Polysaccharides cellulose whiskers

Although cellulose is the supreme example of a predominantly vegetable natural polymer, exotic animal species are known to produce this polysaccharide and, more particularly, some of its most regular manifestations. Thus, the tunicate mollusc has became the very symbol associated with cellulose whiskers (i.e. extremely regular nanorods with remarkable mechanical and rheo-modifying propraties) as described in Chapter 19. 

Stable aqueous suspensions of polysaccharide nanocrystals can be prepared by the acid hydrolysis of vegetable biomass. Different descriptors of the resulting colloidal suspended particles are used, including whiskers, mono-crystals and nanocrystals. The designation whiskers is used to describe elongated rod-like nanoparticles. These crystallites have also often been referred in the literature as microfibrils, microcrystals or microcrystallites, despite their nanoscale dimensions. Most of the studies reported in the literature refer to cellulose nanocrystals. A recent review described the properties and applications of cellulose whiskers in nanocomposites [31]. 

Dong XM, Revol J-F, Gray DG (1998) Effect of microcrystallite preparation conditions on the formation of colloid crystals of cellulose. Cellulose 5 19-32 Dubief D, Samain E, Dufresne A (1999) Polysaccharide microcrystals reinforced amorphous poly (beta-hydroxyoctanoate) nanocomposite materials. Macromolecules 32 5765-5771 Dufresne A (2000) Dynamic mechanical analysis of the interphase in bacterial polyester/cellulose whiskers natural composites. Compos Interfaces 7 53-67 Dufresne A (2006) Comparing the mechanical properties of high performance polymer nanocomposites from biological sources. J Nanosci Nanotechnol 6 322-330 Dufresne A, Vignon MR (1998) Improvement of starch film performances using cellulose microfibrils. Macromolecules 31 2693-2696... 

Ljungberg N, Cavaille J-Y, Heux L (2006) Nanocomposites of isotactic polypropylene reinforced with rod-like cellulose whiskers. Polymer 47 6285-6292 Lu Y, Weng L, Cao X (2005) Biocomposites of plasticized starch reinforced with cellulose crystallites from cottonseed linter. Macromol Biosci 5 1101-1107 Lu J, Wang T, Drzal LT (2008) Preparation and properties of microfibrillated cellulose polyvinyl alcohol composite materials. Compos Part A 39A 738-746 Magalhaes WLE, Cao X, Lucia LA (2009) Cellulose nanocrystals/cellulose core-in-shell nanocomposite assemblies. Langmuir. doi 10.1021Aa901928j Malainine ME, Mahrouz M, Dufresne A (2005) Thermoplastic nanocomposites based on cellulose microfibrils from Opuntiaficus-indica parenchyma cell. Compos Sci Technol 65 1520-1526 Marchessault RH, Sundararajan PR (1983) Cellulose. In Aspinall GO (ed) The polysaccharides. Academic, New York... 

Li Q, Zhou J, Zhang L (2009) Structure and properties of the nanocomposite films of chitosan reinforced with cellulose whiskers. J Polym Sci 47 1069-1077 Lin N, Yu J, Chang PR, Li J, Huang J (201 la) Poly(butylene succinate)-based biocomposites filled with polysaccharide nanocrystals Structure and properties. Polym Compos 32 472-482 Lin M-F, Thakur VK, Tan EJ, Lee PS (2011b) Surface functionalization of BaTiOa nanopaiticles and improved electrical properties of BaTi03 1yvinylidene fluoride composite. RSC Adv 1 576-578... 

Surprisingly, the association between TPS and cellulose fibres (polysaccharide-based composites) has been little analysed. In the literature, cellulose fillers used in association with a plasticized starch matrix are commercial paper fibres,10 potato pulp microfibrils,11 12 tunicin whiskers and paper bleached pulp.13-14 The literature reports that these cellulose fillers improve the tensile strength. Besides, the composite water sorption seems to be decreased. This behaviour is related to the well known lower water uptake of cellulose compared to starch.10-14... 

Polysaccharides are good candidates for renewable nanofillers because they have partially crystalline structures conferring interesting properties. Two important types of nanofillers have been developed from cellulose, namely whiskers and nanocrystals. Whiskers have also been developed from chitin while starch has been used for preparation of nanocrystals. 

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