The construction sector is facing significant challenges in transitioning to a defossilised system.While wood-based products have considerable potential,reliance on adhesives derived from fossil fuels poses significan...The construction sector is facing significant challenges in transitioning to a defossilised system.While wood-based products have considerable potential,reliance on adhesives derived from fossil fuels poses significant sustainability concerns.Tannin-based adhesives present a compelling bio-based alternative,offering advantageous bonding properties with the potential to reduce toxicity,minimise fossil resource use,and enhance end-of-life scenarios.Despite extensive research demonstrating the technical potential of tannin-based adhesives,industrial adoption remains limited—partly due to the paucity of studies addressing their environmental impacts.The present study investigates the use of tannin-based adhesives in the production of interior-grade plywood,employing urea-formaldehyde(UF)adhesive as reference.The evaluated formulations incorporate quebracho tannin with hexamine or novel protein-containing ingredients,namely soy protein isolate,soy flour,and tara germ powder.Technical tests assessed bonding quality,bending strength,and modulus of elasticity in five-layer plywood.A cradle-to-grave life cycle assessment(LCA)was conducted,with the novelty of using plywood as the functional unit.One formulation,combining tannin and hexamine,exhibited performance comparable to UF-bonded plywood,meeting EN 310 and EN 314 Class 1 standards.Environmental benefits were notable,with carcinogenic human toxicity reduced by 47%,even without accounting for formaldehyde emissions during the use stage.Fossil resource depletion decreased by up to 13%,and global warming potential from fossil sources fell by 10%,in accordance with EN 15804:2012+A2:2019.These findings provide a foundation for further optimisation,broader application in wood-based panels,and enhanced sustainability in construction.展开更多
Herein,the surface of Moso bamboo was hydrophobically modified by combining O_(2)/N_(2)plasma treatments with polydimethylsiloxane(PDMS)solution treatment as the hydrophobic solution.The effects of plasma treatment pr...Herein,the surface of Moso bamboo was hydrophobically modified by combining O_(2)/N_(2)plasma treatments with polydimethylsiloxane(PDMS)solution treatment as the hydrophobic solution.The effects of plasma treatment process(power and time),PDMS solution concentration,and maceration time on the hydrophobic performance of bamboo specimens were studied,and the optimal treatment conditions for improving the hydrophobicity were determined.Scanning electron microscopy(SEM),fourier transform infrared(FTIR),X-ray diffraction(XRD),and X-ray photoelectron spectroscopy(XPS)were used to analyze the surface morphology,chemical structure,and functional groups in the specimens before and after the plasma and PDMS solution treatments under optimal conditions.Response surface analysis was also performed to determine the optimal treatment conditions.Results show that the hydrophobic performance of the Moso bamboo surface is effectively improved and the surface energy is reduced after the coordinated treatment.The optimal conditions for improving the hydrophobic performance of Moso bamboo surface are a treatment power of 800 W,treatment time of 15 s,O_(2)flow rate of 1.5 L/min,PDMS solution concentration of 5%,and maceration time of 60 min for O_(2)plasma treatment and a treatment power of 1000 W,treatment time of 15 s,N_(2)flow rate of 1.5 L/min,PDMS solution concentration of 5%,and maceration time of 60 min for N_(2)plasma treatment.After treatment,silicone oil particles and plasma etching traces are observed on the bamboo surface.Moreover,Si-O bonds in the PDMS solution are grafted to the bamboo surface via covalent bonds,thereby increasing the contact angle and decreasing the surface energy to achieve the hydrophobic effect.展开更多
文摘The construction sector is facing significant challenges in transitioning to a defossilised system.While wood-based products have considerable potential,reliance on adhesives derived from fossil fuels poses significant sustainability concerns.Tannin-based adhesives present a compelling bio-based alternative,offering advantageous bonding properties with the potential to reduce toxicity,minimise fossil resource use,and enhance end-of-life scenarios.Despite extensive research demonstrating the technical potential of tannin-based adhesives,industrial adoption remains limited—partly due to the paucity of studies addressing their environmental impacts.The present study investigates the use of tannin-based adhesives in the production of interior-grade plywood,employing urea-formaldehyde(UF)adhesive as reference.The evaluated formulations incorporate quebracho tannin with hexamine or novel protein-containing ingredients,namely soy protein isolate,soy flour,and tara germ powder.Technical tests assessed bonding quality,bending strength,and modulus of elasticity in five-layer plywood.A cradle-to-grave life cycle assessment(LCA)was conducted,with the novelty of using plywood as the functional unit.One formulation,combining tannin and hexamine,exhibited performance comparable to UF-bonded plywood,meeting EN 310 and EN 314 Class 1 standards.Environmental benefits were notable,with carcinogenic human toxicity reduced by 47%,even without accounting for formaldehyde emissions during the use stage.Fossil resource depletion decreased by up to 13%,and global warming potential from fossil sources fell by 10%,in accordance with EN 15804:2012+A2:2019.These findings provide a foundation for further optimisation,broader application in wood-based panels,and enhanced sustainability in construction.
基金Zhejiang Provincial Cooperative Forestry Science and Technology Project(No.2023SY05)Zhejiang Provincial Science and Technology Project(No.2024F1065-2).
文摘Herein,the surface of Moso bamboo was hydrophobically modified by combining O_(2)/N_(2)plasma treatments with polydimethylsiloxane(PDMS)solution treatment as the hydrophobic solution.The effects of plasma treatment process(power and time),PDMS solution concentration,and maceration time on the hydrophobic performance of bamboo specimens were studied,and the optimal treatment conditions for improving the hydrophobicity were determined.Scanning electron microscopy(SEM),fourier transform infrared(FTIR),X-ray diffraction(XRD),and X-ray photoelectron spectroscopy(XPS)were used to analyze the surface morphology,chemical structure,and functional groups in the specimens before and after the plasma and PDMS solution treatments under optimal conditions.Response surface analysis was also performed to determine the optimal treatment conditions.Results show that the hydrophobic performance of the Moso bamboo surface is effectively improved and the surface energy is reduced after the coordinated treatment.The optimal conditions for improving the hydrophobic performance of Moso bamboo surface are a treatment power of 800 W,treatment time of 15 s,O_(2)flow rate of 1.5 L/min,PDMS solution concentration of 5%,and maceration time of 60 min for O_(2)plasma treatment and a treatment power of 1000 W,treatment time of 15 s,N_(2)flow rate of 1.5 L/min,PDMS solution concentration of 5%,and maceration time of 60 min for N_(2)plasma treatment.After treatment,silicone oil particles and plasma etching traces are observed on the bamboo surface.Moreover,Si-O bonds in the PDMS solution are grafted to the bamboo surface via covalent bonds,thereby increasing the contact angle and decreasing the surface energy to achieve the hydrophobic effect.
