Thermal forming of chemically modified wood to make high-performance plastic-like wood composites
-
Abstract
Chemically modified wood composites were obtained via the compression moulding of thermoplasticised Aspen (Populus tremula) sawdust. This sawdust was previously prepared by esterification with maleic anhydride (MA) and subsequent oligoesterification with maleic anhydride and glycidyl methacrylate (GMA). The thermoplastic properties of the chemically modified wood resulting from different modification procedures were confirmed and compared by compression-moulding experiments leading to preliminary and final products. An SEM study of the resulting products clearly showed that the oligoesterified wood had partially melted under pressure and temperature, such that the overlapping and surface melting of particles ensured adhesive bonding between those particles. A new type of wood/thermoplastic-wood composite was obtained. In these composites, the melted part of the modified wood plays the role of the cohesive matrix whilst none-melted wood remains as a fibrous reinforcing material. FTIR spectra suggested that changes in the chemical structure of the modified wood are possible during the thermal forming process (e.g. polymerisation of C=C double bonds).
The final composites were yellowish-brown, glossy, plastic-like products that showed interesting physical, mechanical and biological properties. They are water-resistant and dimensionally stable and display good electrical insulating behaviour. Their mechanical properties (bending strength of ca. 64 MPa and tensile strength of ca. 36 MPa) are in the typical range for plastics and conventional wood-fibre/plastic composites, and are superior to common wood products such as fibreboards and particleboards. Furthermore, the outstandingly high internal bond (ca. 3.0 MPa) highlights the totally different adhesion mechanism operating in these new types of composites. Although the novel composites are much more resistant to decay than the original unmodified wood, they remain ultimately biodegradable plastic-like composites.
References
ASTM Standard (1981) D 2017. Accelerated laboratory test of natural decay resistance of woods.Search in Google Scholar
British Standard (1976) BS 2782. Plastics: Part 3: Mechanical tests: Methods 320A to 320F. Tensile strength, elongation and elastic modulus.Search in Google Scholar
British Standard (1994) BS 2782. Plastics: Part 3: Mechanical tests: Method 321. Determination of tensile properties. General principles.Search in Google Scholar
British Standard (1993) BS 2782. Plastics: Part 3: Mechanical tests: Method 335A. Determination of flexural properties.Search in Google Scholar
British Standard (1982) BS 6009-EN 113:1980. Wood preservatives. Determination of toxic values against wood destroying Basidyomicetes cultured on agar medium.Search in Google Scholar
Budinski, K.G. Engineering Materials: Properties and Selection. Fourth Edition, Prentice Hall, New Jersey, 1982.Search in Google Scholar
Harper, C.A. Handbook of plastics, elastomers and composites. Third Edition, McGraw-Hill, New York, 1996.Search in Google Scholar
Kiguchi, M. (1996) Surface modification and activation of wood. In: Chemical Modification of Lignocellulosic Materials. Ed. Hon, D.N. Marcel Dekker, Inc., New York, pp. 197–226.Search in Google Scholar
Maldas, D., Kokta, B.V. (1993) Role of coupling agents and treatments on the performance of wood fiber-thermoplastic composites. In: Wood and Fiber Polymer Composites: Fundamental Concepts, Processes, and Material Options. Ed. Wolcott, M.P. Forest Products Society, pp. 113–120.Search in Google Scholar
Maloney, T.H. (1990) Processing tomorrow’s wood composites. Papers of IUFRO World Congress. Montreal, vol. V, pp. 275–286.Search in Google Scholar
Marcovich, N.E., Reboredo, M.M., Aranguren, M.I. (1996) Sawdust modification: maleic anhydride chemical treatment. Holz Roh- Werkst.54:189–193.10.1007/s001070050164Search in Google Scholar
Matsuda, H. (1987) Preparation of esterified woods bearing carboxyl groups. Wood Science Technol.21:75–88.10.1007/BF00349719Search in Google Scholar
Matsuda, H., Ueda, M., Mori, H. (1988a). Preparation and cross-linking of oligoesterified woods based on maleic anhydride and allyl glycidyl ether. Wood Science Technol.22:21–32.10.1007/BF00353225Search in Google Scholar
Matsuda, H., Ueda, M., Mori, H. (1988b) Preparation and cross-linking of oligoesterified woods based on phthalic anhydride and glycidyl methacrylate. Wood Science Technol.22:335–344.10.1007/BF00353323Search in Google Scholar
Matsuda, H. (1996) Chemical modification of wood. In: Chemical modification of lignocellulosic materials. Ed. Hon, S. Marcel Dekker, Inc., New York, pp. 159–183.Search in Google Scholar
Mohanakrishnan, C.K., Narayan, R., Nizio, J.D. (1993) Reactive extrusion processing of polypropylene-lignocellulosic blend materials. In: Wood and Fiber Polymer Composites: Fundamental Concepts, Processes, and Material Option. Ed. Wolcott, M.P. Forest Products Society, pp. 57–62.Search in Google Scholar
Oksman, K. (1996) Improved interaction between wood and synthetic polymers in wood/polymer composites. Wood Science Technol.30:197–205.10.1007/BF00231633Search in Google Scholar
Rowell, M.R. (1991) Chemical Modification of Wood. In: Wood and Cellulosic Chemistry. Eds. Hon, D.N.-S, Shiraishi, N. Marcell Dekker, Inc., pp. 703–755.Search in Google Scholar
