Development of Stretchable,\nSelf-Healing Polyvinyl\nNeodecanoate and Its Nanocomposites with MWCNT for Semiconducting\nTape Applications

This article reports the development\nof a self-healing and self-adhesive\nhomopolymer of vinyl neodecanoate (VNDc) using a bulk polymerization\nprocess. The obtained homopolymer PVNDc is found to have a subzero\nglass transition temperature (<i>T</i><sub>g</sub>) of −3\n°C and an optical transparency comparable to that of inorganic\nglass. Moreover, a series of copolymers of VNDc with methyl methacrylate\n(MMA) are prepared using a solution polymerization process to understand\nthe effect of the second comonomer on the self-healing mechanism,\nadhesion, and various other properties. Since PMMA is a rigid and\ntransparent polymer, the homopolymer PVNDc is modified with this comonomer\nto improve the toughness of the soft, stretchable homopolymer backbone.\nWith the introduction of MMA with VNDc, the stretchability, self-healing,\nand adhesion properties were found to disappear due to the substitution\nof a longer pendant group by a smaller one, disrupting the interlocking\nof tertiary carbons present at the long-chain end of the VNDc monomer\nresidue in the homopolymer backbone and reduction in the van der Waal\ninteraction when MMA is introduced in place of VNDc, respectively.\nThe PVNDc homopolymer is a sticky adhesive material that, on further\nsolution blending with different wt % of conductive fillers of MWCNT,\nshows bulk electrical conductivity of 9.6 × 10<sup>–4</sup> S/cm (semiconducting) to fabricate a stretchable semiconductive\ntape. A PVNDc is a superstretchable, self-healing, and adhesive material\nthat heals itself without external stimuli like pressure, temperature,\nand cross-linking agents. This matrix property might find its potential\napplication in various flexible devices, such as semiconductive adhesives\nin electronic circuits and semiconducting tapes.