Chitosan-containing electrospun poly(ethylene oxide)-polybutadiene-CNT fibers

Cross-linked polymer composite fibers are gaining more and more interest in the fields of drug delivery, bone regeneration and biomineralization. This study focuses on the replacement of the radical initiator by photoinitiation via benzophenone, resulting in poly(ethylene oxide)-polybutadiene-carbon nanotube (PEO-PBu-CNT) nanofibers. The inclusion of small amounts of CNTs increases the rupture temperature and the first glass transition temperature Tg1 of the composite by 28 and 23 K, respectively, while decreasing the second glass transition temperature Tg2 by 20 K determined by dynamic mechanical analysis. A twice higher initial storage modulus of ~44 MPa can be detected for the CNT-containing samples, indicating the stiffening effect due to CNT addition. Primary X-ray diffraction peaks of PEO shift by 0.42° towards lower angles by the inclusion of CNTs, accounting for the generation of free volume within the polymer composite. Two orders of magnitude increase in Bode magnitude with a rise in Bode angle from 6° to 56° is detected by electrochemical impedance spectroscopy for the UV-cured PEO-PBu-CNT. Entanglement between the fibers, as well as a rough surface with a rigid structure, is observed upon small CNT additions. Finally, attenuated total reflectance—Fourier transform infrared and Raman spectroscopy allow the detection of the main peaks and intensity changes of these polymer composite structures for the UV-cured and uncured states.