Eco-friendly polymer nanocomposites designed for self-healing applications

Fully biodegradable self-healing nanocomposites were prepared by mixing carbon nanotubes (CNTs)-based carboxyl methyl cellulose (CMC), produced by chemical modification of cellulose, with a commercial biodegradable highly amorphous vinyl alcohol polymer (HAVOH) containing murexide salt. Damaged specimens were allowed to cure by simply touching the cutting sections in a controlled temperature and humidity environment (30 °C and 80%) for a period of 48 h. The healing efficiency of the samples, evaluated by the recovery of the "Storage Modulus" determined by dynamic-mechanical analysis (DMA) of healed samples, manifests a temperature-dependence behaviour. For temperatures above 50 °C, an almost complete recovery (100%) was observed for the sample of HAVOH containing a solubilized murexide salt. The presence of CNTs-based CMC imparts improved mechanical properties. Maximum values for healing efficiency were observed between 30 and 80 °C.