Recent Past about WPC Work木塑复合材料的研究工作.pdfVIP

Chapter 4 Recent Past about WPC Work 4.1 Wood–fiber/Plastic Composites (WPCs) In recent years, significant efforts have been made to manufacture thermoplastic composites using such natural fibers as wood sawdust, wheat straw, nut shell fiber, and jute fiber [1–3]. The rationable behind these efforts is that the use of natural fibers offers several benefits, including low cost, high specific properties, renewable nature, and biodegradability. Wood fibers are the most favored form of fibers in commercial usage. Because of their high specific stiffness and strength, Wood– fiber/Plastic Composites (WPCs) are a cost-effective alternative to many plastic composites or metals [4]. Wood fiber is a non-abrasive substance, which means that relatively large concentrations of this material can be incorporated into plastics without causing serious machine wear during blending and processing. In spite of their higher price, WPCs are becoming increasingly acceptable to consumers as a replacement for natural wood due to such advantages as durability, color perma- nence, resistance to degradation and fungal attacks, and reduced maintenance. Furthermore, adding wood fibers to plastic products makes good use of waste wood. WPCs are mainly employed in building products, such as decking, fencing, rails, door and window profiles, and decorative trims. Moreover, these composites are also gaining acceptance in automotive and other industrial applications [5]. Polyolefins such as PE and PP are the most commonly used polymer matrix for WPCs because of its relatively low processing temperature and good processability [6]. However, the low compatibility between the hydrophilic wood fiber and hydrophobic polymer matrix is one of the major reasons for limited use of wood fiber as reinforcement. In many cases, poor mechanical and physical properties of a wood fiber composite can be attributed to the weak fiber-matrix interfacial b