Synergistic strengthening of composite films by crosslinking graphene oxide reinforcement and poly(vinyl alcohol) with dicarboxylic acids

Abstract

High strength plastic materials with excellent biodegradability, non-toxicity and economically wide availability are in high demand. Herein, we have demonstrated Graphene oxide (GO) composite of polyvinyl alcohol (PVA) as a potential bioplastic material by chemical crosslinking. For a potential bioplastic material, PVA has to be addressed for its high water absorbing capacity along with improvement in tensile strength and thermal stability. The issues were addressed by enhancing interfacial binding between PVA and GO, a covalent bond between the two is introduced by crosslinking with dicarboxylic acids namely succinic acid(SuA) and adipic acid (AdA). Crosslinking of neat PVA with dicarboxylic acids also resulted in enhanced swelling resistance and thermal stability. The highest improvement in tensile strength and swelling resistance was observed for a GO crosslinked with diacids due to the synergistic effect of reinforcement and crosslinking. Improvement of 225% and 234% in the tensile strength of PVA (31.19) MPa) was observed for 5%GO-PVA samples cross-linked with 6.25 mM adipic acid (AdA) and 7.5 mM succinic acid (SuA), respectively. For the same samples, water uptake was 44% (GO-AdA-CL-PVA) and 29.33% (GO-SuA-CL-PVA) compared to the uncross-linked PVA (359%).