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Kawalerczyk J, Walkiewicz J, Sedliačik J, Dukarska D, Woźniak M, Mirski R. Modified Buckwheat Husk as a Filler for Urea-Formaldehyde Resin in Plywood Production. Polymers (Basel) 2024; 16:1350. [PMID: 38794543 PMCID: PMC11124799 DOI: 10.3390/polym16101350] [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: 04/24/2024] [Revised: 05/06/2024] [Accepted: 05/07/2024] [Indexed: 05/26/2024] Open
Abstract
The aim of the presented research was to determine the suitability of both non-modified and modified buckwheat husk (BH) as a filler for urea-formaldehyde adhesive in plywood production. The effect of two modification methods, acetylation and silanization, was investigated. Infrared spectroscopy outcomes confirmed that both acetylation and silanization of the filler had occurred. Based on the results, it was found that the introduction of BH had a significant effect on both the adhesive properties and the characteristics of the manufactured plywood. The application of non-modified husks led to a reduction in viscosity and an extension of the gelation time, and the produced plywood boards were characterized by reduced bonding quality and increased delamination. Modification of the husk surface by acetylation and silanization with 3-aminopropyltriethoxysilane contributed to the noticeable improvement in the resin properties. On the other hand, the improvement in plywood properties, consisting of the increase in bonding quality and reduced delamination, was observed only in the case of the silanized husk. Furthermore, the use of non-modified and acetylated husk did not significantly influence the formaldehyde emission. The reduction in the investigated emission of formaldehyde was observed only in the case of variants containing 15 and 20% of silanized buckwheat husk.
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Affiliation(s)
- Jakub Kawalerczyk
- Department of Mechanical Wood Technology, Faculty of Forestry and Wood Technology, Poznań University of Life Sciences, 60-627 Poznań, Poland; (J.W.); (D.D.); (R.M.)
| | - Joanna Walkiewicz
- Department of Mechanical Wood Technology, Faculty of Forestry and Wood Technology, Poznań University of Life Sciences, 60-627 Poznań, Poland; (J.W.); (D.D.); (R.M.)
| | - Ján Sedliačik
- Department of Furniture and Wood Products, Faculty of Wood Science and Technology, Technical University in Zvolen, 96053 Zvolen, Slovakia;
| | - Dorota Dukarska
- Department of Mechanical Wood Technology, Faculty of Forestry and Wood Technology, Poznań University of Life Sciences, 60-627 Poznań, Poland; (J.W.); (D.D.); (R.M.)
| | - Magdalena Woźniak
- Department of Chemistry, Faculty of Forestry and Wood Technology, Poznań University of Life Sciences, 60-627 Poznań, Poland;
| | - Radosław Mirski
- Department of Mechanical Wood Technology, Faculty of Forestry and Wood Technology, Poznań University of Life Sciences, 60-627 Poznań, Poland; (J.W.); (D.D.); (R.M.)
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2
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Bartoszuk K, Kowaluk G. The Influence of the Content of Recycled Natural Leather Residue Particles on the Properties of High-Density Fiberboards. MATERIALS (BASEL, SWITZERLAND) 2023; 16:5340. [PMID: 37570042 PMCID: PMC10419617 DOI: 10.3390/ma16155340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/23/2023] [Accepted: 07/27/2023] [Indexed: 08/13/2023]
Abstract
During the production of furniture, large amounts of waste materials are generated, which are most often stored in warehouses without a specific purpose for their subsequent use. In highly developed countries, as many as 25 million tons of textile waste are produced annually, of which approximately 40% is non-clothing waste such as carpets, furniture and car upholstery. The aim of this research was to produce and evaluate dry-formed high-density fiberboards (HDF) bonded with urea-formaldehyde resin, 12% resination, with various shares of recycled particles of natural leather used in upholstery furniture production at different contents (1, 5 and 10% by weight). The panels were hot-pressed (200 °C, 2.5 MPa, pressing factor 20 s mm-1). Mechanical properties (modulus of rupture, modulus of elasticity and screw withdrawal resistance) and physical properties (density profile, thickness swelling after water immersion, water absorption and surface absorption) were tested. The density profile and contact angle of natural leather have been also characterized. The results show that increasing the content of leather particles in HDF mostly has a positive effect on mechanical properties, especially screw withdrawal resistance and water absorption. It can be concluded that, depending on the further use of HDF, it is possible to use recovered upholstery leather particles as a reasonable addition to wood fibers in HDF technology.
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Affiliation(s)
- Katarzyna Bartoszuk
- Faculty of Wood Technology, Warsaw University of Life Sciences—SGGW, Nowoursynowska St. 159, 02-787 Warsaw, Poland;
| | - Grzegorz Kowaluk
- Institute of Wood Science and Furniture, Warsaw University of Life Sciences—SGGW, Nowoursynowska St. 159, 02-776 Warsaw, Poland
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3
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Vitrone F, Brinker S, Ramos D, Ferrando F, Salvadó J, Mai C. Approaching Self-Bonded Medium Density Fiberboards Made by Mixing Steam Exploded Arundo donax L. and Wood Fibers: A Comparison with pMDI-Bonded Fiberboards on the Primary Properties of the Boards. MATERIALS (BASEL, SWITZERLAND) 2023; 16:4343. [PMID: 37374527 DOI: 10.3390/ma16124343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 05/30/2023] [Accepted: 06/08/2023] [Indexed: 06/29/2023]
Abstract
This study presents an unexplored method to produce formaldehyde-free MDF. Steam exploded Arundo donax L. (STEX-AD) and untreated wood fibers (WF) were mixed at different mixing rates (0/100, 50/50, and 100/0, respectively) and two series of boards were manufactured, with 4 wt% of pMDI, based on dry fibers, and self-bonded. The mechanical and physical performance of the boards was analyzed as a function of the adhesive content and the density. The mechanical performance and dimensional stability were determined by following European standards. The material formulation and the density of the boards had a significant effect on both mechanical and physical properties. The boards made solely of STEX-AD were comparable to those made with pMDI, while the panels made of WF without adhesive were those that performed the worst. The STEX-AD showed the ability to reduce the TS for both pMDI-bonded and self-bonded boards, although leading to a high WA and a higher short-term absorption for the latter. The results presented show the feasibility of using STEX-AD in the manufacturing of self-bonded MDF and the improvement of dimensional stability. Nonetheless, further studies are needed especially to address the enhancement of the internal bond (IB).
