In this work, the use of furfural, a bio-based platform chemical, was investigated as a sustainable alternative to petrochemical formaldehyde in Phenol Formaldehyde (PF) resins, which are used in the manufacturing of wood-based products such as plywood. The catalytic condensation of phenol with furfural was studied at various temperatures (45-135(o)C) to determine the reactivity of furfural towards formation of the respective dimers and oligomers. A pretreatment was applied to partially convert furfural to furfuryl alcohol which facilitated the condensation of phenol with furfural, at temperatures >90(o)C. PF-Furfural (PFFu) resins were prepared at semi-pilot scale (2-3 Kg) following typical industrial protocols aiming at the gradual replacement (20-80 wt%) of formaldehyde. The properties of the PFFu resins were characterized by various methods (solids, pH, viscosity etc.) and C-13 NMR analysis. The PFFu resins with up to 60 wt% replacement of formaldehyde by furfural exhibited typical properties for such PF-type resins; however, viscosity and gel time were gradually decreased and increased, respectively, indicating the relatively reduced reactivity of furfural at the applied synthesis conditions (i.e. 90-100(o)C) compared to formaldehyde. Plywood panels prepared with PFFu resins, demonstrated enhanced mechanical performance compared to the reference PF resin - such as improved shear strength (>1.5 N/mm(2)) and wood failure (>= 85 %) thereby meeting the requirements of the European standard EN314-2:1993. Furthermore, all panels prepared with furfural-containing resins exhibited significantly lower free formaldehyde emission (0.01-0.18 mg/m(2)h) compared to the reference panels (0.20 mg/m(2)h). The results highlight the possibility of formaldehyde replacement by furfural in the production of sustainable plywood products.

Particleboards were developed by replacing a part of wood with various biomass residues, including coffee bean husks, spent coffee grounds, thistle, Sideritis and dead leaves of Posidonia oceanica. These materials were analysed to determine their physicochemical properties like the moisture content, pH, and buffer capacity, using standard laboratory techniques, while thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) were also used for their further characterisation. The results revealed that all biomasses contained cellulose, hemicellulose, and lignin in varying proportions, along with differing degrees of crystallinity. To produce particleboards, the biomasses were bonded using two types of adhesives: (a) conventional urea-formaldehyde resin (UF) and (b) polymeric 4,4′-methylene diphenyl isocyanate (pMDI). Laboratory-scale, single-layer particleboards were manufactured simulating industrial production practices. These panels were evaluated for their mechanical and physical properties according to European standards. The findings showed a general reduction in mechanical performance when compared to conventional wood-based panels. However, panels made with coffee grounds and Posidonia showed improved resistance to thickness swelling after 24 h in water at 20 °C. Additionally, all experimental panels exhibited lower formaldehyde content than wood-based reference panels. This study demonstrated the feasibility of upcycling biomass residues as a sustainable alternative to virgin wood in the production of particleboard, providing a resource-efficient solution for specific interior applications within a circular economy framework.

This research addresses the current need for sustainable solutions in the construction and furniture industries, with a focus on environmentally friendly particleboard. Particleboards were made from a mixture of virgin wood chips and hemp shives, which were then mechanically recycled and used to make new lightweight particleboards. Phenol–formaldehyde resin with 25% w/w phenol replacement by soybean flour (PFS) was used as the binder for the lignocellulosic materials. Laboratory analyses determined the resin properties, and FTIR confirmed the structure of the experimental PFS resin. The thermal properties of all the resins were evaluated using thermogravimetric analysis (TGA). The panels were manufactured using industrial simulation and tested for mechanical and physical properties in accordance with European standards. The FTIR study confirmed good adhesion, and the TGA showed improved thermal stability for the recycled biomass panels compared to virgin biomass panels. The study concludes that lightweight particleboards can be successfully produced from recycled hemp shive-based panels, providing a sustainable alternative to traditional materials in the construction industry.

