Properties And Decay Resistance Of Mahang (Macaranga Sp.) Treated With Phenolic Resin And Acrylic Monomer Using Vacuum-Pressure Process

Mahang (Macaranga sp.) was treated with phenolic resin and methyl methacrylate (MMA) monomer. Impreg is a type resin treated wood while Compreg refers to resin treated compressed wood. Mahang wood was impregnated with 15, 20 and 25% (Impreg) and 15% (Compreg) phenolic resin using vacuum-pressure process. The vacuum-pressure process could maximize the penetration of resin and monomer into wood. The resin in Impreg mahang was partially cured at 65ºC for 24 h prior to fully cure at 150ºC for 30 min in an oven while Compreg mahang was fabricated by compressed the treated wood with 0.3, 0.4 and 0.5 compression ratios (CR). The resin in treated wood was partially cured at 65ºC for 56 h prior to fully cure at 150ºC for 30 min under hot press. For MMA-treated wood, polymerization was carried out in a combination with a crosslinker trimethylolpropane trimethacrylate (TMPTMA). Polymerization was carried out by catalyst heat treatment at 65 ºC for 2 h. The resin weight percent gain (WPG) for Impreg mahang was in the range of 33-51% whereas for Compreg mahang was 27-31%. For MMA-treated wood, a fairly consistent acrylic retention ranged from 187.5-229.6% was found in the wood when treated with or without crosslinker. The resin WPG of Impreg mahang was increased significantly when the levels of phenolic resin increased from 15-25%. The resin WPG for Compreg mahang was not differed significantly among 0.3, 0.4 and 0.5 CRs. It was found that the concentrations of crosslinker gave significant effect on the polymerization of MMA. The polymerization is at maximum with 1% crosslinker and beyond this concentration the polymerisation decreased. The density of Impreg, Compreg and MMA-treated mahang was improved significantly from 31-53%, 89-139% and 188-216%, respectively compared to untreated wood. The Impreg and MMA-treated mahang showed improvement in the dimensional stability compared to untreated wood but there is no improvement was recorded for Compreg mahang. The phenolic resin concentrations did not gave significant effect in the ASE of Impreg and Compreg mahang while the crosslinker concentrations gave significant effect in the ASE of MMA-treated mahang. Mositure excluding efficiency (MEE) of Impreg, Compreg and MMA-treated mahang was also improved significantly from 6.27-9.63%, 15.48- 27.85% and 40.93-55.68%, respectively compared to untreated wood. The phenolic resin and crosslinker concentrations did not gave significant effect in the MEE. The improvement in reduction in water absorption (R) of Impreg, Compreg and MMA-treated mahang against untreated wood was ranged from 49.02-65.04%, 67.54-71.63% and 91.18-93.22%, respectively. The phenolic resin and crosslinker concentrations did not gave significant effect in the (R) except for Impreg mahang. Mechanical strength of Impreg mahang in terms of compressive stress and hardness were improved 75 to 266% and 32 to 62%, respectively compared to untreated wood. The compressive stress and hardness of MMA-treated mahang were 577 to 1387% and 219 to 386% greater than untreated wood. However, the stiffness (modulus of elasticity) did not change.All the mechanical properties for Compreg mahang were improved significantly compared to untreated wood. In terms of specific strength (strength to density ratio), the treated material has less stiffness and less strength in lateral direction compared to untreated wood. However, the specific compressive strength perpendicular to the grain and hardness of the treated material were superior compared with the untreated. The decay resistance of Impreg, Compreg and MMA-treated mahang against white rot fungus, Pycnoporus sanguineus was improved significantly compared to untreated wood

Possibility of enhancing the dimensional stability of jelutong (Dyera costulata) wood using glyoxalated alkali lignin-phenolic resin as bulking agent

The utilization of low molecular weight phenol formaldehyde (LmwPF) resin as bulking agent to enhance the dimensional stability of wood brought some disadvantages, such as phenol is derived from non-renewable petrochemicals while formaldehyde is a known carcinogen. Hence, the possibility of using bulking agent made of glyoxalated alkali lignin (GL) incorporated in LmwPF resin to enhance the dimensional stability of wood was investigated. FT-IR spectroscopy showed that polymerization of GL and LmwPF resin was accomplished via the formation of methyl ether (CH2OCH2) bridge. Small amount of crosslinked polymer network was accomplished via the formation of methylene (CH2) bridge. Oven dried jelutong wood was evacuated under vacuum followed by soaking in 15, 20 and 25% concentrations of glyoxalated alkali lignin-low molecular weight phenol formaldehyde (GL-LmwPF) (67% solid of GL: 33% solid of LmwPF based on the total solute content) and LmwPF resins, respectively at ambient temperature for 24 h. The impregnated wood was then cured at 190 °C for 30 min. The weight percent gain (WPG) and dimensional stability in terms of antiswelling efficiency (ASE), moisture excluding efficiency (MEE) and water absorption (WA) as well as leachability of bulking agents were determined and compared with untreated wood and wood treated solely with LmwPF resin. The WPG of GL-LmwPF treated wood was lower than LmwPF treated wood. GL-LmwPF treated wood exhibited positive ASE, but the values were lower compared to LmwPF treated wood. The MEE and WA of GL-LmwPF treated wood were also inferior to LmwPF treated wood and untreated wood. GL-LmwPF resin was leached out from the treated wood whereas no leaching was found for LmwPF treated wood after three leaching cycles in distilled water. The formaldehyde release of GL-LmwPF resin treated wood was 25.76% less than of wood treated with LmwPF resin. Wood treated with 25% GL-LmwPF resin yielded highest ASE value compared to 15 and 20% GL-LmwPF treated wood. Hence, wood treated with 25% GL-LmwPF resin together with external coatings could be used in several end applications such as parquet flooring, paneling and furniture component

