Biodegradable nanocomposites based on starch/polycaprolactone/compatibilizer ternary blends reinforced with natural and organo-modified montmorillonite

Abstract

In this work, biodegradable polymer/clay nanocomposites were prepared. The matrices used were based on blends of Polycaprolactone (PCL) and Anhydride-Functional Polycaprolactone (PCL-gMA) with Thermoplastic Starch (TPS). Nanocomposites films based on PCL/TPS and PCL/PCL-g-MA/TPS blends reinforced with 1wt.% and 3wt.% of natural montmorillonite and two organo-modified ones were prepared by melt intercalation followed by compression molding. The study was designed focusing on packaging applications. Grafting maleic anhydride onto PCL was efficient to improve PCL/TPS compatibility but did not modified matrix/nanoclay interaction. Matrix compatibilization and nanoclays increased the Young´s modulus and slightly decreased the maximum stress of the TPS/PCL matrix. Nanoclay functionalization improved nanoclay dispersion in the blends but it was not reflected in mechanical properties improvements. The water adsorption of the compatibilized matrix was reduced after clay incorporation. A slight decrease in the biodegradation rate was observed with the addition of nanoclay.