This study investigated the use of non-formaldehyde binders in the production of plywood panels, focusing on mixtures containing 70% poly 4,4’-methylene diphenyl isocyanate (pMDI) and 30% soy flour (SF), along with blends of soy flour and agricultural residues (olive by-products—with and without extraction of their bioactive ingredients—and defatted hemp seeds). The basic properties of these biomaterials, such as moisture content, pH, and buffering capacity, were determined with laboratory analysis. Adhesive mixtures were characterized using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and thermogravimetric analysis (TGA). The adhesive’s bonding ability was evaluated by manufacturing plywood panels on a laboratory scale, simulating industrial practices. The glue lines were visually inspected with a stereomicroscope. Micro-ATR-FTIR study of the cross-sections of plywood panels showed the full consumption of isocyanate groups indicating effective curing of the adhesive. Mixtures containing olive residues, particularly olive skin and stones, showed improved thermal stability in the TGA study. The mechanical properties of the plywood panels were assessed with three-point bending tests, while their shear strength and wood failure performance were tested according to the European standards used in the relevant industry (EN 314.1:2004 and EN 314.2:1993). In terms of flexural properties, the adhesive with non-extracted (NE) residual olive skin (ROS) showed the highest flexural strength of around 17 MPa and a flexural modulus of 650 MPa. The formulations containing extracted materials from hemp seeds (HSs) and residual olive skin (ROS) showed the best overall performance with wood failure values of 85% and 75% after the most severe cyclic test (EN314.1:2004-Pretreatment 5.1.3). Overall, the results showed that binders prepared with residual olive skin and defatted hemp seeds have promising performance and can be used in the manufacture of plywood panels.

In achieving the European Union's goal of making Europe the first climate-neutral continent by 2050, the scientific community is striving to develop processes and products that are technologically and economically sustainable to replace/substitute fossil-based feedstocks. In this effort, the European project LIBERATE has demonstrated the commercial opportunities of converting low-cost lignin feedstocks into high-value bio sustainable chemicals such as vanillin and mixed phenolic derivatives. Lignin is the largest regenerative source of aromatic organics. In current wood pulping industries, lignin is underutilized and widely considered a side stream primarily exploited for its energy content. A promising approach for the synthesis of biobased fine chemicals is a depolymerisation process for lignin using sodium peroxodicarbonate (PODIC®), an electrochemically produced oxidiser. Within the LIBERATE project, SINTEF has built a pilot scale plant for the electrochemical lignin depolymerisation. The plant provided CHIMAR with the phenol-rich reactor product solution from both kraft and organosolv lignin, which was used as phenol substitutes with up to 50 wt% in the formulation of phenol-formaldehyde (PF) resins. These resins have been able to produce successful plywood panels on a laboratory scale. Although their quality is somewhat lower than that of the reference material with traditional PF resin, this work showed that the use of lignin fractions obtained by electrochemical treatment in such an application is possible and promising.

The present study focuses on the interaction of recently synthesized unsaturated polyester resins (UPRs) with wood. The UPRs are prepared from succinic acid, maleic anhydrite, and ethylene glycol or poly(ethylene glycol) as biobased monomers and crosslinked with acrylic acid. In this framework, small 3-ply composite specimens (0.1 x 2.5 x 10 cm) of wood veneers are prepared with such binders to investigate their interaction with wood. The produced experimental specimens are studied with Fourier transform infrared spectroscopy, thermogravimetry, and scanning electron microscopy to explore their morphological and thermal degradation characteristics, as well any chemical changes from the interaction of the UPRs with wood. The experimental results indicate no chemical changes from their interaction with wood.

Toxic formaldehyde emissions, and the necessity to reduce the consumption of petrochemicals, stimulates the development of environmentally friendly adhesives. The aim of this research was to study, for the first time, the possibility of using condensed tannins (CTs)-rich extracts from grey alder (Alnus incana) and black alder (Alnus glutinosa) bark in the production of particleboards and plywood adhesives. The chemical structure, composition, and molecular weight of the CTs were identified by a 13C-NMR and TOF-MS analysis. Three innovative adhesive systems were studied: CTs-phenol-formaldehyde (CTs-PF) resin; a CTs-polyethyleneimine (PEI) adhesive system; and CTs–PEI combined with an ultra-low emitting formaldehyde resin (ULEFR)—CTs–PEI–ULEFR. The results showed that CTs-PF resin has properties close to commercial PF resin, and the formaldehyde emission was twice lower. CTs–PEI bonded particleboards corresponded to the requirements of the EN 312:2010 standard for particleboards in dry conditions (Type P2). CTs–PEI–ULEFR, with a 40–60% substitution of ULEFR by CTs–PEI, had adhesive properties very close to ULEFR; the plywood shear strength fit the requirements of the EN 314-2:1993 standard for application in internal and external system conditions. The introduction of extracted alder bark residues microparticles into the composition of the adhesive system showed their positive potential for application as a filler.

