–formaldehyde (PF) resol resin reference (or 0 wt % BPF resin). The BPFs exhibited the typical properties of a thermosetting PF resin, for example, an exothermic curing temperature of 140–150°C and an acceptable residual carbon yield of 48–72 wt % nonvolatile content at 700°C. The experimental BPFs were applied as adhesives in the assembly of plywood, and then, the dry/wet tensile strengths were evaluated. The tensile strengths of the dry plywood samples bonded with the BPF resins up to a high ratio value of 75 wt % bio‐oil exceeded or were comparable to that of the conventional pure PF resin adhesive. All of the BPF‐resin‐bonded plywood samples gave wet tensile strengths comparable to those of the conventional PF adhesive. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011