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Valchev I, Savov V, Yordanov I, Petrin S, Antov P. Effect of Hot-Pressing Temperature on the Properties of Eco-Friendly Fiberboard Panels Bonded with Hydrolysis Lignin and Phenol-Formaldehyde Resin. Polymers (Basel) 2024; 16:1059. [PMID: 38674979 PMCID: PMC11054965 DOI: 10.3390/polym16081059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 04/05/2024] [Accepted: 04/07/2024] [Indexed: 04/28/2024] Open
Abstract
Lignin is the natural binder in wood and lignocellulosic plants and is regarded as the main natural and renewable source of phenolic compounds. Its incorporation in the composition of fiberboards will enhance both the environmental performance of the panels and the complex use of natural resources. In recent years, the increased valorization of hydrolysis lignin in value-added applications, including adhesives for bonding fiberboard panels, has gained significant research interest. Markedly, a major drawback is the retention of lignin in the pulp until the hot-pressing process. This problem could be overcome by using a small content of phenol-formaldehyde (PF) resin in the adhesive mixture as an auxiliary binder. The aim of this research work was to investigate and evaluate the effect of the hot-pressing temperature, varied from 150 °C to 200 °C, in a modified hot-press cycle on the main physical and mechanical properties of fiberboard panels bonded with unmodified technical hydrolysis lignin (THL) as the main binder and PF resin as an auxiliary one. It was found that panels with very good mechanical properties can be fabricated even at a hot-pressing temperature of 160 °C, while to provide the panels with satisfactory waterproof properties, it is necessary to have a hot-pressing temperature of at least 190 °C.
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Affiliation(s)
- Ivo Valchev
- Faculty of Chemical Technologies, University of Chemical Technology and Metallurgy, 1757 Sofia, Bulgaria; (I.V.); (I.Y.); (S.P.)
| | - Viktor Savov
- Faculty of Forest Industry, University of Forestry, 1797 Sofia, Bulgaria;
| | - Ivaylo Yordanov
- Faculty of Chemical Technologies, University of Chemical Technology and Metallurgy, 1757 Sofia, Bulgaria; (I.V.); (I.Y.); (S.P.)
| | - Stoyko Petrin
- Faculty of Chemical Technologies, University of Chemical Technology and Metallurgy, 1757 Sofia, Bulgaria; (I.V.); (I.Y.); (S.P.)
| | - Petar Antov
- Faculty of Forest Industry, University of Forestry, 1797 Sofia, Bulgaria;
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Sarika PR, Nancarrow P, Makkawi Y, Ibrahim TH. Preparation and Characterization of Date Palm Bio-Oil Modified Phenolic Foam. Polymers (Basel) 2024; 16:955. [PMID: 38611213 PMCID: PMC11013855 DOI: 10.3390/polym16070955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 03/26/2024] [Accepted: 03/27/2024] [Indexed: 04/14/2024] Open
Abstract
In this work, the potential of biomass-derived date palm bio-oil as a partial substitute for phenol in the phenolic resin was evaluated. Date palm bio-oils derived from date palm were used for the partial substitution of phenol in the preparation of phenolic foam (PF) insulation materials. Date palm waste material was processed using pyrolysis at 525 °C to produce bio-oil rich in phenolic compounds. The bio-oil was used to partially replace phenol in the synthesis of phenolic resin, which was subsequently used to prepare foams. The resulting changes in the physical, mechanical, and thermal properties of the foams were studied. The substituted foams exhibited 93%, 181%, and 40% improvement in compressive strength with 10%, 15%, and 20% bio-oil substitution, respectively. Due to the incorporation of biomass waste material, the partial reduction in phenol uses, and the favorable properties, the date palm bio-oil substituted phenolic foams are considered more environmentally benign alternatives to traditional phenolic foams.
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Affiliation(s)
| | - Paul Nancarrow
- Department of Chemical and Biological Engineering, American University of Sharjah, Sharjah P.O. Box 26666, United Arab Emirates; (P.R.S.); (Y.M.); (T.H.I.)