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Affiliation(s)
- Federica Vitrone
- Department of Chemical Engineering, Rovira I Virgili University, Avinguda dels Països Catalans, 26, 43007 Tarragona, Spain
| | - Sascha Brinker
- Department of Wood Biology and Wood Products, Georg-August-University of Göttingen, Büsgenweg 4, 37077 Gottingen, Germany
| | - Diego Ramos
- Department of Mechanical Engineering, Rovira I Virgili University, Avinguda dels Països Catalans, 26, 43007 Tarragona, Spain
| | - Francesc Ferrando
- Department of Mechanical Engineering, Rovira I Virgili University, Avinguda dels Països Catalans, 26, 43007 Tarragona, Spain
| | - Joan Salvadó
- Department of Chemical Engineering, Rovira I Virgili University, Avinguda dels Països Catalans, 26, 43007 Tarragona, Spain
| | - Carsten Mai
- Department of Wood Biology and Wood Products, Georg-August-University of Göttingen, Büsgenweg 4, 37077 Gottingen, Germany
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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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Ma Y, Luo Y, Zhang Q, Gao Y, Li J, Shah S, Wang X, Zhang X. Biodegradable Films Prepared from Pulp Lignocellulose Adhesives of Urea Formaldehyde Resin Modified by Biosulfonate. Polymers (Basel) 2022; 14:2863. [PMID: 35890638 PMCID: PMC9319740 DOI: 10.3390/polym14142863] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/10/2022] [Accepted: 07/11/2022] [Indexed: 12/04/2022] Open
Abstract
Traditional low-density polyethylene (LDPE) film causes environmental pollution; there is a pressing need to make new bio-based polymers for alternative products, to meet agricultural production needs and for sustainable ecological development. In this study, urea-formaldehyde resin (UF) was modified with polyvinyl alcohol (PVA) and 1-2.5% bio-based sulfonate (BBS). The influence of BBS inducing on the functional groups, microstructure, and thermal behavior was evaluated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). A biodegradable film was prepared with modified UF resin as adhesive and pulp lignocellulose as raw material. The biodegradable mulch film samples were tested for biodegradability, water retention, and cooling soil temperature characters using LDPE and no mulching (NM) as a control. The results showed that with the increase of BBS content, the viscosity and reactivity of modified PUF resin increased, and the free formaldehyde content decreased. A 2%BBS modified PUF resin (2.0BBS/PUF) accelerated the curing process of the PUF resin, formed a flexible macromolecular network structure, and enhanced the toughness of the resin. The biodegradable mulch prepared with PUF, BBS, and 2.0BBS/PUF as adhesives had good water retention. BBS modification increased the degradation rate of mulch by 17.53% compared to the PUF. Three biodegradable films compared with LDPE and NM significantly reduced the soil temperature under summer cucumber cultivation, and the 2.0BBS/PUF coating had the lowest diurnal temperature difference, which provided a suitable soil environment for crop growth.
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Affiliation(s)
- Yongjie Ma
- School of Agriculture, Ningxia University, Yinchuan 750021, China; (Y.M.); (Y.L.); (Q.Z.); (Y.G.); (J.L.)
| | - Yanxin Luo
- School of Agriculture, Ningxia University, Yinchuan 750021, China; (Y.M.); (Y.L.); (Q.Z.); (Y.G.); (J.L.)
| | - Qiannan Zhang
- School of Agriculture, Ningxia University, Yinchuan 750021, China; (Y.M.); (Y.L.); (Q.Z.); (Y.G.); (J.L.)
| | - Yanming Gao
- School of Agriculture, Ningxia University, Yinchuan 750021, China; (Y.M.); (Y.L.); (Q.Z.); (Y.G.); (J.L.)
| | - Jianshe Li
- School of Agriculture, Ningxia University, Yinchuan 750021, China; (Y.M.); (Y.L.); (Q.Z.); (Y.G.); (J.L.)
| | - Sadiq Shah
- Abdul Wali Khan Univ Dept Food Sci & Technol, Garden Campus, Mardan 23200, Pakistan;
| | - Xiaozhuo Wang
- School of Agriculture, Ningxia University, Yinchuan 750021, China; (Y.M.); (Y.L.); (Q.Z.); (Y.G.); (J.L.)
| | - Xueyan Zhang
- School of Agriculture, Ningxia University, Yinchuan 750021, China; (Y.M.); (Y.L.); (Q.Z.); (Y.G.); (J.L.)
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Three Adhesive Recipes Based on Magnesium Lignosulfonate, Used to Manufacture Particleboards with Low Formaldehyde Emissions and Good Mechanical Properties. FORESTS 2022. [DOI: 10.3390/f13050737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Adhesives represent an important part in the wood-based composite production, and taking into account their impact on the environment and human health, it is a challenge to find suitable natural adhesives. Starting from the current concerns of finding bio-adhesives, this paper aims to use magnesium lignosulfonate in three adhesive recipes for particleboard manufacturing. First, the adhesive recipes were established, using oxygenated water to oxidize magnesium lignosulfonate (Recipe 1) and adding 3% polymeric diphenylmethane diisocyanate (pMDI) crosslinker (Recipe 2) and a mixture of 2% polymeric diphenylmethane diisocyanate with 15% glucose (Recipe 3). The particleboard manufacturing technology included operations for sorting particles and adhesive recipes, pressing the mats, and testing the mechanical strengths and formaldehyde emissions. The standardized testing methodology for formaldehyde emissions used in the research was the method of gas analysis. Tests to determine the resistance to static bending and internal cohesion for all types of boards and recipes were also conducted. The average values of static bending strengths of 0.1 N/mm2, 0.38 N/mm2, and 0.41 N/mm2 were obtained for the particleboard manufacturing with the three adhesive recipes and were compared with the minimal value of 0.35 N/mm2 required by the European standard in the field. Measuring the formaldehyde emissions, it was found that the three manufacturing recipes fell into emission classes E1 and E0. Recipes 2 and 3 were associated with good mechanical performances of particleboards, situated in the required limits of the European standards. As a main conclusion of the paper, it can be stated that the particleboards made with magnesium-lignosulphonate-based adhesive, with or without crosslinkers, can provide low formaldehyde emissions and also good mechanical strengths when crosslinkers such as pMDI and glucose are added. In this way magnesium lignosulfonate is really proving to be a good bio-adhesive.
