Self-Healable Supramolecular Vanadium Pentoxide Reinforced Polydimethylsiloxane-Graft-Polyurethane Composites

Abstract

The self-healing ability can be imparted to the polymers by different mechanisms. In this study, self-healing polydimethylsiloxane-graft-polyurethane (PDMS-g-PUR)/Vanadium pentoxide (V2O5) nanofiber supramolecular polymer composites based on a reversible hydrogen bonding mechanism are prepared. V2O5 nanofibers are synthesized via colloidal route and characterized by XRD, SEM, EDX, and TEM techniques. 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/V2O5 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 V2O5 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 % V2O5 nanofiber into the polymer.

pH responsive cationic guar gum-borate self-healing hydrogels for muco-adhesion

“…To visualize the self-healing on a microscale [ 43 , 44 ], a small tear was made on the 1.0% w/v hydrogel with pH 7.4 placed on a glass plate and observed under the microscope. The self-healing of the hydrogel over time was evident by the microscopic images (Figure S6) of the cut made on the self-healing hydrogel.…”

“…The rheological analysis of self-healing was mentioned in Section 2.3.1 . With reference to previous studies [ 43 , 44 ], to analyze self-healing at a microscopic scale, the hydrogel cut with a blade was observed through a confocal microscope (FluoView FV 3000, OLYMPUS, Tokyo, Japan). The images were taken at intervals of 10 s, 1 min, 5 min, 1 h, and 5 h.…”