Self-healable supramolecular vanadium pentoxide reinforced polydimethylsiloxane-graft- polyurethane composites

Abstract

The self-healing ability can be imparted to the polymers by differentmechanisms. In this study, self-healing polydimethylsiloxane-graft-polyurethane (PDMS-g-PUR)/Vanadium pentoxide (V<inf>2</inf>O<inf>5</inf>) nanofiber supramolecular polymer composites based on a reversible hydrogen bonding mechanism are prepared. V<inf>2</inf>O<inf>5</inf> nanofibers are synthesized via colloidal route and characterized by XRD, SEM, EDX, and TEMtechniques. In order to prepare PDMS-g-PUR, linear aliphatic PUR having one -COOH functional group (PUR-COOH) is synthesized and grafted onto aminopropyl functionalized PDMS by EDC/HCl coupling reaction. PUR-COOH and PDMS-g-PUR are characterized by 1H NMR, FTIR. PDMS-g-PUR/V<inf>2</inf>O<inf>5</inf> nanofiber composites are prepared and characterized by DSC/TGA, FTIR, and tensile tests. The self-healing ability of PDMS-graft-PUR and composites are determined by mechanical tests and optical microscope. Tensile strength data obtained from mechanical tests show that healing efficiencies of PDMS-g-PUR increase with healing time and reach 85.4 ± 1.2 % after waiting 120 min at 50 °C. The addition of V<inf>2</inf>O<inf>5</inf> nanofibers enhances the mechanical properties and healing efficiency of the PDMS-g-PUR. An increase of healing efficiency and max tensile strength from 85.4 ± 1.2% to 95.3 ± 0.4% and 113.08 ± 5.24 kPa to 1443.40 ± 8.96 kPa is observed after the addition of 10 wt % V<inf>2</inf>O<inf>5</inf> nanofiber into the polymer. © 2021 Elsevier B.V., All rights reserved.