Amine-functionalized thermoplastic polyurethane electrospun fibers prepared by co-electrospinning with 3-aminopropyltriethoxysilane and preparation of conductive fiber mats

Amine-functionalized thermoplastic polyurethane (TPU) electrospun fibers with controllable number of amine groups on fiber surfaces are prepared by co-electrospinning of TPU and 3-aminopropyltriethoxysilane (APS) in DMF/THF 4:6, followed by thermal treatment at 60 °C in a ventilated oven for 24 h. The morphology of the fibers was observed by Field Emission Scanning Electron Microscopy (FESEM), showing a decrease in average fiber diameter with increasing APS content, resulted from significantly increased solution conductivity. The amine groups are homogeneously distributed on the fiber surfaces, as revealed by energy dispersive X-ray spectroscopy (EDX) Si-mapping. Both the Si content measured by X-ray photoelectron spectroscopy (XPS) and NH2 content obtained by chemical titration show an enrichment of APS condensate on the fiber surfaces, which is explained by the higher mobility of APS to TPU during electrospinning. Gold nanoparticles of 16 nm are homogeneously adsorbed on the amine-functionalized TPU fibers. A conductive gold layer with a surface resistivity of 0.3 Ω/sq is formed after electroless plating using the adsorbed gold nanoparticles as the seeds, demonstrating the usefulness of the amine groups in the preparation of TPU fibers with added functionalities.