scholarly journals Lignosulphonates as an Alternative to Non-Renewable Binders in Wood-Based Materials

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4196
Author(s):  
Sofia Gonçalves ◽  
João Ferra ◽  
Nádia Paiva ◽  
Jorge Martins ◽  
Luísa H. Carvalho ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Aromatic Ring ◽  
Phenol Formaldehyde ◽  
Urea Formaldehyde ◽  
Value Added ◽  
Wood Adhesives ◽  
Renewable Source ◽  
Pressing Time ◽  
Value Added Products ◽  
Total Market

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.

scholarly journals Methods to improve lignin’s reactivity as a phenol substitute and as replacement for other phenolic compounds: A brief review

BioResources ◽  
2011 ◽  
Vol 6 (3) ◽  
pp. 3515-3525 ◽  
Author(s):  
Lihong Hu ◽  
Hui Pan ◽  
Yonghong Zhou ◽  
Meng Zhang
Keyword(s):  
Phenolic Compounds ◽  
Chemical Structure ◽  
Phenol Formaldehyde ◽  
Paper Industry ◽  
Value Added ◽  
Pulp And Paper Industry ◽  
Lignin Modification ◽  
Modified Lignin ◽  
Lignin Macromolecule ◽  
Value Added Products

Lignin is readily available as a by-product from the pulp and paper industry. It is considered to be a promising substitute for phenol in phenol-formaldehyde (PF) resin synthesis, given the increasing concerns of the shortage of fossil resources and the environmental impact from petroleum-based products. One hurdle that prevents the commercial utilization of lignin is its low reactivity due to its chemical structure. Many efforts have been made to improve its reactivity by modification and/or depolymerization of lignin molecules. Methylolation and phenolation are the two most studied modification approaches aimed at introducing reactive functional groups to lignin molecules. Modified lignin from these two methods could partially replace phenol in PF resin synthesis. Demethylation of lignin could effectively increase the reactivity of lignin by forming catechol moieties in the lignin macromolecule. Other methods, including reduction, oxidation, and hydrolysis, have also been studied to improve the reactivity of lignin as well as to produce phenolic compounds from lignin. Most current methods of lignin modification are not economically attractive. One can expect that efforts will be continued, aimed at improving the utilization of lignin for value-added products.

scholarly journals Environmentally-Friendly High-Density Polyethylene-Bonded Plywood Panels

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1166 ◽  
Author(s):  
Pavlo Bekhta ◽  
Ján Sedliačik
Keyword(s):  
Mechanical Properties ◽  
Hot Pressing ◽  
High Density Polyethylene ◽  
Phenol Formaldehyde ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Core Layer ◽  
High Density ◽  
Pressing Pressure ◽  
Pressing Time

Thermoplastic films exhibit good potential to be used as adhesives for the production of veneer-based composites. This work presents the first effort to develop and evaluate composites based on alder veneers and high-density polyethylene (HDPE) film. The effects of hot-pressing temperature (140, 160, and 180 °C), hot-pressing pressure (0.8, 1.2, and 1.6 MPa), hot-pressing time (1, 2, 3, and 5 min), and type of adhesives on the physical and mechanical properties of alder plywood panels were investigated. The effects of these variables on the core-layer temperature during the hot pressing of multiplywood panels using various adhesives were also studied. Three types of adhesives were used: urea–formaldehyde (UF), phenol–formaldehyde (PF), and HDPE film. UF and PF adhesives were used for the comparison. The findings of this work indicate that formaldehyde-free HDPE film adhesive gave values of mechanical properties of alder plywood panels that are comparable to those obtained with traditional UF and PF adhesives, even though the adhesive dosage and pressing pressure were lower than when UF and PF adhesives were used. The obtained bonding strength values of HDPE-bonded alder plywood panels ranged from 0.74 to 2.38 MPa and met the European Standard EN 314-2 for Class 1 plywood. The optimum conditions for the bonding of HDPE plywood were 160 °C, 0.8 MPa, and 3 min.