Polymers from renewable feedstocks are receiving increasing attention as the awareness about environmental issues derived from petroleum exploitation and waste accumulation is growing. With unsaturated polyester resins being one of the most used classes of polymers worldwide, the utilization of biobased monomers for manufacturing is more relevant than ever. In the present work, succinic acid, one of the most promising biobased building blocks, was incorporated in the structure of the resins in question to increase their biobased content. By reacting with ethylene glycol (EG) or poly(ethylene glycol) and maleic anhydride (MA) at several molar rations, unsaturated polyester resins (UPRs) were prepared. Their synthesis was evaluated by a variety of spectroscopical techniques, and their rheological properties made use of the reactive diluent mandatory for facilitating processing. Thus, in a second stage acrylic acid (AA) was used as cross-linking agent in the present of initiators and accelerators producing thermosetting resins. Differential scanning calorimetry (DSC) was employed to screen the cross-linking procedure, whereas with X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) it was proven that thermosetting resins were prepared. The thermal stability of the cured materials was evaluated by thermogravimetric analysis (TGA).

Phenol-formaldehyde (PF) resins are widely used in wood-based applications by reason of their heat and water resistance, high mechanical strength and chemical stability. Challenges regarding the environmental impact of petroleum-based resources lead to an increased interest of developing new resins where components such as phenol are replaced with renewable materials. This work evaluates the environmental impact of phenol-formaldehyde resins using an organosolv lignin as phenol replacement. Two life cycle analysis (LCA) boundaries (i.e. Cradle-to-Gate, Gate-to-Gate) are studied for PF resin having different substitution levels of phenol: 0%, 40% and 100%. The LC Soft (ICAS) is used for the LCA, which provides information regarding the carbon footprint (CF), fifteen environmental impact categories (e.g.: soil, water, air, human toxicity) and the life cycle inventory (LCI) contribution. The results show improvements for all environmental impact categories for the lignin substituted resins compared to PF resin, confirming the significant role of lignin. Moreover, the impact of the raw materials (Cradle-to-Gate) is significantly higher than the impact of the production process (Gate-to-Gate).

The population growth and the limited reservoir of fossil resources have ignited the attention of scientific communities and entrepreneurs to produce alternative products with raw-materials from renewable sources. In this work, proteins derived from the recycling of waste textiles were studied as raw-material in the synthesis of thermosetting polymers of a phenolic type suitable for use as adhesives in the production of wood-based panels. The chemical bonds between raw-materials and phenol-formaldehyde (PF) resins were verified with Fourier Transform Infrared spectroscopy. The curing performance and thermal stability of the thermosetting PF resins were studied with Differential Scanning Calorimetry and Thermogravimetric Analysis, respectively. Wood-based panels were prepared and tested at a lab scale following simulation of the industrial practice. Optical Microscope and Scanning Electron Microscopy were applied for the study of the interaction between PF resins and woodchips at the lab scale. It was found that the resins were successfully prepared. The maximum curing temperature of the experimental resins was shifted to higher values than the control PF. The protein-based resins seem to lose mass at a lower rate, which denotes that they are more thermally stable than a typical PF resin.

Economic activity that takes environmental protection into account and uses the environmental benefits of an area or country may continuously combine growth with sustainability thereby providing prosperity and societal quality. This paper aims to complement European research on Bioeconomy by reviewing current situation and future trends in Greece. Current data testify that there are significant opportunities for Greece to progress towards a lucrative economy based on renewable resources. The effective growth of such Bioeconomy in Greece depends on the successful cooperation of all stakeholders (state, business, citizens). This is the first study that provides a numerical analysis of the Bio-economy opportunities for Greece and may constitute the foundation for future research, suggestions for policy measures and strategic planning.

