Preparation and characterization of biodegradable polycaprolactone/multiwalled carbon nanotubes nanocomposites

Blends of the biodegradable polycaprolactone (PCL) and multiwalled carbon nanotubes (MWNTs) were prepared by means of a melt blending method. To conquer the poor compatibility between PCL and MWNTs, the acrylic acid grafted polycaprolactone (PCL‐ g ‐AA) and the multihydroxyl functionalized MWNTs (MWNTs‐OH) were used as alternatives for the preparation of blends. As the comparison between PCL‐ g ‐AA/MWNTs‐OH and PCL/MWNTs blends, the former gave much better thermal and mechanical properties than the latter; for examples, 77°C increase in the initial decomposition temperature and 13.3 MPa in the tensile strength at break with the addition of only 5 wt %, due to the formation of ester groups through the reaction between carboxylic acid groups of PCL‐ g ‐AA and hydroxyl groups of MWNTs‐OH. Finally, the optimal amount of MWNTs‐OH was 5 wt % because excess MWNTs‐OH caused separation of the organic and inorganic phases and lowering their compatibility. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009