Influence of Nanoclay on Phenol-Formaldehyde and Phenol-Urea-Formaldehyde Resins for Wood Adhesives

2010 ◽  
Vol 24 (8-10) ◽  
pp. 1567-1576 ◽  
Author(s):  
H. Lei ◽  
G. Du ◽  
A. Pizzi ◽  
A. Celzard ◽  
Q. Fang
Keyword(s):  
Phenol Formaldehyde ◽  
Urea Formaldehyde ◽  
Wood Adhesives

scholarly journals Biorefinery of lignocellulosic biopolymers

2016 ◽  
Vol 2 (1) ◽  
pp. 79 ◽  
Author(s):  
Bruna Steil Boneberg ◽  
Grazielle Dias Machado ◽  
Davi Friedrich Santos ◽  
Fernando Gomes ◽  
Douglas José Faria ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Lignocellulosic Biomass ◽  
Value Added ◽  
Renewable Sources ◽  
Renewable Source ◽  
Different Types ◽  
Historic Background ◽  
Made In ◽  
Value Added Products

Lignocellulosic biomass has been widely investigated as a natural renewable source of feedstocks to produce high value added products which can replace energy and materials obtained from non-renewable sources. Polymers are products largely employed in industry in many different applications, which nowadays are mostly produced from petrochemical derivatives, generating huge amounts of waste of difficult treatment prior to disposal. In order to replace these polymers derived from petroleum, efforts have been made in the development of biopolymers, in the biorefinery context, derived from biomass possessing physicochemical properties similar to those derived from petroleum so that they can successfully replace these materials. A review on the different types of biopolymers obtained from biomass, as polysaccharides, lipids, proteins, polyesters produced by plants and microorganisms, and other assorted biopolymers is accomplished. An evaluation of physicochemical properties and applications of different types of biopolymers is approached. It is also discussed about the degradability of biopolymers differentiating oxo-degradability and biodegradability. A brief historic background about biopolymers is also exposed.

scholarly journals Elucidation of the Roles of Ionic Liquid in CO2 Electrochemical Reduction to Value-Added Chemicals and Fuels

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6962
Author(s):  
Sulafa Abdalmageed Saadaldeen Mohammed ◽  
Wan Zaireen Nisa Yahya ◽  
Mohamad Azmi Bustam ◽  
Md Golam Kibria
Keyword(s):  
Carbon Dioxide ◽  
Ionic Liquids ◽  
Reaction Mechanism ◽  
Electrochemical Reduction ◽  
Value Added ◽  
Faradaic Efficiency ◽  
Renewable Source ◽  
Carbon Dioxide Co2 ◽  
Physical And Chemical ◽  
Value Added Products

The electrochemical reduction of carbon dioxide (CO2ER) is amongst one the most promising technologies to reduce greenhouse gas emissions since carbon dioxide (CO2) can be converted to value-added products. Moreover, the possibility of using a renewable source of energy makes this process environmentally compelling. CO2ER in ionic liquids (ILs) has recently attracted attention due to its unique properties in reducing overpotential and raising faradaic efficiency. The current literature on CO2ER mainly reports on the effect of structures, physical and chemical interactions, acidity, and the electrode–electrolyte interface region on the reaction mechanism. However, in this work, new insights are presented for the CO2ER reaction mechanism that are based on the molecular interactions of the ILs and their physicochemical properties. This new insight will open possibilities for the utilization of new types of ionic liquids. Additionally, the roles of anions, cations, and the electrodes in the CO2ER reactions are also reviewed.