The last decades, investigators have been striving to find alternatives to materials and products from fossil sources in response to the need to get independent from petroleum. So far, the most attractive renewable source has been found to be biomass and especially wood that is easily accessible and offers a wide range of building blocks with diverse chemistries and structures that can then be used to build materials for the modern world. In this study, wood from Aspen, Pine and Birch as well as a mixture of Spruce and Pine was subjected to torrefaction and the fraction of the condensables with a dew point above 140 degrees C was used for the partial replacement of phenol (up to 40% wt) in the synthesis of resol phenol-formaldehyde resins suitable to be used as adhesives in the manufacturing of plywood panels. The condensables and the resins were subjected to typical lab analysis and thermal study with TGA and DSC while the plywood panels were tested and evaluated according to the European standards used by the relative industry. It was found that the studied torrefaction condensables may be successfully used in this application while the one from pine was the best performed overall.

Scientists today are intensively seeking alternatives to petrochemical materials. Among others, lignin is a promising candidate because it is available in large quantities while its chemical structure makes its use possible in a variety of chemical reactions. Lignin, received by numerous methods from various feedstocks, is a promising material for the synthesis of many products like active carbon, thermosetting and thermoplastic polymers, surfactants, phenolic chemicals, etc. In this paper, the potential of using Biolignin – a trademarked organosolv lignin from straw prepared by Compagnie Industrielle de la Matière Végétale (CIMV; Neuilly-sur-Seine, France) – in the synthesis of phenol-formaldehyde (PF) resins was studied by CHIMAR HELLAS S.A. (Kalamaria, Greece). Before its use, Biolignin was further purified and subjected to mechanical treatment for the reduction of its particle size in order to increase its reactivity. The effectiveness of the treatment was verified by atomic force microscopy (AFM) measurements that were carried out by SYNPO Company (Pardubice, Czech Republic). Resol phenolic resins were prepared with various substitution levels of phenol up to 80%. However, their synthesis process was smooth only up to the substitution level of 50%. The properties of the resins were determined with typical lab analysis. Their thermal behavior was studied with differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) measurements that were conducted by the Aristotle University of Thessaloniki in Greece. Their bonding ability was evaluated by CHIMAR HELLAS via their application in the production of plywood panels of three layers that were prepared following a simulation of the industrial process. The panels were tested for their properties according to the relevant European standards, while their performance relative to fire was studied with cone calorimetry measurements that were performed by the Latvian State Institute of Wood Chemistry (LIWC; Riga, Latvia). All results were compared with that of a typical PF resin. It was found that the particle size of lignin affects the performance of the resins, while lignin-based PF resins are suitable for the production of plywood panels and have somewhat better performance relative to fire than typical PF resins. This study has been performed within the framework of the European project BIOCORE (biocommodity refinery for biofuels, chemical intermediates, polymers and materials).

Conventional composites from wood and synthetic polymers, like particleboards, find many applications in the construction and furniture sector. However, deforestation, global warming, the concern about adequate wood supplies in the long term, countries that have no land suitable for the development of forests, high volumes of unused agricultural wastes, accumulation of nondegradable plastics, and the unceasing interest of the consumers for new products, are some of the reasons that motivate scientists to seek alternative solutions to wood and petrochemical polymers. The most feasible solution so far seems to be the manufacturing of particleboards with materials from renewable resources that are also biodegradable. To this direction, various agricultural wastes, mostly from lignocellulosic crops like hemp, kenaf, jute, etc., but also residues from other cultivations like rye, rice, wheat, as well as grasses, have been successfully used in combination with biodegradable polymers from natural resources like starch, proteins, PLA, etc. for the production of panels like particleboards. Such panels may be used in a plethora of indoor applications like veneer substrates, flooring, cupboards, furniture, and many others. The demand for both particleboards and biodegradable polymers are expected to increase significantly in the forthcoming years and their future market outlook is very promising.

