Macroporous poly(vinyl chloride)-polypyrrole composites with piezoresistive behaviour

Flexible macroporous composites based on commercially ubiquitous poly(vinyl chloride) (PVC) coated with thin layer of conducting polypyrrole (PPy) were investigated for their piezoresistive characteristics. Macroporous discs were achieved via a thermally assisted and solvent free approach employing common salt as sacrificial template. Coating of PPy was obtained via vapor phase oxidative polymerization and two type of composites (PPyF60 and PPyF75) with different compressibility were prepared by varying PVC-salt ratio (1:4 and 1:5). Composite PPyF60 exhibited higher compressive strength (5.34 MPa vs 3.78 MPa) due to less porosity. In terms of piezoresistive behaviour however PPyF75 exhibited higher pressure sensitivity (0.149 kPa(-1)) and gauge factor (8.22). Both composites showed good signal stability during continuous cyclic strain and dynamic pressure. (C) 2020 Elsevier B.V. All rights reserved.