Enhancing the Properties of Mahang (Macaranga spp.) Wood through Acrylic Treatment in Combination with Crosslinker

Macaranga spp. (mahang) was treated with methyl methacrylate (MMA) in combination with a crosslinker trimethylolpropane trimethacrylate (TMPTMA). Polymerisation was carried out by catalyst heat treatment. A fairly consistent acrylic retention was found in the wood when treated with or without crosslinker. Polymerisation of MMA is at maximum with 1% crosslinker and beyond this concentration the polymerisation decreased. The dimensional stability in terms of anti-swelling efficiency (ASE) was determined and found to be improved on treatment. Water absorption was also found to be decreased considerably for treated wood. Mechanical strength of the treated wood in terms of modulus of rupture (MOR), compressive stress and hardness were improved, but the stiffness (modulus of elasticity) did not change. In terms of specific strength (strength to density ratio), the treated material is less stiffer and less strength in lateral direction compared to untreated wood. However, the specific compressive strength perpendicular to the grain and hardness of the treated material were superior compared with the untreated

Dimensional stability of heat oil-cured particleboard made with oil palm trunk and rubberwood

Dimensional stability of heat oil-cured particleboard made with admixture of oil palm trunk and rubberwood was evaluated. Particleboard made with oil palm trunk had better dimensional stability due to better compact ratio and lower hygroscopicity than rubberwood. Combination of repellent properties of oil and application of heat had greatly reduced the hygroscopicity of particleboard by decreasing its equilibrium moisture content, thickness swelling and water absorption

Possibility of improving the properties of Mahang wood (Macaranga sp.) through phenolic compreg technique

Lesser known wood species (LKS) have the potentials to become an alternative sources of timber supply for wood based industries if their properties can be improved. In this study, Mahang wood (Macaranga sp.) was impregnated 15% (w/v) low molecular weight phenol formaldehyde (LMWPF) followed by compressing in a hot press at 70, 60 and 50% compression ratios (CR). The treated wood was partially dried in an oven at 65°C until 10% moisture content and subsequently followed by curing at 150°C for 30 min in a hot press. The results showed that the phenolic compreg technique had successfully increased the dimensional stability and mechanical properties of the wood. The polymer retention calculated based on weight gain regardless of compression ratio was approximately 30%. The majority of the properties were improved by the degree of compression in a hot press. Nevertheless, thickness swelling and swelling coefficient increased which were due to spring back effect. As regards to specific strength (strength to density ratio), the compreg wood displayed lower strength and stiffness in lateral direction compared with untreated solid wood. However, the specific compressive strength perpendicular to grain and hardness of the compreg wood were superior than untreated solid wood. The treatment had also changed the wood into highly resistant to fungal decay

Lignin-based copolymer adhesives for composite wood panels – a review

Lignin is a natural and renewable organic compound that can be easily obtained from spent pulping liquors. It can be used as feedstock for making wood adhesives. Nonetheless, lignins need to be modified to enhance reactivity prior to being used as feedstock for making wood adhesives. Appropriate crosslinkers are also needed to ensure the bonding quality of the lignin-based wood adhesives. In the present review, the drawbacks of using lignins alone as wood adhesives, modifications to enhance the reactivity of lignins and production of lignin-based copolymer adhesives for composite wood panels are reviewed and discussed. The objective of this review is to provide background information about the recent status on the development of lignin-based copolymer adhesives for the production of composite wood panels as well as the future prospects of these adhesives in industry. Several modifications such as demethylation, oxidation, methylolation, phenolation, reduction and hydrolysis have shown promising results for enhancing the reactivity of lignins. Several crosslinkers such as phenolic resin, tannin, polymethylene polyphenyl isocyanate (pMDI), furfural and ethylenimine are capable of copolymerizing with lignins to produce lignin-based wood adhesives. The performance of composite wood panels bonded with modified lignin-based copolymer adhesives have been shown to meet the requirements of relevant standards. The main obstacles for the composite wood panels industry to widely adopt to lignin-based copolymer adhesives are the economic and technical issues. Nevertheless, lignin modification methods are proving to enhance the reactivity of lignins and the optimization in such modification methods would justify the economic issue. Together with the public awareness on the safety, health and environment concerns, the utilization of lignin-based adhesives in the composite wood panels industry is feasible