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Savov V, Valchev I, Antov P, Yordanov I, Popski Z. Effect of the Adhesive System on the Properties of Fiberboard Panels Bonded with Hydrolysis Lignin and Phenol-Formaldehyde Resin. Polymers (Basel) 2022; 14:polym14091768. [PMID: 35566951 PMCID: PMC9105454 DOI: 10.3390/polym14091768] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Revised: 04/11/2022] [Accepted: 04/25/2022] [Indexed: 02/04/2023] Open
Abstract
This study aimed to propose an alternative technological solution for manufacturing fiberboard panels using a modified hot-pressing regime and hydrolysis lignin as the main binder. The main novelty of the research is the optimized adhesive system composed of unmodified hydrolysis lignin and reduced phenol–formaldehyde (PF) resin content. The fiberboard panels were fabricated in the laboratory with a very low PF resin content, varying from 1% to 3.6%, and hydrolysis lignin addition levels varying from 7% to 10.8% (based on the dry wood fibers). A specific two-stage hot-pressing regime, including initial low pressure of 1.2 MPa and subsequent high pressure of 4 MPa, was applied. The effect of binder content and PF resin content in the adhesive system on the main properties of fiberboards (water absorption, thickness swelling, bending strength, modulus of elasticity, and internal bond strength) was investigated, and appropriate optimization was performed to define the optimal content of PF resin and hydrolysis lignin for complying with European standards. It was concluded that the proposed technology is suitable for manufacturing fiberboard panels fulfilling the strictest EN standard. Markedly, it was shown that for the production of this type of panels, the minimum total content of binders should be 10.6%, and the PF resin content should be at least 14% of the adhesive system.
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Affiliation(s)
- Viktor Savov
- Faculty of Forest Industry, University of Forestry, 1797 Sofia, Bulgaria
- Correspondence: (V.S.); (P.A.)
| | - Ivo Valchev
- Faculty of Chemical Technologies, University of Chemical Technology and Metallurgy, 1757 Sofia, Bulgaria; (I.V.); (I.Y.)
| | - Petar Antov
- Faculty of Forest Industry, University of Forestry, 1797 Sofia, Bulgaria
- Correspondence: (V.S.); (P.A.)
| | - Ivaylo Yordanov
- Faculty of Chemical Technologies, University of Chemical Technology and Metallurgy, 1757 Sofia, Bulgaria; (I.V.); (I.Y.)
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Tureková I, Ivanovičová M, Harangózo J, Gašpercová S, Marková I. Experimental Study of the Influence of Selected Factors on the Particle Board Ignition by Radiant Heat Flux. Polymers (Basel) 2022; 14:polym14091648. [PMID: 35566818 PMCID: PMC9100599 DOI: 10.3390/polym14091648] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 04/12/2022] [Accepted: 04/14/2022] [Indexed: 01/27/2023] Open
Abstract
Particleboards are used in the manufacturing of furniture and are often part of the interior of buildings. In the event of a fire, particleboards are a substantial part of the fuel in many building fires. The aim of the article is to monitor the effect of radiant heat on the surface of particle board according to the modified procedure ISO 5657: 1997. The significance of the influence of heat flux density and particle board properties on its thermal resistance (time to ignition) was monitored. Experimental samples were used particle board without surface treatment, with thicknesses of 12, 15, and 18 mm. The samples were exposed to a heat flux from 40 to 50 kW·m−2. The experimental results are the initiation characteristics such as of the ignition temperature and the weight loss. The determined factors influencing the time to ignition and weight loss were the thickness and density of the plate material, the density of the radiant heat flux and the distance of the particle board from the radiant source (20, 40, and 60 mm). The obtained results show a significant dependence of the time to ignition on the thickness of the sample and on the heat flux density. The weight loss is significantly dependent on the thickness of the particle board. Monitoring the influence of time to ignition from sample distance confirmed a statistically significant dependence. As the distance of the sample from the source increased, the time to ignition decreased linearly. As the distance of the sample from the source increased, the time to ignition increased.
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Affiliation(s)
- Ivana Tureková
- Department of Technology and Information Technologies, Faculty of Education, Constantine the Philosopher University in Nitra, Tr. A. Hlinku 1, 949 74 Nitra, Slovakia; (I.T.); (M.I.); (J.H.)
| | - Martina Ivanovičová
- Department of Technology and Information Technologies, Faculty of Education, Constantine the Philosopher University in Nitra, Tr. A. Hlinku 1, 949 74 Nitra, Slovakia; (I.T.); (M.I.); (J.H.)
| | - Jozef Harangózo
- Department of Technology and Information Technologies, Faculty of Education, Constantine the Philosopher University in Nitra, Tr. A. Hlinku 1, 949 74 Nitra, Slovakia; (I.T.); (M.I.); (J.H.)
