N-Substitiue pirllerin sentezi ve polimerizasyonu
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Dosyalar
Tarih
2020
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Trakya Üniversitesi Fen Bilimleri Enstitüsü
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
İletken polimerler, metaller ve standart polimerlere ait bazı özellikleri bünyesinde birleştiren kendine has organik yapılı malzemelerdir. Hafif ve korozyona dayanıklı özelliklere sahip bu polimerler sentetik metaller olarak da bilinir ve elektrik akımını metaller gibi iletebilmektedir. Son yıllarda korozonu önleme, elektrokromizm, elektroaktivite ve biyolojik uyum gibi üstün özelliklerinden dolayı iletken polimerler üzerine araştırmalar genişleyerek devam etmektedir. Literatürde üzerinde en çok araştırma yapılmış iletken polimerler poliasetilen, polianilin, polifenilen, polifenilvinilen, polipirol, politiyofen ve polikarbazoldür. Bunlar içerisinde polipirol kolay elde edilebilmesi, iletkenliğinin yüksek olması ve dayanıklı olması sebebiyle özel bir öneme sahiptir. Fakat en önemli dezavantajı ise kırılgan ve işlenmesi zor bir yapıya sahip olmasıdır. Pirol halkasına çeşitli fonksiyonel grupların bağlanması, elde edilen polimerin iletkenlik, çözünürlük, işlenebilirlik gibi fiziksel ve kimyasal özelliklerinde farklılıklar oluşturabilmektedir. Tez çalışmasının amacı N-Substitue piroller sentezlemek ve bu monomerlerin polimerizasyonuyla elde edilen polimerlerin özelliklerini araştırmaktır. Öncelikle üç farklı N-substitue pirol monomeri, 4-(1H-pirol-1-il)fenol, 2,6-dikloro-4-(1H-pirol-1-il)fenol, etil 4-(1H-pirol-1-il)benzoat), Clauson Kaas yöntemi ile 2,5 dimetoksitetrahidrofuran’dan başlanarak sentezlenmiştir. Bu monomerler saflaştırılarak yapıları IR, 1H ve 13C NMR ve yüksek çözünürlüklü kütle spektroskopisi teknikleri kullanılarak aydınlatılmıştır. Bu üç N-substitue pirol monomerine 1-(benzo[d][1,3]dioksol-5-il)-1H-pirol ve (2- (1H-pirol-1-il)etil asetatta dahil edilerek polimerizasyonda kullanılmıştır. Pirol ve N-substitue pirollerin polimerleşmesinde oksidant olarak IBX’in kullanılması çalışmanın orjinal yönlerinden biridir. Literatürde hipervalent iyot reaktiflerinden PİFA ile polimerizasyon çalışması çok az bulunur iken IBX ile literatürde yayınlanmış çalışma bulunmamaktadır. Aynı zamanda hipervalent iyot reaktifleri metal bazlı inorganik katalizörlere verimli bir alternatif sunmaktadırlar. Tüm bu veriler göz önüne alındığında hipervalent iyot bileşiklerinin taşıdığı büyük potansiyel bizi özellikle IBX oksidantı ile N-sustitue pirollerin oksidatif polimerizasyonu konusunda araştırma yapmaya teşvik etmiştir. Polimerleşme reaksiyonlarında IBX’in yanı sıra Potasyum persülfat, Demir (III) klorür, Seryum amonyum nitrat gibi güçlü oksidantlar denenmiş ve en uygun oksidant seçilerek polimerizasyon reaksiyonlarında kullanılmıştır. Ayrıca çözücü, sıcaklık, reaksiyon süresi, oksidant monomer oranı, dopant varlığı gibi parametrelerin verim ve iletkenlik üzerine etkisi incelenmiştir. Elde edilen polimerlerden seçilen örneklerin iletkenlik özellikleri ve yüzey özellikleri belirlenmiştir. İlk aşamada IBX’ in pirol türevlerinin polimerizasyonunda oksidant olarak kullanılıp kullanılmayacağını belirlemek için öncelikle polimerleşme pirol ile IBX varlığında gerçekleştirilmiştir. Oksidant olarak IBX’in kullanıldığı polipirollerin eldesinde; 25 oC ve 50 oC sıcaklıklarda dopant varlığında sentezlenmiş polimerlerin iletkenlikleri göreceli olarak yüksektir. 70 oC de dopant varlığında sentezlenmiş polimerlerin verimleri daha yüksek iken iletkenliklerinin daha düşük olduğu görülmüştür. Bu polipirollerde oksidant/ monomer oranı arttıkça polimerin verimi artmış, en iyi iletkenlik oksidant/monomer oranı 0.5 iken doplanmış polipirollerde gözlenmiştir. Reaksiyon süresinin artışı verimlerde artışa sebep olurken, iletkenlik değerlerinde ise tam tersine azalmayla sonuçlanmıştır. N- substitue piroller, her bir monomer için seçilen en uygun oksidant ile farklı sıcaklık, oksidant/monomer oranı ve reaksiyon sürelerinde oksidatif kimyasal polimerizasyon tekniği ile polimerleştirilmiştir. Sıcaklık, oksidant/monomer oranı ve reaksiyon süresinin artışı verimleri arttırırken, iletkenlikler üzerinde kayda değer bir etki göstermemiştir. Pirol azot’u üzerine bir fonksiyonel grubun bağlanması hem polimerleşmeyi kısıtlamış, hem de elde edilen polimerin iletkenliğini azaltmıştır.
