Publications by authors named "Lee Seng Hua"

The rising environmental concerns and the growing demand for renewable materials have surged across various industries. In this context, lignin, being a plentiful natural aromatic compound that possesses advantageous functional groups suitable for utilization in biocomposite systems, has gained notable attention as a promising and sustainable alternative to fossil-derived materials. It can be obtained from lignocellulosic biomass through extraction via various techniques, which may cause variability in its thermal, mechanical, and physical properties.

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  • * Key factors affecting adsorption performance included the mass ratio of tannin to chitosan, pH levels, adsorption time, and initial metal ion concentrations, with a maximum adsorption capacity of 37.6 mg/g for Cu and 52.9 mg/g for Pb.
  • * The adsorption process primarily involved single-layer chemical adsorption and demonstrated high removal efficiencies of 82% for Cu and 95% for Pb, with the ability to release the adsorbed ions using a dilute strong acid.
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  • The study investigates coniferous bark as a potential filler for wood-polymer composites (WPCs) and its effects on important properties like strength and water resistance.
  • Six types of bark-PLA composites were created, varied by filler amounts and particle sizes, alongside similar composites made from sawdust for comparison.
  • Results showed that bark-filled composites had better water resistance but lower strength compared to sawdust composites, with filler content being the most significant factor affecting properties.
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In this study, various chitosan-based films such as chitosan (C), chitosan-condensed tannin (CT), chitosan-casein (CC), and chitosan-casein-condensed tannin (CCT) films were prepared for the purpose of food packaging. In order to improve the hydrophobicity of these films, carnauba wax was blended into CCT to produce CCTW film. Properties such as morphology, UV resistance, water solubility, barrier performance, tensile strength, antioxidant, antibacterial and its performance as food packaging were evaluated.

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This study aimed to analyze the effect of pre-heat treatment on bamboo strand properties and its impact on the properties of the resulting bamboo-oriented strand board (BOSB). Giant bamboo ( (Schult.) Backer) with a density of 0.

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This paper investigated the upcycling process of thermoplastic waste polystyrene (WPS) into thermosetting particleboard adhesive using two cross-linkers, namely methylene diphenyl diisocyanate (MDI) and maleic anhydride (MA). The WPS was dissolved in an organic co-solvent. The weight ratio of WPS/co-solvent was 1:9, and 10% of cross-linkers based on the WPS solids content were added subsequently at 60 °C under continuous stirring for 30 min.

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Sepiolite is a silicate mineral that improves the fire properties in solid wood when mixed with a water-based coating. The present study was carried out to investigate and evaluate the effects of sepiolite addition to acrylic-latex paint on the pull-off adhesion strength, as an important characteristic of paints and finishes used in the modern furniture industry and historical furniture as well for preservation and restoration of heritage objects. Sepiolite was added at the rate of 10%, and brushed onto plain-sawn beech (Fagus orientalis L.

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A flame retardant high-performance gelatinized starch (GS)-ammonium dihydrogen phosphate (ADP) wood adhesive, named GS-ADP adhesive was prepared by condensation of GS and ADP under acidic condition. The preparation process of GS-ADP adhesive is very simple by mixing and stirring GS and ADP evenly at room temperature. The results revealed that the GS-ADP adhesive has good storage stability and water resistance, and its wet shear strength is much higher than that of phenolic resin (PF) adhesive.

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The depletion of natural resources and increasing environmental apprehension regarding the reduction of harmful isocyanates employed in manufacturing polyurethanes (PUs) have generated significant attention from both industrial and academic sectors. This attention is focused on advancing bio-based non-isocyanate polyurethane (NIPU) resins as viable and sustainable substitutes, possessing satisfactory properties. This review presents a comprehensive analysis of the progress made in developing bio-based NIPU polymers for wood adhesive applications.

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  • The study explores the use of alternative raw materials, specifically areca-based particleboard, by testing different hardeners and tannin-glyoxal (TG) adhesive formulations to improve adhesion and cohesion properties.
  • Researchers used NHCl and NaOH as hardeners, along with three adhesive formulations at different tannin:glyoxal ratios, and employed various analytical techniques to examine the properties of the adhesive.
  • Results indicated that the highest glyoxal percentage improved polymer bonds, with NHCl hardener yielding superior mechanical properties, and the F1 adhesive formulation demonstrating the best overall adhesion performance, meeting the standards for Type 8 particleboard.
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  • - The demand for cotton in the textile industry is outpacing its supply, leading researchers to explore alternatives like ramie fiber, which is renewable but needs enhanced fire-resistance.
  • - This study examines lignin from black liquor and its use in creating lignin-based non-isocyanate polyurethane (L-NIPU) to impregnate ramie fibers, improving their mechanical properties and weight gain.
  • - Results indicate that longer impregnation times with L-NIPU enhance ramie fiber's properties, but alternative synthesis methods produce less heat resistance than traditional methods, showcasing L-NIPU's potential for broader industrial use.
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  • Nitrocellulose (NC) is derived from lignocellulose materials like cotton and wood pulp and is used in various applications, including biodegradable plastics and propellants, with this study specifically focusing on its production from recycled egg carton pulp.
  • Various nitration durations (40, 50, and 60 minutes) and KOH concentrations (0.6 M, 1.0 M, and 1.5 M) were tested to determine their effects on NC properties, revealing that 50 minutes led to the highest nitrogen content and desirable structural characteristics.
  • The addition of 50-minute nitrated NC as an accelerant in rice husk charcoal briquettes increased the calorific value significantly, demonstrating its potential for improving
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  • This study focused on creating two types of tannin-based resins (tannin-Bio-NIPU and tannin-Bio-PU) to enhance the properties of ramie fibers through an impregnation process.
  • The resins were developed using a reaction involving tannin extract and different chemical components, and the effectiveness of the resins was tested on both treated and untreated ramie fibers.
  • Results showed that the tannin-Bio-PU resin provided better mechanical and thermal properties, particularly with untreated ramie fibers, resulting in increased thermal stability and tensile strength.
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Lignin is a natural biopolymer with a complex three-dimensional network and it is rich in phenol, making it a good candidate for the production of bio-based polyphenol material. This study attempts to characterize the properties of green phenol-formaldehyde (PF) resins produced through phenol substitution by the phenolated lignin (PL) and bio-oil (BO), extracted from oil palm empty fruit bunch black liquor. Mixtures of PF with varied substitution rates of PL and BO were prepared by heating a mixture of phenol-phenol substitute with 30 wt.