| | - Stanislava Gašpercová
- Department of Fire Engineering, Faculty of Security Engineering, University of Žilina, Univerzitná 1, 010 26 Zilina, Slovakia;
| | - Iveta Marková
- Department of Fire Engineering, Faculty of Security Engineering, University of Žilina, Univerzitná 1, 010 26 Zilina, Slovakia;
- Correspondence: ; Tel.: +421-041-513-6799
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Wibowo ES, Park BD, Causin V. Recent advances in urea–formaldehyde resins: converting crystalline thermosetting polymers back to amorphous ones. POLYM REV 2021. [DOI: 10.1080/15583724.2021.2014520] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Eko Setio Wibowo
- Department of Wood and Paper Science, Kyungpook National University, Daegu, Republic of Korea
| | - Byung-Dae Park
- Department of Wood and Paper Science, Kyungpook National University, Daegu, Republic of Korea
| | - Valerio Causin
- Departimento di Scienze Chimiche, Università di Padova, Padova, Italy
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10
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Gonçalves S, Ferra J, Paiva N, Martins J, Carvalho LH, Magalhães FD. Lignosulphonates as an Alternative to Non-Renewable Binders in Wood-Based Materials. Polymers (Basel) 2021; 13:polym13234196. [PMID: 34883699 PMCID: PMC8659965 DOI: 10.3390/polym13234196] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 11/22/2021] [Indexed: 11/16/2022] Open
Abstract
Lignin is a widely abundant renewable source of phenolic compounds. Despite the growing interest on using it as a substitute for its petroleum-based counterparts, only 1 to 2% of the global lignin production is used for obtaining value-added products. Lignosulphonates (LS), derived from the sulphite pulping process, account for 90% of the total market of commercial lignin. The most successful industrial attempts to use lignin for wood adhesives are based on using this polymer as a partial substitute in phenol-formaldehyde or urea-formaldehyde resins. Alternatively, formaldehyde-free adhesives with lignin and lignosulphonates have also been developed with promising results. However, the low number of reactive sites available in lignin's aromatic ring and high polydispersity have hindered its application in resin synthesis. Currently, finding suitable crosslinkers for LS and decreasing the long pressing time associated with lignin adhesives remains a challenge. Thus, several methods have been proposed to improve the reactivity of lignin molecules. In this paper, techniques to extract, characterize, as well as improve the reactivity of LS are addressed. The most recent advances in the application of LS in wood adhesives, with and without combination with formaldehyde, are also reviewed.
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Affiliation(s)
- Sofia Gonçalves
- LEPABE–Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; (S.G.); (J.M.); (L.H.C.)
| | - João Ferra
- Sonae Arauco Portugal S.A., Lugar do Espido—Via Norte, 4470-177 Porto, Portugal; (J.F.); (N.P.)
| | - Nádia Paiva
- Sonae Arauco Portugal S.A., Lugar do Espido—Via Norte, 4470-177 Porto, Portugal; (J.F.); (N.P.)
| | - Jorge Martins
- LEPABE–Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; (S.G.); (J.M.); (L.H.C.)
- DEMad–Departamento de Engenharia de Madeiras, Instituto Politécnico de Viseu, Campus Politécnico de Repeses, 3504-510 Viseu, Portugal
| | - Luísa H. Carvalho
- LEPABE–Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; (S.G.); (J.M.); (L.H.C.)
- DEMad–Departamento de Engenharia de Madeiras, Instituto Politécnico de Viseu, Campus Politécnico de Repeses, 3504-510 Viseu, Portugal
| | - Fernão D. Magalhães
- LEPABE–Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; (S.G.); (J.M.); (L.H.C.)
- Correspondence:
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11
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Saito K, Hirabayashi Y, Yamanaka S. Reduction of formaldehyde emission from urea-formaldehyde resin with a small quantity of graphene oxide. RSC Adv 2021; 11:32830-32836. [PMID: 35493570 PMCID: PMC9042194 DOI: 10.1039/d1ra06717f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 09/28/2021] [Indexed: 11/21/2022] Open
Abstract
Graphene oxide (GO) has theoretically been identified as a candidate for adsorbing formaldehyde molecules. However, whether GO can actually serve as a scavenger for formaldehyde resin adhesives must be experimentally verified due to the complex interaction between GO and formaldehyde molecules in the presence of resin, the competition between the formaldehyde emission rate and its adsorption rate on the scavenger, and other complications. From the results from this study we experimentally demonstrate that GO synthesised by the improved Hummers' method is a powerful scavenger for a urea-formaldehyde (UF) resin. We investigate the effect of the added amount of GO on the formaldehyde emission from UF resin. The emission from the UF/GO composite resin is 0.22 ± 0.03 mg L-1, which is an 81.5% reduction compared to that of the control UF resin when adding 0.20 wt% GO into the UF resin. However, adding higher amounts of GO (more than 0.20 wt%) increases the formaldehyde emission and the emission approaches that of pure UF resin (1.19 ± 0.36 mg L-1). This is likely due to the more acidic pH of the composite, which may lead to a faster curing reaction of the UF resin and acceleration of the emission.
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Affiliation(s)
- Kazuki Saito
- Division of Applied Sciences, Muroran Institute of Technology Mizumoto-cho 27-1 Muroran 050-8585 Japan
| | - Yasushi Hirabayashi
- Forest Products Research Institute, Hokkaido Research Organization Nishikagura 1-10 Asahikawa 071-0198 Japan
| | - Shinya Yamanaka
- Division of Applied Sciences, Muroran Institute of Technology Mizumoto-cho 27-1 Muroran 050-8585 Japan
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12
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Mechanical Properties and Formaldehyde Release of Particleboard Made with Lignin-Based Adhesives. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11188720] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The aim of this research was to evaluate the potential of magnesium lignosulfonate as adhesive in particleboard manufacturing. Diphenylmethane diisocyanate (PMDI) between 1% and 3% and glucose (1% of the lignosulfonate content) were added as potential cross-linkers in the adhesive formulations. Mixed beech and spruce wood, 30% beech wood and 70% spruce wood, were employed for the configuration of the panel structure. The density, mechanical properties and formaldehyde emission of single-layer particleboard were investigated. Spectroscopic analysis (FTIR) revealed structural changes brought by oxidation that may indicate depolymerization by the splitting of C-O-C bonds and formation of carbonyl groups. Mechanical properties were improved, and the highest average values were recorded for panels having as adhesives oxidized lignin with cross-linkers as follow: 15 N/mm2 (MOR), 3320 N/mm2 (MOE) and 0.48 N/mm2 (IB). The density profile presented higher values for faces in case of oxidized lignin panels. Changes were observed for oxidized lignin with cross-linker panels wherein the core had higher values. The results showed that the panels manufactured with adhesives composed of oxidized lignosulfonate (20% of the dried wood particles weight) and the addition of PMDI and glucose in various percentages have a positive influence on their formaldehyde release and mechanical properties requested by EN 312 (2004) standard.
