Synthesis and liquid crystalline behavior of random copolymer of poly(ethylene oxide) macromonomer and liquid crystalline monomer by the photon transmission technique
Yükleniyor...
Dosyalar
Tarih
2005-12
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Taylor & Francis Inc
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Random copolymers of poly(ethylene oxide) macromonomer with p-vinylbenzyl end-functional group (PEOVB) and liquid crystalline monomer, namely 6-(4-cyanobiphenyl-4'-oxy)hexyl acrylate (COA), were prepared by conventional free radical polymerization. A living anionic polymerization technique was employed for the synthesis of PEO macromonomers bearing p-vinylbenzyl moiety at one end. The photon transmission method was also applied to study the phase transitions of COA monomer and its random copolymer with PEO. It was found that, for both samples, the nematic-smectic A transition is continuous, but the critical fluctuation regions do not allow to obtain 3D XY values. Instead, we have obtained the values close to mean field regime. Scaling of thermal hystersis for random copolymer sample near the nematic-isotropic transition was studied as well. Thermal hysteresis loops were produced under linearly varying temperature. It was shown that the areas of the hysteresis loops scale with the temperature scanning rate with an exponent being equal to 0.614 which is in good agreement with the field-theoretical value.
Açıklama
O. P. and Y. Y. thank the Academy of Sciences of Turkey (TUBA) for partial support.
Anahtar Kelimeler
Transfer radical polymerization, A tricritical point, Phase-transitions, Thermal hysteresis, Crossover, Model, Methacrylate, Polymers, Systems, Field, Smectic-a-phase, Tricritical behavior, Transitions, Polymerization, Point
Kaynak
Journal of Macromolecular Science - Pure and Applied Chemistry
WoS Q Değeri
Q3
Scopus Q Değeri
Q2
Cilt
A42
Sayı
12
Künye
Yıldız, S., Yılmaz, F., Özbek, H., Pekcan, M. Ö., Ito, K. & Yağcı, Y. (2005). Synthesis and liquid crystalline behavior of random copolymer of poly(ethylene oxide) macromonomer and liquid crystalline monomer by the photon transmission technique. Journal of Macromolecular Science - Pure and Applied Chemistry, 42(12), 1573-1588. doi:10.1080/10601320500246602