Rowell, R.M. (1992) Opportunities for value-added bio-based composites. FRI Bulletin 177: Pacific Rim Bio-Based Composites Symposium. Eds. Placket, D.V., Dunningham, E.A. New Zeeland Forest Research Institute, pp. 244–251.Search in Google Scholar
Shiraishi, N. (1991) Wood plasticization. In: Wood and Cellulosic Chemistry. Eds. Hon, D.N.-S, Shiraishi, N. Marcel Dekker, New York, pp. 891–906.Search in Google Scholar
Shiraishi, N. (1993). Plasticization of wood and its application. In: Recent research on wood and wood-based materials. Eds. Shiraishi, N., Kajita, H., Norimoto, M. Elsevier Applied Science, London, pp. 155–168.10.1016/B978-1-4831-7821-9.50020-4Search in Google Scholar
Timar, M.C. (1998) Chemically modified wood for thermally formed composites. PhD thesis, Brunel University, UK.Search in Google Scholar
Timar, M.C., Mihai, M.D., Maher, K., Irle, M. (2000a) Preparation of wood with thermoplastic properties. Part 1: Classical synthesis. Holzforschung54:71–76.10.1515/HF.2000.011Search in Google Scholar
Timar, M.C., Maher, K., Irle, M., Mihai, M.D. (2000b) Preparation of wood with thermoplastic properties. Part 2: Simplified technologies. Holzforschung54:77–8210.1515/HF.2000.012Search in Google Scholar
Timar, M.C., Zamfira, S., Mihai, M.D. (2001) Assessing thermoplastic properties of chemically modified wood composites by dielectric analysis. Proceedings of the International Conference “BRAMAT 2001”. Braşov, pp. 390–397.Search in Google Scholar
Walker, J.C.F. (1993) Basic wood chemistry and cell wall ultrastructure: Primary Wood processing. Ed. Walker et al. Chapman and Hall, London. pp. 23–64.Search in Google Scholar
© Walter de Gruyter
Articles in the same Issue
- The effects of initial spacing on wood density, fibre and pulp properties in jack pine (Pinus banksiana Lamb.)
- An improved procedure for isolation of residual lignins from hardwood kraft pulps
- Small angle scattering in the Porod region from hydrated paper sheets at varying humidities
- Application of confocal Raman spectroscopy for the topochemical distribution of lignin and cellulose in plant cell walls of beech wood (Fagus sylvatica L.) compared to UV microspectrophotometry
- UV-microscopic analysis of acetylated spruce and birch cell walls
- On-line study of lignin behaviour in dilute alkaline solution by the SEC-UV method
- Extracellular diffusion pathway for heartwood substances in Albizia julibrissin Durazz.
- New glucosides from Eucalyptus globulus wood, bark and kraft pulps
- Nondestructive characterization of wood by monitoring of local elastic anisotropy and dynamic nonlinearity
- Chemical reaction of maritime pine sapwood (Pinus pinaster Soland) with alkoxysilane molecules: A study of chemical pathways
- Thermal forming of chemically modified wood to make high-performance plastic-like wood composites
- Eco-composite from poly(lactic acid) and bamboo fiber
- Bamboo fiber (BF)-filled poly(butylenes succinate) bio-composite – Effect of BF-e-MA on the properties and crystallization kinetics
- Dimensional changes in Corsican pine (Pinus nigra Arnold) modified with acetic anhydride measured using a helium pycnometer
- Microwave-enhanced release of formaldehyde from plywood
- Artificial weathering of tropical woods. Part 1: Changes in wettability
- Artificial weathering of tropical woods. Part 2: Color change
- Inhibition of fungal degradation of wood by 2-hydroxypyridine-N-oxide
- Microwave treatment to accelerate fixation of copper-ethanolamine (Cu-EA) treated wood
Articles in the same Issue
- The effects of initial spacing on wood density, fibre and pulp properties in jack pine (Pinus banksiana Lamb.)
- An improved procedure for isolation of residual lignins from hardwood kraft pulps
- Small angle scattering in the Porod region from hydrated paper sheets at varying humidities
- Application of confocal Raman spectroscopy for the topochemical distribution of lignin and cellulose in plant cell walls of beech wood (Fagus sylvatica L.) compared to UV microspectrophotometry
- UV-microscopic analysis of acetylated spruce and birch cell walls
- On-line study of lignin behaviour in dilute alkaline solution by the SEC-UV method
- Extracellular diffusion pathway for heartwood substances in Albizia julibrissin Durazz.
- New glucosides from Eucalyptus globulus wood, bark and kraft pulps
- Nondestructive characterization of wood by monitoring of local elastic anisotropy and dynamic nonlinearity
- Chemical reaction of maritime pine sapwood (Pinus pinaster Soland) with alkoxysilane molecules: A study of chemical pathways
- Thermal forming of chemically modified wood to make high-performance plastic-like wood composites
- Eco-composite from poly(lactic acid) and bamboo fiber
- Bamboo fiber (BF)-filled poly(butylenes succinate) bio-composite – Effect of BF-e-MA on the properties and crystallization kinetics
- Dimensional changes in Corsican pine (Pinus nigra Arnold) modified with acetic anhydride measured using a helium pycnometer
- Microwave-enhanced release of formaldehyde from plywood
- Artificial weathering of tropical woods. Part 1: Changes in wettability
- Artificial weathering of tropical woods. Part 2: Color change
- Inhibition of fungal degradation of wood by 2-hydroxypyridine-N-oxide
- Microwave treatment to accelerate fixation of copper-ethanolamine (Cu-EA) treated wood