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13
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Properties of Eco-Friendly Particleboards Bonded with Lignosulfonate-Urea-Formaldehyde Adhesives and pMDI as a Crosslinker. MATERIALS 2021; 14:ma14174875. [PMID: 34500965 PMCID: PMC8432716 DOI: 10.3390/ma14174875] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 08/12/2021] [Accepted: 08/25/2021] [Indexed: 01/25/2023]
Abstract
The purpose of this study was to evaluate the feasibility of using magnesium and sodium lignosulfonates (LS) in the production of particleboards, used pure and in mixtures with urea-formaldehyde (UF) resin. Polymeric 4,4′-diphenylmethane diisocyanate (pMDI) was used as a crosslinker. In order to evaluate the effect of gradual replacement of UF by magnesium lignosulfonate (MgLS) or sodium lignosulfonate (NaLS) on the physical and mechanical properties, boards were manufactured in the laboratory with LS content varying from 0% to 100%. The effect of LS on the pH of lignosulfonate-urea-formaldehyde (LS-UF) adhesive compositions was also investigated. It was found that LS can be effectively used to adjust the pH of uncured and cured LS-UF formulations. Particleboards bonded with LS-UF adhesive formulations, comprising up to 30% LS, exhibited similar properties when compared to boards bonded with UF adhesive. The replacement of UF by both LS types substantially deteriorated the water absorption and thickness swelling of boards. In general, NaLS-UF-bonded boards had a lower formaldehyde content (FC) than MgLS-UF and UF-bonded boards as control. It was observed that in the process of manufacturing boards using LS adhesives, increasing the proportion of pMDI in the adhesive composition can significantly improve the mechanical properties of the boards. Overall, the boards fabricated using pure UF adhesives exhibited much better mechanical properties than boards bonded with LS adhesives. Markedly, the boards based on LS adhesives were characterised by a much lower FC than the UF-bonded boards. In the LS-bonded boards, the FC is lower by 91.1% and 56.9%, respectively, compared to the UF-bonded boards. The boards bonded with LS and pMDI had a close-to-zero FC and reached the super E0 emission class (≤1.5 mg/100 g) that allows for defining the laboratory-manufactured particleboards as eco-friendly composites.
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Antov P, Savov V, Trichkov N, Krišťák Ľ, Réh R, Papadopoulos AN, Taghiyari HR, Pizzi A, Kunecová D, Pachikova M. Properties of High-Density Fiberboard Bonded with Urea-Formaldehyde Resin and Ammonium Lignosulfonate as a Bio-Based Additive. Polymers (Basel) 2021; 13:polym13162775. [PMID: 34451315 PMCID: PMC8398458 DOI: 10.3390/polym13162775] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Accepted: 08/15/2021] [Indexed: 11/16/2022] Open
Abstract
The potential of ammonium lignosulfonate (ALS) as an eco-friendly additive to urea–formaldehyde (UF) resin for manufacturing high-density fiberboard (HDF) panels with acceptable properties and low free formaldehyde emission was investigated in this work. The HDF panels were manufactured in the laboratory with very low UF resin content (4%) and ALS addition levels varying from 4% to 8% based on the mass of the dry wood fibers. The press factor applied was 15 s·mm−1. The physical properties (water absorption and thickness swelling), mechanical properties (bending strength, modulus of elasticity, and internal bond strength), and free formaldehyde emission were evaluated in accordance with the European standards. In general, the developed HDF panels exhibited acceptable physical and mechanical properties, fulfilling the standard requirements for HDF panels for use in load-bearing applications. Markedly, the laboratory-produced panels had low free formaldehyde emission ranging from 2.0 to 1.4 mg/100 g, thus fulfilling the requirements of the E0 and super E0 emission grades and confirming the positive effect of ALS as a formaldehyde scavenger. The thermal analyses performed, i.e., differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), and derivative thermogravimetry (DTG), also confirmed the main findings of the research. It was concluded that ALS as a bio-based, formaldehyde-free adhesive can be efficiently utilized as an eco-friendly additive to UF adhesive formulations for manufacturing wood-based panels under industrial conditions.
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Affiliation(s)
- Petar Antov
- Faculty of Forest Industry, University of Forestry, 1797 Sofia, Bulgaria; (V.S.); (N.T.)
- Correspondence: (P.A.); (Ľ.K.)
| | - Viktor Savov
- Faculty of Forest Industry, University of Forestry, 1797 Sofia, Bulgaria; (V.S.); (N.T.)
| | - Neno Trichkov
- Faculty of Forest Industry, University of Forestry, 1797 Sofia, Bulgaria; (V.S.); (N.T.)
| | - Ľuboš Krišťák
- Faculty of Wood Sciences and Technology, Technical University in Zvolen, 96001 Zvolen, Slovakia;
- Correspondence: (P.A.); (Ľ.K.)
| | - Roman Réh
- Faculty of Wood Sciences and Technology, Technical University in Zvolen, 96001 Zvolen, Slovakia;
| | - Antonios N. Papadopoulos
- Laboratory of Wood Chemistry and Technology, Department of Forestry and Natural Environment, International Hellenic University, GR-661 00 Drama, Greece;
| | - Hamid R. Taghiyari
- Wood Science and Technology Department, Faculty of Materials Engineering & New Technologies, Shahid Rajaee Teacher Training University, Tehran 16788-15811, Iran;
| | - Antonio Pizzi
- LERMAB-ENSTIB, University of Lorraine, 27 Rue Philippe Seguin, 88000 Epinal, France;
| | - Daniela Kunecová
- Faculty of Engineering, Slovak University of Agriculture in Nitra, 94976 Nitra, Slovakia;
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Kristak L, Kubovský I, Réh R. New Challenges in Wood and Wood-Based Materials. Polymers (Basel) 2021; 13:polym13152538. [PMID: 34372140 PMCID: PMC8348594 DOI: 10.3390/polym13152538] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 07/26/2021] [Indexed: 12/05/2022] Open
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Arias A, Feijoo G, Moreira MT. Evaluation of Starch as an Environmental-Friendly Bioresource for the Development of Wood Bioadhesives. Molecules 2021; 26:4526. [PMID: 34361679 PMCID: PMC8347426 DOI: 10.3390/molecules26154526] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 07/24/2021] [Accepted: 07/24/2021] [Indexed: 12/05/2022] Open
Abstract
The environment is a very complex and fragile system in which multiple factors of different nature play an important role. Pollution, together with resource consumption, is one of the main causes of the environmental problems currently affecting the planet. In the search for alternative production processes, the use of renewable resources seeks a way to satisfy the demands of resource consumption based on the premises of lower environment impact and less damage to human health. In the wood sector, the panel manufacturing process is based on the use of formaldehyde-based resins. However, their poor moisture resistance leads to hydrolysis of amino-methylene bonds, which induces formaldehyde emissions throughout the lifetime of the wood panel. This manuscript investigates the environmental profile associated with different wood bioadhesives based on starch functionalization as a renewable alternative to formaldehyde resins. Considering that this is a process under development, the conceptual design of the full-scale process will be addressed by process modeling and the environmental profile will be assessed using life cycle assessment methodology. A comparative study with synthetic resins will provide useful information for modify their development to become real alternatives in the wood-based panel industry. The results obtained show the enormous potential of starch bioadhesives, as their environmental impact values are lower compared to those based on petrochemicals. However, certain improvements in the energy process requirements and in the chemical agents used could be developed to provide even better results.
