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Molasses can serve as a natural adhesive for plywood and particleboard. However, several disadvantages remain, including lower dimensional stability and low bonding strength compared to other adhesives. Therefore, modifications are needed to use molasses as an adhesive for plywood. This research aims to improve bio-based molasses (MO) adhesive for plywood using citric acid (CA) adhesive. In addition, this research aims to analyze the effect of adding citric acid and to investigate the optimum hot-pressing temperature to produce the best quality plywood. In the first stage, the molasses and citric acid were combined in a ratio of 100:0, 75:25, 50:50, 25:75, 0:100 w/w%. Then, the second stage focuses on analyzing the influences of pressing temperature based on an optimum first stage. The research demonstrated that the addition of CA altered the gelation time, solid content, viscosity, and pH of the molasses adhesives. In addition, the thermal properties of molasses adhesives were changed after mixing with citric acid. These phenomena indicate changes in characteristics, such as the curing of adhesive. Overall, the characteristics of plywood showed a steady improvement as the CA ratio increased but revealed a significant decline for the 25:75 MO-CA ratio. By raising the pressing temperature from 180°C to 200°C, the quality of plywood was effectively improved. The plywood that was bonded using adhesives with a 50:50 MO-CA ratio exhibited superior mechanical properties and improved dimensional stability compared to the plywood bonded solely with MO. Furthermore, the optimal mechanical and physical properties resulted in plywood bonded with a 50:50 MO-CA ratio when subjected to a pressing temperature of 200°C. The Thermal and FTIR measurements revealed that CA established ester bonds with both the MO and wood veneers. In conclusion, the mechanical characteristics of plywood were improved, while maintaining its excellent dimensional stability. [ABSTRACT FROM AUTHOR]

Lignin, lignosulfonate, and synthesized phosphorylated lignosulfonate were introduced as green fillers in citric acid-sucrose adhesives for bonding particleboard fabricated from areca leaf sheath (ALS). The characteristics of particleboards were compared to that of ultralow emitting formaldehyde (ULEF-UF). The fillers derived from Eucalyptus spp. kraft-lignin were added for flame retardancy enhancement. 10% of each lignin and modified lignin was added into the ULEF-UF and citric acid-sucrose bonded particleboards. Analyses applied to particleboards included thermal characteristics, X-ray diffraction analysis (XRD), morphological properties, Fourier transform infrared spectroscopy (FTIR), as well as physical, mechanical, and fire resistance characteristics of the laboratory-fabricated particleboards. Lignin and modified lignin resulted in improved thermal stability of the composites bonded with ULEF-UF while the improvement in the particleboard bonded with citric acid-sucrose was not significant. The introduction of filler exerted a higher influence on the UF-bonded particleboards compared to composites fabricated with citric acid-sucrose. Generally, the presence of lignin, lignosulfonate, and phosphorylated lignosulfonate enhanced the mechanical strength of the ULEF-bonded particleboards, although their dimensional stability has deteriorated. Markedly, the use of lignin and lignosulfonate enhanced the fire resistance of the particleboards produced with lower observed weight loss. All laboratory particleboards exhibited satisfactory fire resistance, attaining a V-0 rating in according to the UL-94 standard. [ABSTRACT FROM AUTHOR]

This study investigates the potential of agricultural by-products, rich in lignocellulosic materials, as sustainable food packaging materials to mitigate the environmental issues associated with nonbiodegradable plastics and styrofoam. Starch-based biodegradable food trays were developed using agricultural by-products, including sorghum stalk, rice straw, and kraft pulp through thermopressing method. By combining varying proportions of polyvinyl alcohol (PVA) and a sorghum-rice straw fiber mixture, biodegradable foam products with notable strength, water resistance, and cost-effectiveness for large-scale production were produced, exhibiting densities between 0.7 and 0.8 gr/m³. Notably, a 5% PVA composition in the sorghum fiber biodegradable foam displayed favourable mechanical properties and water resistance, with a tensile strength of 5 MPa and a contact angle of 73.79°, coupled with an appealing physical appearance. However, increasing PVA concentration beyond this level had negligible effects, indicates the optimal limit of PVA. Additionally, the distinct roles of rice straw powder as a matrix and sorghum fiber as reinforcement within the biodegradable foam were identified. Biodegradation tests revealed natural decomposition starting from the seventh day, with over 95% growth of Aspergillus Niger fungus, suggesting that these biodegradable foam products hold promise for mass production in the packaging industry, presenting a sustainable alternative to conventional plastic packaging.