Thermal treatment of wood using vegetable oils: a review

Wood is an ideal building material as it is renewable and green. However, low dimensional stability and durability might restrict its usage in structural application. Therefore, modification is needed to improve the aforementioned issues. As an environmentally friendly wood modification method, heat treatment of wood using oil as a heating medium has brought to researcher’s attention to the fact that it might serve as an excellent treatment procedure in treating wood. This paper presents a review about the effects of oil heat treatment on the properties of wood such as colour stability, dimensional stability, mechanical strength and durability against termites and fungi as well as its potential to be used as construction and building materials. The pros and cons of using oil as a heating medium in wood treatment are discussed. This review shows discrepancies between the treatment methods or procedures and its resultant findings. Moreover, the effectiveness of the treatment is governed by several factors such as the type of oils used and wood species. The objective of the present paper is to conduct a review of the published literatures regarding the properties of wood modified by oil heat treatment and the results obtained were compared systematically

Thermal treatment of wood using vegetable oils: a review

Wood is an ideal building material as it is renewable and green. However, low dimensional stability and durability might restrict its usage in structural application. Therefore, modification is needed to improve the aforementioned issues. As an environmentally friendly wood modification method, heat treatment of wood using oil as a heating medium has brought to researcher’s attention to the fact that it might serve as an excellent treatment procedure in treating wood. This paper presents a review about the effects of oil heat treatment on the properties of wood such as colour stability, dimensional stability, mechanical strength and durability against termites and fungi as well as its potential to be used as construction and building materials. The pros and cons of using oil as a heating medium in wood treatment are discussed. This review shows discrepancies between the treatment methods or procedures and its resultant findings. Moreover, the effectiveness of the treatment is governed by several factors such as the type of oils used and wood species. The objective of the present paper is to conduct a review of the published literatures regarding the properties of wood modified by oil heat treatment and the results obtained were compared systematically

Effects of two-step post heat-treatment in palm oil on the properties of oil palm trunk particleboard

Chemical, thermal properties, surface characteristics, termite resistance and physico-mechanical properties of urea formaldehyde-bonded oil palm trunk particleboard post heat-treated in palm oil were investigated. Oven dried samples were immersed in palm oil for 24 h prior to expose to temperature of 180, 200 and 220 °C in a laboratory oven for 2 h. Alternation in the chemical composition of treated samples was investigated using Fourier transform infrared spectroscopy (FTIR) analysis. Thermal properties analysis was conducted using Thermogravimetric (TG) and Different scanning calorimetric (DSC) analysis. Surface characteristics were checked using scanning electron microscopy (SEM) while resistance against subterranean termite, Coptotermes curvignathus, was evaluated. Physcial and mechanical properties of the samples was assessed based on antiswelling efficiency (ASE), water repellency efficiency (WRE), bending and internal bonding strength. Degradation of hemicellulose shown in FTIR spectra has contributed to the improvement in dimensional stability. Oil-covered particles as shown in SEM give the particleboard lower water uptake. Treated samples also possess better thermal stability and better resistance against termites as the weight loss caused by termites reduced from 25.6% to 11.0%. Generally, improvement in dimensional stability accompanied by severe reduction in mechanical strength were recorded in the treated samples

Effects of two-step post heat-treatment in palm oil on the properties of oil palm trunk particleboard

Chemical, thermal properties, surface characteristics, termite resistance and physico-mechanical properties of urea formaldehyde-bonded oil palm trunk particleboard post heat-treated in palm oil were investigated. Oven dried samples were immersed in palm oil for 24 h prior to expose to temperature of 180, 200 and 220 °C in a laboratory oven for 2 h. Alternation in the chemical composition of treated samples was investigated using Fourier transform infrared spectroscopy (FTIR) analysis. Thermal properties analysis was conducted using Thermogravimetric (TG) and Different scanning calorimetric (DSC) analysis. Surface characteristics were checked using scanning electron microscopy (SEM) while resistance against subterranean termite, Coptotermes curvignathus, was evaluated. Physcial and mechanical properties of the samples was assessed based on anti-swelling efficiency (ASE), water repellency efficiency (WRE), bending and internal bonding strength. Degradation of hemicellulose shown in FTIR spectra has contributed to the improvement in dimensional stability. Oil-covered particles as shown in SEM give the particleboard lower water uptake. Treated samples also possess better thermal stability and better resistance against termites as the weight loss caused by termites reduced from 25.6% to 11.0%. Generally, improvement in dimensional stability accompanied by severe reduction in mechanical strength were recorded in the treated samples