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Affiliation(s)
- Ana Arias
- CRETUS, Department of Chemical Engineering, School of Engineering, Universidade de Santiago de Compostela, 15705 Santiago de Compostela, Spain; (G.F.); (M.T.M.)
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Song J, Chen S, Yi X, Zhao X, Zhang J, Liu X, Liu B. Preparation and Properties of the Urea-Formaldehyde Res-In/Reactive Halloysite Nanocomposites Adhesive with Low-Formaldehyde Emission and Good Water Resistance. Polymers (Basel) 2021; 13:polym13142224. [PMID: 34300982 PMCID: PMC8309405 DOI: 10.3390/polym13142224] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 06/28/2021] [Accepted: 06/29/2021] [Indexed: 02/03/2023] Open
Abstract
Low-cost urea formaldehyde resin (UF)/reactive halloysite nanotubes (HNTs) nanocomposite adhesive was prepared successfully via in situ polymerization. The HNTs were modified to improve its compatibility with polymer. The XRD and FTIR results showed that physical and chemical interaction between the HNTs and polymer resin influenced the structure of UF owing to the functional groups on the HNTs. It is found from SEM images that the modified HNTs could be dispersed uniformly in the resin and the nanocomposite particles were spherical. The performance experiment confirmed that thermal stability of nanocomposite increased largely, formaldehyde emission of UF wood adhesive reduced 62%, and water resistance of UF wood adhesive improved by 84%. Meanwhile, the content of HNTs on the nanocomposites could be up to 60 wt %. The mechanism of the nanocomposites based on the reactive HNTs was proposed. The approach of the preparation could supply an idea to prepare other polymer/clay nanocomposites.
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Affiliation(s)
- Jingbiao Song
- Shandong Provincial Key Laboratory of Processing and Testing Technology of Glass and Functional Ceramics, School of Material Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China;
| | - Shiwei Chen
- Shandong Provincial Key Laboratory of Processing and Testing Technology of Glass and Functional Ceramics, School of Material Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China;
- Shandong Key Laboratory for Special Silicon-containing Material, Advanced Materials Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China; (X.Y.); (X.Z.); (J.Z.); (X.L.); (B.L.)
- Correspondence:
| | - Xibin Yi
- Shandong Key Laboratory for Special Silicon-containing Material, Advanced Materials Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China; (X.Y.); (X.Z.); (J.Z.); (X.L.); (B.L.)
| | - Xinfu Zhao
- Shandong Key Laboratory for Special Silicon-containing Material, Advanced Materials Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China; (X.Y.); (X.Z.); (J.Z.); (X.L.); (B.L.)
| | - Jing Zhang
- Shandong Key Laboratory for Special Silicon-containing Material, Advanced Materials Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China; (X.Y.); (X.Z.); (J.Z.); (X.L.); (B.L.)
| | - Xiaochan Liu
- Shandong Key Laboratory for Special Silicon-containing Material, Advanced Materials Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China; (X.Y.); (X.Z.); (J.Z.); (X.L.); (B.L.)
| | - Benxue Liu
- Shandong Key Laboratory for Special Silicon-containing Material, Advanced Materials Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China; (X.Y.); (X.Z.); (J.Z.); (X.L.); (B.L.)
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Podlena M, Böhm M, Saloni D, Velarde G, Salas C. Tuning the Adhesive Properties of Soy Protein Wood Adhesives with Different Coadjutant Polymers, Nanocellulose and Lignin. Polymers (Basel) 2021; 13:1972. [PMID: 34203736 PMCID: PMC8232160 DOI: 10.3390/polym13121972] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 06/08/2021] [Accepted: 06/09/2021] [Indexed: 12/04/2022] Open
Abstract
Commercial wood adhesives are based on products that contain formaldehyde; however, environmental and health concerns about formaldehyde emissions from wood products have influenced research and development efforts in order to find alternative, formaldehyde-free products for wood adhesives. In this work, different soy protein-based wood adhesives are proposed, and their performance is compared to commercial urea formaldehyde (UF) adhesive. Soy protein-based wood adhesives were prepared using either soy protein isolate (SPI) or soy protein flour (SF) with different coadjutant polymers: polyethylene oxide (PEO), hydroxypropyl methylcellulose (HPMC), cellulose nanofibrils (CNF) or polyvinyl alcohol (PVA) with and without addition of kraft lignin. The effects of the type of soy protein, solids content, coadjutant polymer and lignin addition were investigated. The wood adhesive formulations were tested on the bonding of hardwood (white maple) and softwood (southern yellow pine) and the dry shear strength of test specimens was measured according to method ASTM D905-08. The adhesive formulations with SPI achieved significantly higher values than those with SF. The dry shear strength of the adhesives varies depending on the coadjutant polymer, the wood species and the addition of lignin.
