ABSTRACT
Since roughly one decade, as documented by the literature cited in the following paragraphs of this chapter, research efforts are being made to overcome the natural limitations imposed on the mechanical properties of plant fibers described above, in order to fully exploit the mechanical reinforcement potential inherent to cellulose. Nanoscale cellulosic reinforcement offers the possibility of circumventing the negative effects of natural and man-made variability on mechanical plant-fiber performance, since only pure, widely defect-free cellulose is used. It is well known that the occurrence of defects in a material is less frequent the smaller the unit volume. In the early days, the effect of drastically improved strength with decreasing fiber diameter (Figure 8.1) has been observed for inorganic reinforcements [12-14]. In view of this observation, the isolation of pure nanoscale cellulose from plant fibers for polymer reinforcement purposes represents a promising way of obtaining strong and stiff reinforcement for a new class of bio-based composites. Due to their excellent properties, such composites should be truly competitive with several current nonbio-based composites and provide new market opportunities for biobased products. In the following paragraphs, a brief overview on the current literature on the properties of cellulose and nanoscale cellulosic reinforcements is given together with promising routes for the production of high-performing cellulose nanofibril-or whiskerreinforced composites.
