Katyonik Polimerizasyondan Foto-polimerizasyona Mekanistik Transformasyon Yöntemiyle Blok Kopolimer Sentezi
Katyonik Polimerizasyondan Foto-polimerizasyona Mekanistik Transformasyon Yöntemiyle Blok Kopolimer Sentezi
Dosyalar
Tarih
Yazarlar
Yıldız, Yasemin
Süreli Yayın başlığı
Süreli Yayın ISSN
Cilt Başlığı
Yayınevi
Fen Bilimleri Enstitüsü
Institute of Science and Technology
Institute of Science and Technology
Özet
ω-uç gurubunda foto aktif N,N’- dietil ditiyokarbamoil (Et2NC(S)S-) grubu taşıyan polimerler, doğrudan UV ışını uygulanarak değişik mimaride blok kopolimerlerin sentezini mümkün kıldığından yaygın olarak tercih edilmektedir. Ayrıca molekül ağırlıklarını ve molekül ağırlığı dağılımlarını yüksek oranda kontrol altında tutmaya olanak sağlayan atom transfer radikal polimerizasyonu (ATRP) son yıllarda en çok araştırılan alanlardan biri olmuştur. Bu çalışmada foto aktif Et2NC(S)S- grubu taşıyan fonksiyonel politetrahidrofuran (C-PTHF), stirenin (St) yaşayan/kontrollü foto polimerizasyonunda ve blok kopolimer sentezinde kullanılmıştır. ω-ucundan fonksiyonlanmış C-PTHF, metil triflorometansülfonat kullanılarak katyonik polimerizasyon yöntemiyle elde edilmiş ve polimerizasyon N,N’-dietil ditiokarbamik asit sodyum tuzu kullanılarak sonlandırılmıştır. Ardından stirenin foto blok kopolimerizasyonu makro başlatıcı olarak C-PTHF ve katalizör olarak bakır klorür (CuCl) kullanılarak gerçekleştirilmiştir. Stirenin foto blok kopolimerizasyonu 300 nm UV radyasyonu altında ve oda sıcaklığında klasik ATRP yöntemlerinin tersine ligand kullanılmaksızın gerçekleştirilmiştir. Buna ek olarak, reaksiyon mekanizmasını aydınlatmak üzere C-PTHF/CuCl/Ligand(Bpy) ve C-PTHF/St başlangıç sistemleri ile blok kopolimerizasyon ve aynı zamanda stirenin kendi kendine polimerleşmesi aynı şartlar altında denenmiştir.
Polymers having photo labile N,N’-diethyl dithiocarbamoyl group (Et2NC(S)S-) at their ω-end are widely preferred as they make possible the synthesis of block copolymers with different architectures by means of UV radiation at room temperature. Also atom radical transfer polymerization (ATRP) is one of the most researched areas as it allows controlling molecular weights and molecular weight distributions. In this study functional polytetrahydrofuran (C-PTHF) containing photo labile Et2NC(S)S- group was employed in the living/controlled photopolymerization of styrene (St) and block copolymers were synthesized. ω-end functionalized C-PTHF, was obtained by living cationic ring opening polymerization using methyl trifluoromethanesulfonate and the polymerization was quenched by the addition of N,N’-diethyl dithiocarbamic acid sodium salt. Afterwards, photo block copolymerization of St was carried out with C-PTHF and cupper chloride (CuCl), as macroinitiator and catalyst respectively. Photo block copolymerization of St was achieved under 300 nm UV radiation at ambient temperature and without ligand on the contrary of usual ATRP methods. In addition block copolymerization of St with C-PTHF/CuCl/Ligand (Bpy) and C-PTHF/St initiation systems and the self polymerization of St were also performed under the identical conditions to investigate the reaction mechanism.
Polymers having photo labile N,N’-diethyl dithiocarbamoyl group (Et2NC(S)S-) at their ω-end are widely preferred as they make possible the synthesis of block copolymers with different architectures by means of UV radiation at room temperature. Also atom radical transfer polymerization (ATRP) is one of the most researched areas as it allows controlling molecular weights and molecular weight distributions. In this study functional polytetrahydrofuran (C-PTHF) containing photo labile Et2NC(S)S- group was employed in the living/controlled photopolymerization of styrene (St) and block copolymers were synthesized. ω-end functionalized C-PTHF, was obtained by living cationic ring opening polymerization using methyl trifluoromethanesulfonate and the polymerization was quenched by the addition of N,N’-diethyl dithiocarbamic acid sodium salt. Afterwards, photo block copolymerization of St was carried out with C-PTHF and cupper chloride (CuCl), as macroinitiator and catalyst respectively. Photo block copolymerization of St was achieved under 300 nm UV radiation at ambient temperature and without ligand on the contrary of usual ATRP methods. In addition block copolymerization of St with C-PTHF/CuCl/Ligand (Bpy) and C-PTHF/St initiation systems and the self polymerization of St were also performed under the identical conditions to investigate the reaction mechanism.
Açıklama
Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2005
Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2005
Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2005
Anahtar kelimeler
foto blok kopolimerizasyon,
yaşayan/kontrollü polimerizasyon,
N,
N’-dietil ditiokarbamoil grubu,
atom transfer radikal polimerizasyonu (ATRP).,
Photo block copolymerization,
living/controlled polymerization,
N,
N’-diethyl ditiocarbamoyl group,
atom transfer radical polymerization (ATRP).