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Aleksandrov L, Rangelova N, Lazarova-Zdravkova N, Georgieva N, Dragnevska M, Nenkova S. Preparation, Characterization, and Antibacterial Properties of Cu-Fibreboards. MATERIALS (BASEL, SWITZERLAND) 2023; 16:6936. [PMID: 37959533 PMCID: PMC10650183 DOI: 10.3390/ma16216936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 10/12/2023] [Accepted: 10/27/2023] [Indexed: 11/15/2023]
Abstract
In the present study, copper modified fibreboards were prepared and their existing phase, morphology, and antibacterial behaviour were investigated. The copper content and the physical and mechanical properties of fibreboards (thickness, bending strength, and swelling) were determined. X-ray diffraction analysis (XRD) showing diffraction peaks typical for cellulose, Cu2S, and Na2SO4, depended on the preparation conditions. The average size of the Cu2S crystals varied between 20 and 50 nm. The morphology of the obtained fibreboards, as well as the size and shape of copper particles, were observed by scanning electron microscopy (SEM) and transition electron microscopy (TEM). The antibacterial activity was tested against Gram-positive (Bacillus subtilis 3562) and Gram-negative (Escherichia coli K12 407) bacteria. The tests showed that the materials had higher antibacterial activity against E. coli, which depended on their preparation conditions. Based on these results, the obtained copper fibreboards can be used as antibacterial agents in the packaging and building industry.
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Affiliation(s)
- Lyubomir Aleksandrov
- Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
| | - Nadezhda Rangelova
- Department of Industrial Safety, University of Chemical Technology and Metallurgy, 1756 Sofia, Bulgaria;
| | - Nevena Lazarova-Zdravkova
- Department of Biotechnology, University of Chemical Technology and Metallurgy, 1756 Sofia, Bulgaria; (N.L.-Z.); (N.G.)
| | - Nelly Georgieva
- Department of Biotechnology, University of Chemical Technology and Metallurgy, 1756 Sofia, Bulgaria; (N.L.-Z.); (N.G.)
| | - Mirela Dragnevska
- Department of Pulp, Paper and Printing Arts, University of Chemical Technology and Metallurgy, 1756 Sofia, Bulgaria; (M.D.); (S.N.)
| | - Sanchi Nenkova
- Department of Pulp, Paper and Printing Arts, University of Chemical Technology and Metallurgy, 1756 Sofia, Bulgaria; (M.D.); (S.N.)
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Green Phenolic Resins from Oil Palm Empty Fruit Bunch (EFB) Phenolated Lignin and Bio-Oil as Phenol Substitutes for Bonding Plywood. Polymers (Basel) 2023; 15:polym15051258. [PMID: 36904501 PMCID: PMC10007611 DOI: 10.3390/polym15051258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 02/22/2023] [Accepted: 02/27/2023] [Indexed: 03/06/2023] Open
Abstract
Lignin is a natural biopolymer with a complex three-dimensional network and it is rich in phenol, making it a good candidate for the production of bio-based polyphenol material. This study attempts to characterize the properties of green phenol-formaldehyde (PF) resins produced through phenol substitution by the phenolated lignin (PL) and bio-oil (BO), extracted from oil palm empty fruit bunch black liquor. Mixtures of PF with varied substitution rates of PL and BO were prepared by heating a mixture of phenol-phenol substitute with 30 wt.% NaOH and 80% formaldehyde solution at 94 °C for 15 min. After that, the temperature was reduced to 80 °C before the remaining 20% formaldehyde solution was added. The reaction was carried out by heating the mixture to 94 °C once more, holding it for 25 min, and then rapidly lowering the temperature to 60 °C, to produce the PL-PF or BO-PF resins. The modified resins were then tested for pH, viscosity, solid content, FTIR, and TGA. Results revealed that the substitution of 5% PL into PF resins is enough to improve its physical properties. The PL-PF resin production process was also deemed environmentally beneficial, as it met 7 of the 8 Green Chemistry Principle evaluation criteria.
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Savov V, Antov P, Zhou Y, Bekhta P. Eco-Friendly Wood Composites: Design, Characterization and Applications. Polymers (Basel) 2023; 15:polym15040892. [PMID: 36850175 PMCID: PMC9966963 DOI: 10.3390/polym15040892] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 02/08/2023] [Indexed: 02/15/2023] Open
Abstract
The ongoing transition from a linear to a circular, low-carbon bioeconomy is crucial for reducing the consumption of global natural resources, minimizing waste generation, reducing carbon emissions, and creating more sustainable growth and jobs, the prerequisites necessary to achieve climate neutrality targets and stop biodiversity loss [...].
