Synthesis And Characterization Of Polyacrylonitrile -based Carbon Nanofibers

Abstract

Bu çalışma kapsamında karbon nanoelyaf üretimi PAN tabanlı malzemelerden üretilmiştir ve süreç optimizasyonu yapabilmek adına önce homopolimer ile çalışıp daha sonra polyakrilonitril-ko-itakonik asit ve polyakrilonitril-ko-akrilik asit polimerleri çeşitli besleme oranlarında sentezlenmiştir. Bütün polimelerin dimetilformamid (DMF) ile çözeltileri hazırlanmıştır ve bu çözeltiler oda sıcaklığında elektro çekim ünitesine beslenmiştir. Homopolimer ve ko-polimerden elde edilen PAN tabanlı nanoelyaf matları önce oksidasyon sonra düşük sıcaklık karbonizasyon işlemlerine tabi tutulmuştur. Termal özellikler, diferansiyel taramalı kalorimetre ve termal gravimetrik analiz cihazı ile saptanmıştır. Fourier dönüşümlü kızılötesi spektroskopi- attenuaded total reflaectance (FTIR-ATR) cihazı sayesinde polimerlerin ve nanoelyafların kimyasal yapısı incelenmiştir. Yüzey morfolojisi taramalı elektron mikroskop (SEM) ile incelenmiştir. Nanoelyaf matlarının mekanin özellikleri DMA yardımı ile saptanmıştır.

This study has two main goals, first one is synthesis a co-polymer of polyacrylonitrile (PAN) and second aims is producing a carbon nanofibers out of homo-polymer PAN and co-polymer of PAN and compression between these two products. This study consists of two main parts. First part of it to synthesis a co-polymer of PAN, in this perspective, acrylic acid (AA), itaconic acid (IA) and acrylonitrile (AN) were used as a raw material for polymerization reactions and copolymers were synthesized by using ammonium persulfate (APS) as an oxidant. Polymerization medium was water and dimethylformamide (DMF) mixture. According to monomer weight, feeding ratio different co-polymerization reactions was carried under same co-polymerization conditions. Synthesized co-polymers were investigated by Fourier Transform Infrared Spectroscopy-Attenuated Total Reflection (FTIR-ATR) spectroscopy and their thermal behavior was examined by using Differential Scanning Calorimeter (DSC) and Thermal Gravimetric Analyzer (TGA).Results show that, addition of monomers to get co-polymer was decreased the Tg value of the co-polymer of PAN compared to homo polymer. Oxidized and carbonized samples were characterized by using DMA for their mechanical properties and for thermal properties DSC and TGA were used and for structural analysis, FTIR-ATR spectroscopy was used. For all steps, surface morphology of the fibers have been observed with Scanning Electron Microscope (SEM).