Nano/micro Cellulose Crystals Reinforced Polyurethanes

N.E. MARCOVICH; M.L. AUAD; STEVE R. NUTT; M.I. ARANGUREN

Los Cocos, Córdoba, Argentina

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

Cellulose crystals were dispersed in an organic polar solvent and then incorporated to a polyurethane formulation. The uncured liquid mixture and the final reinforced films were characterized by rheological measurements and tensile tests. The rheology of the suspensions indicates a percolation behavior of the systems with a critical concentration threshold of crystals of about 0.6% vol. (in agreement with reported theoretical model calculations). The cured systems show a higher percolation threshold, but the increment in the Young modulus after the critical concentration is not as large as expected.