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Affiliation(s)
- Viktor Savov
- Faculty of Forest Industry, University of Forestry, 1797 Sofia, Bulgaria
- Correspondence: (V.S.); (P.A.)
| | - Petar Antov
- Faculty of Forest Industry, University of Forestry, 1797 Sofia, Bulgaria
- Correspondence: (V.S.); (P.A.)
| | - Yonghui Zhou
- Department of Civil and Environmental Engineering, Brunel University London, Uxbridge UB8 3PH, UK
| | - Pavlo Bekhta
- Department of Wood-Based Composites, Cellulose and Paper, Ukrainian National Forestry University, 79057 Lviv, Ukraine
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Reh R, Kristak L, Antov P. Advanced Eco-Friendly Wood-Based Composites. MATERIALS (BASEL, SWITZERLAND) 2022; 15:8651. [PMID: 36500147 PMCID: PMC9739782 DOI: 10.3390/ma15238651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 11/18/2022] [Indexed: 06/17/2023]
Abstract
In collaboration with the MDPI publishing house, we are pleased to introduce the reader to our new project, the Special Issue entitled "Advanced Eco-friendly Wood-Based Composites" [...].
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Affiliation(s)
- Roman Reh
- Faculty of Wood Sciences and Technology, Technical University in Zvolen, 960 01 Zvolen, Slovakia
| | - Lubos Kristak
- Faculty of Wood Sciences and Technology, Technical University in Zvolen, 960 01 Zvolen, Slovakia
| | - Petar Antov
- Faculty of Forest Industry, University of Forestry, 1797 Sofia, Bulgaria
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Dorieh A, Ayrilmis N, Farajollah Pour M, Ghafari Movahed S, Valizadeh Kiamahalleh M, Shahavi MH, Hatefnia H, Mehdinia M. Phenol formaldehyde resin modified by cellulose and lignin nanomaterials: Review and recent progress. Int J Biol Macromol 2022; 222:1888-1907. [DOI: 10.1016/j.ijbiomac.2022.09.279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 09/06/2022] [Accepted: 09/28/2022] [Indexed: 11/05/2022]
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Influence of Lignin Content and Pressing Time on Plywood Properties Bonded with Cold-Setting Adhesive Based on Poly (Vinyl Alcohol), Lignin, and Hexamine. Polymers (Basel) 2022; 14:polym14102111. [PMID: 35631993 PMCID: PMC9144503 DOI: 10.3390/polym14102111] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 05/15/2022] [Accepted: 05/20/2022] [Indexed: 12/18/2022] Open
Abstract
The sustainability, performance, and cost of production in the plywood industry depend on wood adhesives and the hot-pressing process. In this study, a cold-setting plywood adhesive was developed based on polyvinyl alcohol (PVOH), high-purity lignin, and hexamine. The influence of lignin content (10%, 15%, and 20%) and cold-pressing time (3, 6, 12, and 24 h) on cohesion, adhesion, and formaldehyde emission of plywood were investigated through physical, chemical, thermal, and mechanical analyses. The increased lignin addition level lowered the solids content, which resulted in reduced average viscosity of the adhesive. As a result, the cohesion strength of the adhesive formulation with 10% lignin addition was greater than those of 15% and 20% lignin content. Markedly, the adhesive formulation containing a 15% lignin addition level exhibited superior thermo-mechanical properties than the blends with 10% and 20% lignin content. This study showed that 10% and 15% lignin content in the adhesive resulted in better cohesion strength than that with 20% lignin content. However, statistical analysis revealed that the addition of 20% lignin in the adhesive and using a cold-pressing time of 24 h could produce plywood that was comparable to the control polyurethane resins, i.e., dry tensile shear strength (TSS) value of 0.95 MPa, modulus of rupture (MOR) ranging from 35.8 MPa, modulus of elasticity (MOE) values varying from 3980 MPa, and close-to-zero formaldehyde emission (FE) of 0.1 mg/L, which meets the strictest emission standards. This study demonstrated the feasibility of fabricating eco-friendly plywood bonded with PVOH–lignin–hexamine-based adhesive using cold pressing as an alternative to conventional plywood.
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