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Affiliation(s)
- Milan Podlena
- Department of Materials Engineering and Chemistry, Czech Technical University in Prague, Thákurova 7, 166 29 Prague, Czech Republic;
| | - Martin Böhm
- Department of Materials Engineering and Chemistry, Czech Technical University in Prague, Thákurova 7, 166 29 Prague, Czech Republic;
| | - Daniel Saloni
- Department of Forest Biomaterials, NC State University, 2820 Faucette Dr, Raleigh, NC 27607, USA; (D.S.); (G.V.); (C.S.)
| | - Guillermo Velarde
- Department of Forest Biomaterials, NC State University, 2820 Faucette Dr, Raleigh, NC 27607, USA; (D.S.); (G.V.); (C.S.)
| | - Carlos Salas
- Department of Forest Biomaterials, NC State University, 2820 Faucette Dr, Raleigh, NC 27607, USA; (D.S.); (G.V.); (C.S.)
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Mirski R, Dziurka D, Kuliński M, Derkowski A. Lightweight Insulation Boards Based on Lignocellulosic Particles Glued with Agents of Natural Origin. MATERIALS 2021; 14:ma14123219. [PMID: 34200902 PMCID: PMC8230460 DOI: 10.3390/ma14123219] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 06/08/2021] [Accepted: 06/09/2021] [Indexed: 11/16/2022]
Abstract
In this study, the possibility of using adhesives of natural origin for the manufacture of wood fiber-based lightweight panels was investigated. The boards, of a density ranging from 150 to 250 kg/m3, were glued together using commercial urea–formaldehyde resin (control board), solutions of rye flour and potato starch and two types of starch: oxidized and gelatinized. The density and density profile, compressive strength, modulus of elasticity, acoustic properties and thermal conductivity were determined in the produced boards. These studies show that when food components are used as binding agents in the manufacture of lightweight wood fiberboards, the properties obtained can be comparable with those of commercial boards manufactured using synthetic agents.
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Rantuch P, Martinka J, Ház A. The Evaluation of Torrefied Wood Using a Cone Calorimeter. Polymers (Basel) 2021; 13:polym13111748. [PMID: 34071814 PMCID: PMC8199449 DOI: 10.3390/polym13111748] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 05/23/2021] [Accepted: 05/23/2021] [Indexed: 12/15/2022] Open
Abstract
This study focuses on the energy potential and combustion process of torrefied wood. Samples were prepared through the torrefaction of five types of wood: Ash, beech, oak, pine and spruce. These were heated for 2 h at a temperature of 300 °C under a nitrogen atmosphere. Torrefied wood was prepared from wood samples with dimensions of 100 × 100 × 20 mm3. These dimensions have enabled investigation of torrefied wood combustion in compact form. The effect of the external heat flux on the combustion of the samples was measured using a cone calorimeter. The observed parameters, include initiation times, heat release rate and combustion efficiency. The results show that increasing the external heat flux decreases the evenness of combustion of torrefied wood. At the same time, it increases the combustion efficiency, which reached an average value of approximately 72% at 20 kW m-2, 81% at 30 kW m-2 and 90% at 40 kW m-2. The calculated values of critical heat flux of the individual samples ranged from 4.67 kW m-2 to 15.2 kW m-2, the thermal response parameter ranged from 134 kW s0.5 m-2 to 297 kW s0.5 m-2 and calculated ignition temperature ranged from 277 °C to 452 °C. Obtained results are useful both for energy production field and for fire safety risk assessment of stored torrefied wood.
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Affiliation(s)
- Peter Rantuch
- Faculty of Materials Science and Technology in Trnava, Slovak University of Technology in Bratislava, 917 24 Trnava, Slovakia;
- Correspondence: ; Tel.: +421-910-993-650
| | - Jozef Martinka
- Faculty of Materials Science and Technology in Trnava, Slovak University of Technology in Bratislava, 917 24 Trnava, Slovakia;
| | - Aleš Ház
- Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, 812 37 Bratislava, Slovakia;
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Availability and Applicability of Wood and Crop Residues for the Production of Wood Composites. FORESTS 2021. [DOI: 10.3390/f12050641] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Due to high levels of volatility in both the agricultural and the forestry commodity markets, specifically, of timber and agricultural crops, it is important to identify the risks associated with the stability of supplies necessary for the production of composite materials in the Czech Republic. This study aims to accurately estimate the availability of selected raw materials that contain lignocellulose over the next 20 years. In addition, their suitability for the production of composite materials is assessed based on their physical properties. Furthermore, in the event of scarcity involving timber in the European Union, recycled wood and post-harvest residues could replace conventional raw materials in wood-based composites such as particleboards and chipboards. The viable potential of Czech forests is predicted to be between 740 and 750 million cubic meters of timber. For agricultural crops, it is estimated at 0.9 million hectares of wheat and 0.5 million hectares of canola under the current EU biofuel policy and at 0.4 million hectares if this policy is removed. According to moisture and fibre analyses carried out in our study, the most suitable candidate for wood-based composites production is soft wood.
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Thermal and Mechanical Properties of Green Insulation Composites Made from Cannabis and Bark Residues. JOURNAL OF COMPOSITES SCIENCE 2021. [DOI: 10.3390/jcs5050132] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The objective of this paper was to investigate the technical feasibility of manufacturing low density insulation particleboards that were made from two renewable resources, namely hemp fibers (Cannabis sativa) and pine tree bark, which were bonded with a non-toxic methyl cellulose glue, as a binder. Four types of panels were made, which consisted of varying mixtures of tree bark and hemp fibers (tree bark to hemp fibers percentages of 90:10, 80:20, 70:30, and 60:40). An additional set of panels was made, consisting only of bark. The results showed that addition of hemp fibers to furnish improved mechanical properties of boards to reach an acceptable level. The thermal conductivity unfavorably increased as hemp content increased, though all values were still within the acceptable range. Based on cluster analysis, board type 70:30 (with 30% hemp content) produced the highest mechanical properties as well as the optimal thermal conductivity value. It is concluded that low density insulation boards can be successfully produced using these waste raw materials.
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Abstract
Technologies for the isolation of lignin from pulping process streams are reviewed in this article. Based on published data, the WestVaco process, the LignoBoost process, the LigoForce SystemTM and the SLRP process are reviewed and discussed for the isolation of lignin from Kraft black liquor. The three new processes that have now joined the WestVaco process are compared from the perspective of product quality. Further, isolation processes of lignosulfonates from spent sulfite liquor are reviewed. The limitation for this review is that data are only available from lab scale and pilot scale experiments and not from industrial processes. Key output of this paper is a technology summary of the state of the art processes for technical lignins, showing the pros and cons of each process.