Emissions of formaldehyde from wood-based panels, such as plywood, are gaining increased attention due to their carcinogenic impact on human health and detrimental effects on the environment. Plywood, which is primarily bound with a urea-formaldehyde adhesive, releases formaldehyde during hot pressing and gradually over time. Therefore, this study aims to analyze the impact of non-formaldehyde adhesive types on plywood performance. In addition, plywood performance was assessed by comparing Jabon wood (Anthocephalus cadamba Miq) veneer with other Indonesian wood veneers such as Mempisang (Alphonse spp.) and Mahogany (Swietenia mahagoni). To manufacture a three-layer plywood panel, a two-step manufacturing process was devised. The first step involved the use of Jabon veneers treated with citric acid (CA), maleic acid (MA), and molasses (MO), and another step was carried out for various wood veneers such as Jabon, Mempisang, and Mahogany using CA. The performance of plywood was examined using JAS 233:2003. The performance of plywood bonded with CA was better than that of plywood bonded with MA and MO. The Jabon wood veneer resulted in a lower density of plywood than other wood veneers. The water absorption, thickness swelling, modulus of elasticity, and tensile shear strength of plywood from Jabon wood veneer were similar to those of plywood from Mahogany wood veneer and lower than those of Mempisang wood veneer. The ester linkages of plywood bonded with CA were greater than those of plywood bonded with MA and MO because plywood bonded with CA has better performance than plywood bonded with MA and MO. [ABSTRACT FROM AUTHOR]

Currently, water-soluble chitosan (WSC) has been developed through a pressurized hydrolysis process. Compared to acid-soluble chitosan, the WSC is soluble in water, and it is used in many applications such as pharmaceutical, food, and composite industries. The FTIR and thermal properties such as TGA were investigated to determine the effect as a sizing agent material on paper composite. Furthermore, the influence of pulp weight variation of 1, 1.5, and 2 g and WSC concentration of 0.25, 0.5, 0.75, and 1.0% (w/v) on the physical, mechanical, and antimicrobial properties of the paper composites were studied. The density and grammage increased after incorporating due to the increase in the dissolved concentration of WSC. The mechanical properties, such as tensile strength, tensile modulus, and elongation at break, were also improved to the highest value of 2.76 MPa, 170.58 MPa, and 2.67% at 1.0% WSC and 1 g pulp concentration, respectively. The paper composite incorporated WSC also showed antimicrobial activity against Gram-positive (Staphylococcus aureus) bacteria and Gram-negative (Escherichia coli). However, increased concentration of WSC up to 1% caused inhibition zone of Gram-negative (Escherichia coli and Salmonella typhi) and Gram-positive (Staphylococcus aureus and Bacillus subtilis) bacteria. [ABSTRACT FROM AUTHOR]

In this study, sucrose and ammonium polyphosphate (APP) were utilized as the raw materials to prepare an environmentally-friendly plywood adhesive. The bonding performance results showed that the optimal synthesis conditions of the sucrose-ammonium polyphosphate (SAPP) adhesive were an 80/20 mass ratio (sucrose/APP) at 115 oC for 3 h, and the optimal manufacturing conditions were 170 oC for 7 min. In addition, the maximum wet shear strength of the obtained three-ply plywood was 0.81 MPa, which satisfied the China National Standard GB/T 9846–2015 (wet shear strength≥0.7 MPa). The insoluble mass proportion was positively associated with the heating temperature and time. The TG and DSC analysis showed that a rapid mass loss of the SAPP adhesive occurred at 143.4 oC, and endothermic peaks appeared at 136.2 and 156.4 oC. The 13C NMR spectra showed that the adhesive contained monosaccharides, oligosaccharides, ketones, HMF, Schiff bases, and various other unknown substances. This implies that hydrolysis, caramelization, and the Amadori rearrangement occurred during synthesis. Furthermore, the FT-IR and Py-GC/MS results indicated that the cured SAPP adhesive was a complex polymer containing furan and nitrogenous compounds, which were connected by dimethylene ether bridges. [ABSTRACT FROM AUTHOR]

