Polycaprolactone/modified bagasse whisker nanocomposites with improved moisture-barrier and biodegradability properties

Bagasse whiskers isolated from bleached bagasse pulp were chemically modified with n-octadecyl isocyanate in the presence of dibutyltin dilaurate as a catalyst. The modified cellulose whiskers were used in ratios from 2.5 to 15% with polycaprolactone (PCL) polymer to prepare nanocomposite films by a solution/casting technique. The prepared nanocomposites were characterized with regard to their biodegradability in soil and moisture-barrier, moisture sorption, mechanical, thermal, and thermomechanical properties. The use of the modified cellulose whiskers resulted in improvements in the moisture-barrier, biodisintegration, and tensile properties of PCL. The nanocomposites containing different modified whisker loadings had very low moisture absorption (1.882.49%) after 4 weeks of exposure to 75% relative humidity, but these values were slightly higher than that of neat PCL (1.79%). Modified whiskers in the PCL matrix did not noticeably affect the glass-transition and melting temperatures of PCL. (C) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012