Olive-derived biomass as a renewable source of value-added products

2020 ◽  
Vol 97 ◽  
pp. 43-56 ◽  
Author(s):  
María del Mar Contreras ◽  
Inmaculada Romero ◽  
Manuel Moya ◽  
Eulogio Castro
Keyword(s):  
Value Added ◽  
Renewable Source ◽  
Value Added Products

scholarly journals Structural Application of Lightweight Panels Made of Waste Cardboard and Beech Veneer

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5064
Author(s):  
Vassil Jivkov ◽  
Ralitsa Simeonova ◽  
Petar Antov ◽  
Assia Marinova ◽  
Boryana Petrova ◽  
...  
Keyword(s):  
Bending Strength ◽  
Urea Formaldehyde ◽  
Value Added ◽  
Bending Moments ◽  
Furniture Design ◽  
Stiffness Coefficients ◽  
Uf Resin ◽  
Corrugated Cardboard ◽  
Strength And Stiffness ◽  
Value Added Products

In recent years, the furniture design trends include ensuring ergonomic standards, development of new environmentally friendly materials, optimised use of natural resources, and sustainably increased conversion of waste into value-added products. The circular economy principles require the reuse, recycling or upcycling of materials. The potential of reusing waste corrugated cardboard to produce new lightweight boards suitable for furniture and interior applications was investigated in this work. Two types of multi-layered panels were manufactured in the laboratory from corrugated cardboard and beech veneer, bonded with urea-formaldehyde (UF) resin. Seven types of end corner joints of the created lightweight furniture panels and three conventional honeycomb panels were tested. Bending moments and stiffness coefficients in the compression test were evaluated. The bending strength values of the joints made of waste cardboard and beech veneer exhibited the required strength for application in furniture constructions or as interior elements. The joints made of multi-layer panels with a thickness of 51 mm, joined by dowels, demonstrated the highest bending strength and stiffness values (33.22 N∙m). The joints made of 21 mm thick multi-layer panels and connected with Confirmat had satisfactory bending strength values (10.53 N∙m) and Minifix had the lowest strength values (6.15 N∙m). The highest stiffness values (327 N∙m/rad) were determined for the 50 mm thick cardboard honeycomb panels connected by plastic corner connector and special screw Varianta, and the lowest values for the joints made of 21 mm thick multi-layer panels connected by Confirmat (40 N∙m/rad) and Minifix (43 N∙m/rad), respectively. The application of waste corrugated cardboard as a structural material for furniture and interiors can be improved by further investigations.

LIGNIN FROM STEAM‐EXPLODED WOOD AS BINDER IN WOOD COMPOSITES

2010 ◽  
Vol 18 (2) ◽  
pp. 75-84 ◽  
Author(s):  
Jānis Grāvītis ◽  
Jānis Āboliņš ◽  
Ramunas Tupčiauskas ◽  
Andris Vēveris
Keyword(s):  
Hot Pressing ◽  
Phenol Formaldehyde ◽  
Lignin Content ◽  
Value Added ◽  
Wood Composites ◽  
Factory Production ◽  
Size Of Particles ◽  
Form Stability ◽  
The Eu ◽  
Value Added Products

