Wood-polymer composites WPCs

Traditional composite panels are made from veneers and from mat-formed eomposites bonded by adhesive. More recently wood has also been combined (eompression moulded or extruded) with synthetic polymers, e.g. thermoplastic polymers, to make wood-polymer composites (WPC). WPC products have been growing very rapidly in the recent years, especially in the deeking market, where Woleott (2004) observed that their market share has grown from 2% in 1997 to 14% in 2003. Further, much research work has explored the use of fibre-reinforced polymers (FRP) to enhance the structural performance of engineered wood eomposites, ealled FRP-wood hybrid composites (Dagher et ai, 1998 Shi, 2002). 

T. Dombrowski. Carbonate minerals in wood polymer composites (WPC). In WPCs 2006, The Changing Technology in WPCs. The First World Congress on Woodfiber/ Plastics and Related Composites, San Francisco, CA, April 2-4, 2006. 

A large number of studies have been made so far in this comr prehensive area of research. However, our survey has shown that commercially available wood-polymer composite (WPC) products are few. This is due primarily to their cost as compared to other competitive products, and secondarily, due to the difficulty of... 

Islam et al. (2012) reported that the mechanical and morphological properties of wood polymer composites (WPCs) were improved significantly after pretreatment with alkali solution. For his study, methyl methacrylate (MMA) and styrene (ST)... 

The enthusiasm in this field is explained by the number of potential applications. For example wood-polymer composites (WPC), mostly manufactured through extmsion and injection moulding processes are used in automotive (dashboards or screen-doors of the vehicles) and construction applications (interior floor coverings, profiles for doors and windows, ornamental panels, external shutters, pavements, garage, or entrance doors). Replacement of wood products for building applications such as particleboard and fiberboard materials or injection mouldable wood is another area where natural fibers are generating increased interest. 

Figure 2 Creep-recovery tests of chemically treated woods. U, untreated wood Fs, vapor phase formalization F, liquid phase formalization A, acetylation PO, etherification with propylene oxide MG, treatment with maleic acid and glycerol PFl, impregnation with low molecular weight phenol-formaldehyde resin PEG-ICP, impregnation with polyethylene glycol (PEG-IOOO) WPC, formation of a wood- polymer composite (PMMA) WIC, formation of a wood-inorganic material composite.

D. Dean. Development of enhanced anhydride coupling agents for wood polymer composites. In WPC Conference 2004 Realizing the Full Potential, Baltimore, MD, October 11-12. 

Yap MG, ChiaSLHL, Teoh SH (1990) Wood-Polymer composites from tropical hardwoods I. WPC properties. J Wood Chem Technol 10 1-19... 

In this chapter, several classes of biopolymers are discussed. First, biobased and biodegradable polymers are considered, together with wood plastic composites (WPCs) (Section 8.2). A field of increasing importance is the application of polymers in medicine, particularly their use in the human body (Section 8.3). 

These materials are from renewable sources and are often made from plant materials that can be grown year after year and should come from agricultural nonfood crops. Biodegradable polymers are broken down into CO 2 and water by microorganisms. Although biopolymers may be able to help solve the disposal problems of current plastic packaging, it is not clear if they can really deliver on this promise and whether there is possible competition with the food chain. Cellulose is the most common biopolymer and organic compound on Earth. Other examples are starch, PHB (polyhydroxybutyrate), natural fibers, silk, and wood plastic composites (WPC). 

A widely used matrix materiai for wood plastic composites (WPC) is polypropylene (PP). However, the hydrophilic nature of wood lowers the compatibility with the hydrophobic polymer, leading to WPCs with poor dispersions. Therefore, substantial research has been carried out on the surface modification of wood with coupling agents to improve strength properties. Maleated polypropylene has proved to be one of the most suitable materials for improving the interfacial adhesion between wood particles or fibers and polypropylene and hence the mechanical properties of the composite [9]. 

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