The objective of this work was the development of environmentally-friendly, sustainable adhesive systems for the manufacture of engineered wood products (mainly glulam) to replace synthetic adhesives made from petrochemicals. Lignin-based adhesive systems were proven to provide industrial glulam products with performance comparable to the products produced with conventional gluing systems. The application of this innovative adhesives technology is expected to provide environmental and cost benefits and to lead to higher demand for glulam products when carbon neutral building solutions are sought.

The aqueous phase resulting from the catalytic pyrolysis (AQcatPy) of biomass has been successfully applied for acidification of urea-formaldehyde (UF) resins. The resins were synthesized at a laboratory scale and characterized by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The bonding ability of the resins was tested through the preparation of particle boards (PBs). It was found that the UF resins prepared with AQcatPy as acidification medium have a similar performance to typical UF resins, where conventional chemicals like formic acid (FA) or acetic acid (AA) serve for pH adjustments. The new resins give PBs with somewhat improved thickness swelling (TS) values, while all other properties are at the same level.

Responding to the market trends, CHIMAR HELLAS S.A., a Greek SME company serving the wood-based panels' industry, has developed resins and impregnation syrups that offer improved water and oil repellency properties to wood-based panels. For this achievement, CHIMAR HELLAS S.A., has been cooperated with the pioneering nanotechnology company NanoPhos S.A., located in Lavrio, Greece. NanoPhos developed nanomaterials tailor made for CHIMAR products, while CHIMAR modified the synthesis process of its resins and syrups in order to fit with the special properties of the NanoPhos products. CHIMAR has used the nanomaterials as additives in the glue mixture of Urea-Formaldehyde (UF) resin suitable for the manufacturing of particleboards, as covering materials of particleboards and as additives in Melamine Formaldehyde (MF) impregnation syrups for lamination papers. Tests have been carried out both at lab and industrial scale and the results show that the nanoadditive enhanced CHIMAR products can offer wood-based panels with improved oil and water repellency surfaces. Such products, with new attractive and easy care properties, are expected to find high appreciation in the market.

In the present work, the effective use of polyethylene-grafted maleic anhydride (PE-g-MA) copolymer as a compatibilizer in high-density polyethylene composites containing 10–50 mass% hemp fibers was evaluated through mechanical and thermal properties measurements. The results revealed a significant reinforcement on the tensile strength of the composites as a consequence of the incorporation of the compatibilizer. Less pronounced effects were found on the elongation at break and impact strength of the composites. The notable enhancement of tensile strength on the compatibilized composites was related to the improved adhesion of hemp with the matrix in the presence of PE-g-MA, which was revealed through scanning electron microscopy observations. Furthermore, Fourier transform infrared spectroscopy analyses suggested that covalent bonding occurs between the fibers and the matrix in the highest PE-g-MA concentrations. Differential scanning calorimetry experiments revealed that the presence of compatibilizer increases the crystallinity of the composites. Thermogravimetry studies revealed that for low compatibilizer concentrations the thermal stability of the composites is further reduced, while for the highest concentration, when bonding occurs, it is enhanced. The biodegradation studies of all the composites revealed that the incorporation of compatibilizer enhances the stability of the composites, especially in the higher concentrations, and reduces their final residue.

To increase the share of biomass for renewable energy in Europe conversion pathways which are economic, flexible in feedstock and energy efficient are needed. The BioBoost project concentrates on dry and wet residual biomass and wastes as feedstock for de-central conversion by fast pyrolysis, catalytic pyrolysis and hydrothermal carbonization to the intermediate energy carriers oil, coal or slurry. Based on straw the energy density increases from 2 to 20-31 GJ/m3, enabling central GW scale gasification plants for bio-fuel production. The catalytic pyrolysis reduces oxygenates in the oil enabling power and refinery applications. The fast pyrolysis and HTC processes of demo-size are optimized for feedstock flexibility, yield, quality and further up-scaling is studied. A logistic model for feedstock supply and connection of de-central with central conversion is set up and validated allowing the determination of costs, the number and location of de-central and central sites. Techno/economic and environmental assessment of the value chain supports the optimization of products and processes.