This physical and mechanical properties of a table tennis blade made from sorghum bagasse particleboard (TTBSB-particleboard) bonded maleic acid adhesive was investigated under pressing temperature and time variations. The TTBSB-particleboard was produced via a two-stage process in this study. A pressing temperature of 170–200 °C was used to prepare the first stage for 10 min. Following this, the second stage of the TTBSB-particleboard was produced with a different pressing time of 5–20 min. The TTBSB-particleboard had a specified target density of 0.6 g/cm3 and a size of 30 cm × 30 cm × 0.6 cm, respectively. For references concerning the tested quality of TTBSB-particleboard, the JIS A 5908-2003 standard has been used. For comparison, the commercial blades of Yuguan Wooden 1011 and Donic Original Carbo Speed were tested under the same conditions. The quality of the TTBSB-particleboard was successfully enhanced by increasing the pressing temperature (170 to 200 °C) and time (5 to 20 min). As a result, the pressing condition of 200 °C and 20 min were effective in this study. The TTBSB-particleboard in this study has a greater weight than the commercial blades of Yuguan and Donic. However, the TTBSB-particleboard in this study had a ball rebound comparable to that of the Donic blade. [ABSTRACT FROM AUTHOR]

The compatibility of oil-palm-trunk fibers and cement was investigated. Cold-water and hydrothermal carbonization treatments were applied on the fibers, and then the hydration temperature was measured to observe the compatibility. Calcium chloride (CaCl2), as an accelerator, was added at 1.5, 3.0, 4.5 and 6.0% of cement weight. The results showed that cold-water treatment and hydrothermal carbonization of the fibers reduced the hemicelluloses and ash content, thereby increasing the compatibility. Fourier transform infra-red analysis showed that functional groups of untreated and treated fibers were almost identical, indicating that the addition of treated fibers did not interfere the hardening process of cement. The treatment of fibers resulted in reduced thermal stability of the cement-fibers mixture, and the addition of CaCl2 decreased the hydration temperature of the mixtures, indicating that the chemical accelerated the hardening of the cement-fibers mixture. The addition of 1.5% CaCl2 to the cement mixture with treated fibers was adequate to obtain a low inhibitory index. Field emission scanning electron microscopy showed that higher formation of calcium silicate hydrate and calcium carbonate was observed in the treated fibers compared to the untreated fibers. The board modulus of elasticity increased by 215% and 281% after the fibers underwent with cold-water treatment and hydrothermal carbonization, respectively. [ABSTRACT FROM AUTHOR]

The citric acid (CA)-based adhesive, as a new environment-friendly adhesive, has been developed and used for the manufacturing of plywood to resolve the problem of formaldehyde-based adhesive for human health. The effects of pressing time and temperature on physical and mechanical properties of plywood were examined. Three-layer plywood panels were bonded using CA adhesive with a 134 g/m2 of single glue spread on White jabon wood veneer. The plywood panels were hot-pressed at 5 MPa with three different pressing temperatures, 180°C, 190°C, 200°C, for 10 min, and also different pressing times, 4, 7, 10 min at 190°C. The physical and mechanical properties, such as moisture content, delamination, and shear strength, were evaluated according to JAS 233:2003. The results show that the plywood with pressing temperature of 190°C for 10 min had lower delamination and greater tensile shear strength than those of other plywood panels. Moreover, some properties of the plywood fulfilled the requirement of JAS 233:2003. Based on the FTIR analysis, citric acid plays an important role in the formation of ester linkages (R-COO-R) via esterification between carboxyl groups of citric acid and hydroxyl groups of White jabon wood veneer, resulting excellent properties of plywood. [ABSTRACT FROM AUTHOR]

Due to environmental and health concerns, a substitute for conventional wood adhesives has been sought, with bio-based adhesives being one of the most-researched alternatives. Recently, a bio-based adhesive made from citric acid and sucrose was used to manufacture sweet sorghum bagasse particleboard. However, the pressing conditions (200 °C, 10 min) consume a high amount of energy, and so optimization of the pressing condition is required. Therefore, the effects of ZnCl 2 as a catalyst for the curing reaction of citric acid-sucrose adhesive were investigated. Thermal analyses such as differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) as well as Fourier transform-infrared (FT-IR) spectroscopy and insoluble matter analysis were used to investigate the effect of the catalyst on the curing behaviour of a citric acid-sucrose adhesive. DSC and TGA showed that ZnCl 2 decreased the curing temperature, enthalpy reaction, and apparent activation energy. The apparent activation energy obtained using the Kissinger method decreased from 123.7 kJ/mol to 108.7 kJ/mol after 1% ZnCl 2 catalyst was added. The level of insoluble matter in the cured adhesive after 4 h of boiling treatment at 150 °C, 180 °C, and 200 °C with various heating times (6 and 10 min) was higher after the addition of 1% ZnCl 2. FT-IR analysis of the cured adhesive showed that ZnCl 2 could accelerate the thermal degradation of sucrose, the formation of 5-hydroxymethylfurfural, and the formation of polymeric humins. [ABSTRACT FROM AUTHOR]