Nano/micro Cellulose Crystals Reinforced Polyurethanes

MARCOVICH, NORMA E.; AUAD, MARÍA L.; NUTT, STEVE R.; ARANGUREN, MIRTA I.

Los Cocos,Córdoba, Argentina

Simposio; III Argentine-Chilean Polymer Symposium, ARCHIPOL III; 2005

Los Cocos,Córdoba, Argentina, 4 al 7 de diciembre de 2005) 2 páginas Cellulose is one of the most abundant materials in nature, where it performs as the main structural material in the conformation of plants and also some animals (Eichhorn and Young, 2001). Cellulose fibers display a unique structural hierarchy: they are composed of an assembly of microfibrils which are in the form of slender and nearly endless rods. Upon the action of strong acids, these microfibrils break down into short crystalline rods or ?cellulose microcrystals (CC)? ranging from few hundreds of nanometers to a few microns (Heux, et al, 2000). Nevertheless, the inherent polar and hydrophilic nature of cellulose and the nonpolar characteristics of most synthetic polymers result in difficulties in compounding the filler and the matrix, and therefore in achieving acceptable dispersion levels, which usually lead to poor performance composites. An alternative way to palliate this restriction consists of obtaining both components (matrix and filler) dispersed in water, and thus, most of the works found in literature dealt these mixtures (Dong et al, 1998; Dufresne and Vignon, 1998). In this work, cellulose crystals are dispersed in an organic polar solvent to be incorporated to a polyurethane formulation. The characterizations of the uncured liquid mixture and the final reinforced films are presented and discussed.