Conductive polymers are the materials which have unique organic structures and combine some properties of metals and standard polymers. These polymers, with light and corrosion – resistant properties, are also known as synthetic metals and they can conduct electrical current like metals. In recent years, studies on conductive polymers have been expanding due to their superior properties such as corrosion prevention, electrochromism, electroactivity and biological compatibility. The most investigated conductive polymers in the literature are polyacetylene, polyaniline, polyphenylene, polyphenylvinylene, polypyrrole, polythiophene and polycarbazole. Among these, polypyrrole has a special importance because it is easy to obtain, has high conductivity and durability. However, the most important disadvantage is that it has a fragile structure and therefore difficult to process. Binding of various functional groups to the pyrrole ring can create differences in the physical and chemical properties of the polymer obtained, such as conductivity, solubility and processability. The aim of the thesis is to synthesize N-Substituted pyrroles and to investigate the properties of polymers obtained by polymerization of these monomers. First three different N-substituted pyrrole monomers, (4- (1H-pyrrol-1-yl) phenol, 2,6-dichloro-4- (1Hpyrrol- 1-yl) phenol, ethyl 4- (1H-pyrrol-1-yl) benzoate) to used in polymerization were synthesized by Clauson Kaas method starting from 2,5 dimethoxytetrahydrofuran. These monomers were purified and their structures were illuminated using IR, 1H and 13C NMR and high resolution mass spectroscopy techniques. These three N-substituted pyrrole monomers were used in polymerization by including 1- (benzo [d] [1,3] dioxol-5-yl) - 1H-pyrrole and (2- (1H-pyrrol-1-yl) ethyl acetate. The use of IBX as an oxidant in the polymerization of pyrrole and N-substituted pyrrole is one of the original aspects of the study. In the literature, there are very rare polymerization studies with PIFA, one of the hypervalent iodine reagents, while there are no published studies in the literature with IBX. At the same time, hypervalent iodine reagents offer an efficient alternative to metal-based inorganic catalysts. Considering all these data, the great potential of hypervalent iodine compounds encouraged us to investigate the oxidative polymerization of N-sustitue pyrroles, especially with the IBX oxidant. In addition to IBX, strong oxidants such as Potassium persulfate, Iron (III) chloride, Cerium ammonium nitrate have been tried in polymerization reactions and the most suitable oxidant has been used in polymerization reactions. In addition, the effects of parameters such as solvent, temperature, reaction time, oxidant monomer ratio, presence of dopant on yield and conductivity were investigated. Conductivity and surface properties of the samples selected from the obtained polymers were determined. In first stage, in order to determine whether IBX can be used as an oxidant in the polymerization of pyrrole derivatives, the polymerization was carried out in the presence of IBX with pyrrole. In obtaining of polypyrroles using IBX as oxidant: The yields and conductivities of doped polymers synthesized at 25°C and 50°C are relatively high. The doped polymers synthesized at 70°C have higher yields and lower conductivity. It was observed that the yield of polymerization increased in direct proportion with oxidant / monomer ratio. The best conductivity was observed in doped polypyrroles when the oxidant / monomer ratio was 0.5. While increased reaction time leads to an increase in yields, on the contrary, conductivity values resulted in a decrease. N-substituted pyrroles were polymerized by the oxidative chemical polymerization technique at different temperatures, oxidant / monomer ratio and reaction times with the most suitable oxidant selected for each monomer. While the increase in temperature, oxidant / monomer ratio and reaction time increased yields, it did not show a significant effect on conductivities. While the increase in temperature, oxidant / monomer ratio and reaction time increased yields, it did not show a considerable effect on conductivities.