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The compatibility between isocyanate and polyol plays an important role in determining a polyurethane product's performance. This study aims to evaluate the effect of varying the ratios between polymeric methylene diphenyl diisocyanate (pMDI) and liquefied wood polyol on the polyurethane film properties. wood sawdust was liquefied in polyethylene glycol/glycerol co-solvent with HSO as a catalyst at 150 °C for 150 min.

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Pull-off strength is an important property of solid wood, influencing the quality of paints and finishes in the modern furniture industry, as well as in historical furniture and for preservation and restoration of heritage objects. The thermal modification and heat treatment of solid wood have been the most used commercial wood modification techniques over the past decades globally. The effects of heat treatment at two mild temperatures (145 and 185 °C) on the pull-off strength of three common solid wood species, i.

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This study aimed to analyze the basic properties (chemical composition and physical and mechanical properties) of belangke bamboo () and its potential as a particleboard reinforcement material, aimed at increasing the mechanical properties of the boards. The chemical composition was determined by Fourier transform near infrared (NIR) analysis and X-ray diffraction (XRD) analysis. The physical and mechanical properties of bamboo were evaluated following the Japanese standard JIS A 5908 (2003) and the ISO 22157:2004 standard, respectively.

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Oil palm trunk (OPT) veneers have the potential to be used in the production of plywood for marine applications. However, OPT is not resistant to fungal decay and termites, limiting its use in the production of marine plywood. As a result, in this study, phenolic resin treatment was used to improve the biological durability of OPT and produce marine grade equivalent (MGE) plywood.

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The purpose of this study was to prepare low-viscosity lignin-based polyurethane (LPU) resins for the modification of ramie ( (L.) Gaudich) fiber via impregnation to improve the fiber's thermal and mechanical properties. Low-viscosity LPU resins were prepared by dissolving lignin in 20% NaOH and then adding polymeric 4,4-methane diphenyl diisocyanate (pMDI, 31% NCO) with a mole ratio of 0.

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The objective of this study was to investigate the production and properties of mixed pellets made from rubberwood ( Muell. Arg) and refuse-derived fuel (RDF) waste with no added binder. Three different conditions of mixed pellets were developed to compare their chemical and physical properties to rubberwood pellets.

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Trypanosoma (Megatrypanum) theileri is a non-pathogenic or weakly pathogenic parasite of domestic cattle that is cyclically transmitted by blood-sucking insects, mainly tabanid flies. It has been reported in several countries like Brazil, Venezuela, Japan, Taiwan, Thailand, Vietnam, and the Philippines. Although the ruminant industry is actively expanded in Malaysia, T.

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The study investigated the effects of the addition of starch on the properties of oil palm biomass particleboard bonded with citric acid. Three kinds of oil palm biomasses were used in this study for the fabrication of particleboard, namely, oil palm frond (OPF), oil palm trunk (OPT), and empty fruit bunch (EFB) particles. Citric acid and tapioca starch at the mixing ratios of 100:0, 87.

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Natural rubber is of significant economic importance owing to its excellent resilience, elasticity, abrasion and impact resistance. Despite that, natural rubber has been identified with some drawbacks such as low modulus and strength and therefore opens up the opportunity for adding a reinforcing agent. Apart from the conventional fillers such as silica, carbon black and lignocellulosic fibers, nanocellulose is also one of the ideal candidates.

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Wood is a versatile material that is used for various purposes due to its good properties, such as its aesthetic properties, acoustic properties, mechanical properties, thermal properties, etc. Its poor dimensional stability and low natural durability are the main obstacles that limit its use in mechanical applications. Therefore, modification is needed to improve these properties.

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In this study, Kraft lignin was esterified with phthalic anhydride and was served as reinforcing filler for poly(butylene succinate) (PBS). Composites with different ratios of PBS, lignin (L), modified lignin (ML) and kenaf core fibers (KCF) were fabricated using a compounding method. The fabricated PBS composites and its counterparts were tested for thermal, physical and mechanical properties.

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