PREPARATION AND CHARACTERIZATION OF ELECTROSPUN NANOFIBERS WITH RECYCLED POLYVINYL BUTYRAL FROM AUTOMOBILE WINDSHIELDS


Thesis Type: Postgraduate

Institution Of The Thesis: Gazi University, Fen Bilimleri Enstitüsü, KİMYA MÜHENDİSLİĞİ ANA BİLİM DALI, Turkey

Approval Date: 2021

Thesis Language: Turkish

Student: Burcu GÜNER

Supervisor: Nursel Dilsiz

Abstract:

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 ºC 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.

Key Words : E lectrospinning, PVB, laminated glass, recycling, nanofiber