Design and Characterization of Biodegradable Self-healing Nanocomposites

The growing interest in self-healing systems is closely linked to the possibility of developing products with an extended life span, thereby enabling energy savings and a reduction in the waste of resources. Among the strategies employed for producing self-healing materials, a relevant role is played by those using biodegradable materials. In this context, this research proposes the development of materials with auto-repair functionality based on a fully biodegradable commercial polymer, namely the highly amorphous vinyl alcohol polymer (HAVOH). The formulated samples have been obtained by mixing the HAVOH matrix with a masterbatch (also biodegradable) composed of carboxyl methyl cellulose (CMC) modified with Multiwall Carbon Nanotubes (MWCNTs), which make the samples electrically conductive and improve their mechanical performance. Furthermore, Murexide (M) salts have been added to the composition to improve the auto-repair ability of the materials. The evaluation of the electrical properties has attested that using 5% by weight of MWCNTs allows obtaining samples with an electrical conductivity value of around 10–4 S/m. The self-healing efficiency has been investigated by monitoring the recovery of the “Storage Modulus” evaluated by dynamic-mechanical analysis (DMA) of healed samples. The self-healing behavior is temperature-dependent, with the materials exhibiting the highest values of healing efficiency between 30 and 80 °C. The obtained results attest to a significant step forward in the design of self-healing green nanocomposites by employing natural resources.