A study demonstrating the approach of zero‐waste technologies, a component of the Zero Emissions concept, and using lignin extracted from steam‐exploded wood as adhesive in hot‐pressed fibre boards and plywood to substitute phenol‐formaldehyde resins is reported. Properties of sample boards containing different amount of lignin adhesive are compared between themselves and with the EU standards for fibre boards. A strong correlation of density and form stability under humid conditions with the lignin content is found. Results of testing mechanical properties of the boards suggest that effect of lignin on mechanical strength depends on the size of particles and hot‐pressing temperature. Steam explosion and hot‐pressing technologies tested in the study are shown to have potential of utilizing low‐quality wood and waste from forest industry to make value‐added products. Complementing a saw mill they represent a model of integrated technologies cluster in accordance with the concept of Zero Emissions facilitating environmental protection by reducing pollution and eliminating waste. Mixtures of commercial phenol‐formaldehyde resins containing 10% lignin by weight, tested as plywood binders under conditions of factory production, show satisfactory cohesion. Santrauka Ligninas, išgautas garo sprogdinimo būdu, atstoja rišamaja medžiaga medienos plaušo plokštese ir dedamas kaip dalinis pakaitalas i fenolformaldehido klijus, gaminant klijuotaja fanera. Tai beatliekes technologijos pavyzdys igyvendinant bendraja beatliekes gamybos koncepcija. Analizuojamos eksperimentiniu medienos plaušo plokščiu, kurioms naudota skirtingas lignino kiekis, savybes, palyginti su Europos Sajungos standartizuotu medienos plaušo plokščiu savybemis. Nustatyta gera eksperimentiniu plokščiu su lignino priedu tankio ir atsparumo vandeniui koreliacija. Bandymu rezultatai rodo plokščiu stiprio priklausomybe nuo medienos daleliu dydžio ir presavimo temperatūros. Išanalizavus akivaizdu, kad taikant minetaja technologija galima dideles pridetines vertes produktu gamyba iš nekokybiškos medienos ir medienos apdirbimo atlieku. Šiu technologiju taikymas lentpjūvese būtu integruotu technologiju grupes, veikiančios pagal beatliekes gamybos principa, pavyzdys. Bandant klijuotaja fanera, kuria gaminant kaip dalinis pakaitalas fenolformaldehido klijams paruošti naudojamas garo sprogimo procese išgautas ligninas, nustatyta patenkinama kohezija. Резюме Изучено применение лигнина, выделенного из древесной массы после парового взрыва, в качестве связующего компонента в древесноволокнистых плитах и добавки к фенолоформальдегидным клеям для производства многослойных фанер, что является примером безотходных технологических решений в рамках общей концепции безотходного производства. Сравнены свойства образцов плит, полученных горячим прессованием древесной массы с разным содержанием лигнина, и их соответствие техническим требованиям к изделиям. Обнаружена хорошая корреляция плотности и водостойкости плит с содержанием лигнина. Испытания механических свойств полученных образцов свидетельствовали о зависимости прочности от размера древесных частиц и температуры при прессовании. Использованные технологии выявили потенциальные возможности для создания ценных продуктов из низкокачественной древесины и отходов деревообработки. В дополнение к лесопильням они представляют собой образец кластера интегрированных технологий по принципу безотходного производства. Смесь фенолоформальдегидных смол, содержащих 10% лигнина, выделенного из древесной массы после парового взрыва, показывает удовлетворительную адгезию в условиях производства.

scholarly journals Identification and Quantification of Phenolic Compounds from Mexican Oregano (Lippia graveolens HBK) Hydroethanolic Extracts and Evaluation of Its Antioxidant Capacity

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 702
Author(s):  
María del Carmen Cortés-Chitala ◽  
Héctor Flores-Martínez ◽  
Ignacio Orozco-Ávila ◽  
Carolina León-Campos ◽  
Ángela Suárez-Jacobo ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Economic Value ◽  
Biological Significance ◽  
Value Added ◽  
Phytochemical Analysis ◽  
High Concentrations ◽  
First Time ◽  
Value Added Products ◽  
Identification And Quantification

Plants have been used for thousands of years for various purposes because they have a wide variety of activities with biological significance. Mexican oregano is an aromatic plant of great importance to Mexico and north of Jalisco state as a spice with important economic value. Chromatographic identification and quantification of phenolic compounds and evaluation of their antioxidant activity were important tools to obtain a better characterization of this spice. Phytochemical analysis indicated the presence of flavonoids, triterpenes, saponins, quinones and tannins, the latter at high concentrations. Through chromatographic assays of Mexican oregano extracts, 62 compounds were identified, the major ones being quantified as: taxifolin, apigenin 7-O-glucoside, phlorizin, eriodictyol, quercetin, naringenin, hispidulin, pinocembrin, galangin and genkwanin (compound for the first time reported for this species). The results can be useful as a precedent to establish the bases of new quality characterization parameters and they have also suggested that Mexican oregano contains a wide variety of compounds with untapped importance for the development of new high value-added products.

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