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Polyurethane (PU)-polypyrrole (PPy) composite films and nanofibers were successfully prepared for the purpose of combining the properties of PU and PPy. Pyrrole (Py) monomer was polymerized and dispersed uniformly throughout the PU matrix by means of oxidative polymerization with cerium(IV) [ceric ammonium nitrate Ce(IV)] in dimethylformamide. Films and nanofibers were prepared with this solution. The effects of the PPy content on the thermal, mechanical, dielectric, and morphological properties of the composites were investigated with differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), Fourier transform infrared (FTIR)-attenuated total reflection (ATR) spectroscopy, dielectric spectrometry, and scanning electron microscopy. The Young's modulus and glass-transition temperatures of the composites exhibited an increasing trend with increases in the initially added amount of Py. The electrical conductivities of the composite films and nanofibers increased. The crystallinity of the composites were followed with DSC, the mechanical properties were followed with DMA, and the spectroscopic results were followed with FTIR-ATR spectroscopy. In the composite films, a new absorption band located at about 1650 cm À1 appeared, and its intensity improved with the addition of Py. The studied composites show potential for promising applications in advanced electronic devices.

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The oxidative polymerization of pyrrole (Py) by cerium(IV) on Poly(Acrylonitrile- co-Vinyl Acetate) matrix was performed. Nanofibers were obtained from this solution by the electrospinning method. A new absorption band was observed corresponding to the CH in plane vibration of polypyrrole (PPy) by Fourier transform infrared-attenuated total reflectance spectrophotometric analysis. A linear relationship was determined between the absorbance ratios of functional groups corresponding to the conjugated polymeric units and initial Py concentrations in the presence and absence of Py. Scanning electron microscope images indicated that the diameters of nanofibers were dependent on PPy content and that the average nanofiber diameters were reduced with increasing the initially added Py concentration. The alternating current conductivity of nanofibers was increased with frequency, particularly in the higher frequency region (> 105 Hz).

The adhesion strength enhancement of oxygen plasma pre-treated laminated polypropylene nonwoven fabrics using two different types of adhesives was investigated in this study. Fabric surface modification was performed using low-pressure, radio-frequency oxygen plasma treatment. Effect of plasma treatment on fabric surface wettability was determined by vertical wicking measurements. Wettability of highly hydrophobic polypropylene nonwoven samples dramatically increased with increasing plasma power and exposure time. Plasma-treated polypropylene fibers showed rougher surfaces with increased plasma power and treatment times. X-ray photoelectron spectroscopy (XPS) analysis showed that oxygen plasma treatment of polypropylene fiber surface led to a significant increase in atomic percentage of oxygen compound responsible for hydrophilic surface. Peel strength enhancement of produced laminated fabrics was observed for plasma-treated samples compared to untreated samples. PU-based adhesive attached on the surface of both plasma-treated and untreated polypropylene nonwoven, filling the spaces between the fibers due to the penetration of the adhesive agent. The improvement in surface wettability of polypropylene nonwoven and the introduced sites through oxygen plasma treatment resulted in good adhesive bonding. For both adhesives, peel strength improvement of produced laminated fabrics was