Preparation of <i>in situ</i> polymerized polypyrrole-modified braided cord and its electrical conductivity investigation under varied mechanical conditions

Abstract With the advancement of flexible electronic textiles, electronic braided cords have garnered significant attention in smart wearable fields by integrating electronic functionalities while preserving textile characteristics such as softness, breathability, and comfort. However, their electrical conductivity suffers varying degrees of degradation under mechanical conditions including friction, stretching, and flexure. This study employed polyester braided cord as a substrate and optimized the preparation of polypyrrole (PPy)-modified braided cord through in situ polymerization combined with orthogonal experimental design. The degradation mechanisms of conductivity under different mechanical conditions were systematically investigated. Experimental results demonstrate that the optimal conductivity (63 S·m −1 ) was achieved when the pyrrole monomer concentration, FeCl₃·6H₂O concentration, pre-immersion time, and polymerization time were set to 0.2, 0.2 mol·L −1 , 4 h, and 9 h, respectively. Although external forces can damage PPy conductive pathways on the cord surface, leading to conductivity loss, the modified cord exhibits excellent friction resistance, stretch tolerance, flexural durability, and stable conductivity under low-load conditions. This research provides critical scientific insights for prolonging the service life of electronic braided cords and their integrated smart textiles.