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Experimental Study of Straw-Based Eco-Panel Using a Small Ignition Initiator. Polymers (Basel) 2021; 13:polym13081344. [PMID: 33924055 PMCID: PMC8072763 DOI: 10.3390/polym13081344] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 04/15/2021] [Accepted: 04/18/2021] [Indexed: 11/27/2022] Open
Abstract
Straw, a natural cellulose-based material, has become part of building elements. Eco-panels, compressed straw in a cardboard casing, is used as building insulation. Eco-panel is a secondary product with excellent insulating properties. If suitably fire-treated (insulation and covering), straw panels’ fire resistance may be increased. This contribution deals with monitoring the behavior of eco-panels exposed to a small ignition initiator (flame). The samples consisted of compressed straw boards coated with a 40 mm thick cardboard. Samples were exposed to a flame for 5 and 10 min. The influence of the selected factors (size of the board, orientation of flame with the sample) were compared on the basis of experimentally obtained data: mass loss. The results obtained do not show a statistically significant influence of the position of the sample and the initiating source (flame). The results presented in the article confirm the justifiability of fire tests. As the results of the experiments prove, the position of a small burner for igniting such material is also important. Such weakness of the material can also be eliminated by design solutions in the construction. The experiment on larger samples also confirmed the justifiability of fire tests along with the need for flame retardancy of such material for its safe application in construction.
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Abstract
Wood composites are the key material for a number of structural and non-structural applications for interior and exterior purposes, such as furniture, construction, floorings, windows and doors, etc [...]
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Kačíková D, Kubovský I, Gaff M, Kačík F. Changes of Meranti, Padauk, and Merbau Wood Lignin during the ThermoWood Process. Polymers (Basel) 2021; 13:993. [PMID: 33804876 PMCID: PMC8037302 DOI: 10.3390/polym13070993] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 03/16/2021] [Accepted: 03/18/2021] [Indexed: 12/12/2022] Open
Abstract
Thermal modification is an environmentally friendly process in which technological properties of wood are modified using thermal energy without adding chemicals, the result of which is a value-added product. Wood samples of three tropical wood species (meranti, padauk, and merbau) were thermally treated according to the ThermoWood process at various temperatures (160, 180, 210 °C) and changes in isolated lignin were evaluated by nitrobenzene oxidation (NBO), Fourier-transform infrared spectroscopy (FTIR), and size exclusion chromatography (SEC). New data on the lignins of the investigated wood species were obtained, e.g., syringyl to guaiacyl ratio values (S/G) were 1.21, 1.70, and 3.09, and molecular weights were approx. 8600, 4300, and 8300 g·mol-1 for meranti, padauk, and merbau, respectively. Higher temperatures cause a decrease of methoxyls and an increase in C=O groups. Simultaneous degradation and condensation reactions in lignin occur during thermal treatment, the latter prevailing at higher temperatures.
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Affiliation(s)
- Danica Kačíková
- Faculty of Wood Sciences and Technology, Technical University in Zvolen, T.G. Masaryka 24, 960 01 Zvolen, Slovakia; (D.K.); (F.K.)
| | - Ivan Kubovský
- Faculty of Wood Sciences and Technology, Technical University in Zvolen, T.G. Masaryka 24, 960 01 Zvolen, Slovakia; (D.K.); (F.K.)
| | - Milan Gaff
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences in Prague, Kamýcká 129, 165 00 Praha 6-Suchdol, Czech Republic;
| | - František Kačík
- Faculty of Wood Sciences and Technology, Technical University in Zvolen, T.G. Masaryka 24, 960 01 Zvolen, Slovakia; (D.K.); (F.K.)
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Antov P, Krišt’ák L, Réh R, Savov V, Papadopoulos AN. Eco-Friendly Fiberboard Panels from Recycled Fibers Bonded with Calcium Lignosulfonate. Polymers (Basel) 2021; 13:639. [PMID: 33669944 PMCID: PMC7924858 DOI: 10.3390/polym13040639] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 02/19/2021] [Accepted: 02/19/2021] [Indexed: 01/05/2023] Open
Abstract
The potential of using residual softwood fibers from the pulp and paper industry for producing eco-friendly, zero-formaldehyde fiberboard panels, bonded with calcium lignosulfonate (CLS) as a lignin-based, formaldehyde free adhesive, was investigated in this work. Fiberboard panels were manufactured in the laboratory by applying CLS addition content ranging from 8% to 14% (on the dry fibers). The physical and mechanical properties of the developed composites, i.e., water absorption (WA), thickness swelling (TS), modulus of elasticity (MOE), bending strength (MOR), as well as the free formaldehyde emission, were evaluated according to the European norms. In general, only the composites, developed with 14% CLS content, exhibited MOE and MOR values, comparable with the standard requirements for medium-density fiberboards (MDF) for use in dry conditions. All laboratory-produced composites demonstrated significantly deteriorated moisture-related properties, i.e., WA (24 h) and TS (24 h), which is a major drawback. Noticeably, the fiberboards produced had a close-to-zero formaldehyde content, reaching the super E0 class (≤1.5 mg/100 g), with values, ranging from 0.8 mg/100 g to 1.1 mg/100 g, i.e., equivalent to formaldehyde emission of natural wood. The amount of CLS adhesive had no significant effect on formaldehyde content.
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Affiliation(s)
- Petar Antov
- Faculty of Forest Industry, University of Forestry, 1797 Sofia, Bulgaria;
| | - L’uboš Krišt’ák
- Faculty of Wood Sciences and Technology, Technical University in Zvolen, 96001 Zvolen, Slovakia; (L.K.); (R.R.)
| | - Roman Réh
- Faculty of Wood Sciences and Technology, Technical University in Zvolen, 96001 Zvolen, Slovakia; (L.K.); (R.R.)
| | - Viktor Savov
- Faculty of Forest Industry, University of Forestry, 1797 Sofia, Bulgaria;
| | - Antonios N. Papadopoulos
- Laboratory of Wood Chemistry and Technology, Department of Forestry and Natural Environment, International Hellenic University, GR-661 00 Drama, Greece
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