Conductive polymers are the materials which have unique organic structures and combine some properties of metals and standard polymers. These polymers, with light and corrosion – resistant properties, are also known as synthetic metals and they can conduct electrical current like metals. In recent years, studies on conductive polymers have been expanding due to their superior properties such as corrosion prevention, electrochromism, electroactivity and biological compatibility. The most investigated conductive polymers in the literature are polyacetylene, polyaniline, polyphenylene, polyphenylvinylene, polypyrrole, polythiophene and polycarbazole. Among these, polypyrrole has a special importance because it is easy to obtain, has high conductivity and durability. However, the most important disadvantage is that it has a fragile structure and therefore difficult to process. Binding of various functional groups to the pyrrole ring can create differences in the physical and chemical properties of the polymer obtained, such as conductivity, solubility and processability. The aim of the thesis is to synthesize N-Substituted pyrroles and to investigate the properties of polymers obtained by polymerization of these monomers. First three different N-substituted pyrrole monomers, (4- (1H-pyrrol-1-yl) phenol, 2,6-dichloro-4- (1Hpyrrol- 1-yl) phenol, ethyl 4- (1H-pyrrol-1-yl) benzoate) to used in polymerization were synthesized by Clauson Kaas method starting from 2,5 dimethoxytetrahydrofuran. These monomers were purified and their structures were illuminated using IR, 1H and 13C NMR and high resolution mass spectroscopy techniques. These three N-substituted pyrrole monomers were used in polymerization by including 1- (benzo [d] [1,3] dioxol-5-yl) - 1H-pyrrole and (2- (1H-pyrrol-1-yl) ethyl acetate. The use of IBX as an oxidant in the polymerization of pyrrole and N-substituted pyrrole is one of the original aspects of the study. In the literature, there are very rare polymerization studies with PIFA, one of the hypervalent iodine reagents, while there are no published studies in the literature with IBX. At the same time, hypervalent iodine reagents offer an efficient alternative to metal-based inorganic catalysts. Considering all these data, the great potential of hypervalent iodine compounds encouraged us to investigate the oxidative polymerization of N-sustitue pyrroles, especially with the IBX oxidant. In addition to IBX, strong oxidants such as Potassium persulfate, Iron (III) chloride, Cerium ammonium nitrate have been tried in polymerization reactions and the most suitable oxidant has been used in polymerization reactions. In addition, the effects of parameters such as solvent, temperature, reaction time, oxidant monomer ratio, presence of dopant on yield and conductivity were investigated. Conductivity and surface properties of the samples selected from the obtained polymers were determined. In first stage, in order to determine whether IBX can be used as an oxidant in the polymerization of pyrrole derivatives, the polymerization was carried out in the presence of IBX with pyrrole. In obtaining of polypyrroles using IBX as oxidant: The yields and conductivities of doped polymers synthesized at 25°C and 50°C are relatively high. The doped polymers synthesized at 70°C have higher yields and lower conductivity. It was observed that the yield of polymerization increased in direct proportion with oxidant / monomer ratio. The best conductivity was observed in doped polypyrroles when the oxidant / monomer ratio was 0.5. While increased reaction time leads to an increase in yields, on the contrary, conductivity values resulted in a decrease. N-substituted pyrroles were polymerized by the oxidative chemical polymerization technique at different temperatures, oxidant / monomer ratio and reaction times with the most suitable oxidant selected for each monomer. While the increase in temperature, oxidant / monomer ratio and reaction time increased yields, it did not show a significant effect on conductivities. While the increase in temperature, oxidant / monomer ratio and reaction time increased yields, it did not show a considerable effect on conductivities.
Açıklama
Anahtar Kelimeler
N-Substitue pirol, Poli(N-Substitue pirol), İletken polimer, Kimyasal polimerizasyon, Dopant, Oksidant, IBX, N-Substituted pyrrole, Poly(N-Substituted pyrroles), Conductive polymer, Chemical polymerization, Dopant, Oxidant, IBX
