Conductive and thermoactivated flax yarns developed by in situ polypyrrole polymerizations: Interactions with carbohydrate polymers
Résumé
This study investigated the functionalization of flax yarn via in situ chemical polymerization of conductive polypyrrole (FY-PPy) and polypyrrole-silver (FY-PPy-Ag). Voltage-controlled experiments were conducted to assess the electrothermal properties of the modified yarns, with a focus on the Joule effect. FY-PPy exhibited significantly higher electrical conductivity (826 S.m- 1) and thermal conductivity (8583 J.S- 1 m- 1.degrees C- 1) than FYPPy-Ag did, which had values of 505 S.m- 1 and 5616 J.S- 1 m- 1.degrees C- 1, respectively. This enhanced conductivity resulted in a greater temperature increase during Joule heating, with the superior electrothermal performance of FY-PPy linked to the coated material formed during polymerization. Quantitative assessments of the coated conductive material were performed, revealing 25.5 wt% of PPy in the FY-PPy sample and 16.5 wt% of PPy and 26.1 wt% of silver in the FY-PPy-Ag sample. Gas chromatography tests revealed that the cellulosic content of the initial yarn remained unchanged after both functionalization methods were applied; however, the non-cellulosic polysaccharide content decreased significantly due to acidic treatment. Longitudinal tensile tests and sorption-desorption characterizations indicated that FY-PPy retained properties closer to those of the unfunctionalized yarn, whereas FY-PPy-Ag exhibited greater property loss. Our findings provide essential insights into the enhanced characteristics of functionalized flax yarns, highlighting their potential applications in the advanced electronics and composite industries.