Preparation and characterization of electrospun nanofibers with recycled polyvinyl butyral from automobile windshields

The aim of the thesis study is to recycle polyvinyl butyral (PVB) which is used as an intermediate layer in waste car windshields, to prepare random and alligned nanofiber material by using the electrospinning method with recycled PVB and to perform characterization studies. The recycling process was carried out by soaking the waste car windshield in tetrahydrofuran (THF) overnight, then adding n-Hexane to the solution containing the glass and polymer separated from each other and precipitating the PVB. The precipitate was dried to obtain recycled waste polyvinyl butyral (W-PVB). In the next step, solutions containing 20% by mass (w / v) recycled PVB and commercial PVB film were prepared in the ratio of 70:30 (v / v) tetrahydrofuran (THF): dimethylformamide (DMF) solvent mixture by volume. Nanofibers are produced with static and rotating collectors to obtain random and oriented structures. Chemical, morphological and thermal properties of nanofibers were determined by Fourier transform infrared microscope (FTIR), nuclear magnetic resonance spectroscopy (NMR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), atamic force microscopy (AFM) and surface contact angle analysis. FTIR showed that all recycled materials prepared according to NMR spectra results were in the same chemical structure as the control group after recycling and electrospinning processes, and that the XRD patterns preserved the amorphous structure of the PVB. According to SEM and AFM results, all of the nanofibers were prepared without beads, and uniform morphology. In addition, W-PVB and C-PVB nanofibers prepared in the rotating collector produced in alligned morphology as expected. DSC thermograms showed that when C-PVB and W-PVB nanofibers were compared, the glass transition temperature (Tg) values of W-PVB nanofibers were 61-64 C and 57-59 ºC for C-PVB nanofibers in parallel with their plasticizer content. W-PVB and C-PVB nanofibers showed high hydrophobic properties with contact angle values above 130º. As a result, it has proved possible to produce W-PVB electrospun nanofibers with successfully recycled by chemically from waste car windshields and they are an extremely suitable candidate for use in a wide variety of applications such as textiles, coating, filtration and adsorption.