End-chain and mid-chain functional macrophotoinitiators of poly(ε-caprolactone) and their molar mass effects on strong electrorheological response
Polymer Journal, cilt.39, sa.1, ss.24-33, 2007 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 39 Sayı: 1
- Basım Tarihi: 2007
- Doi Numarası: 10.1295/polymj.pj2006048
- Dergi Adı: Polymer Journal
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Sayfa Sayıları: ss.24-33
- Anahtar Kelimeler: Electrorheological fluids, Molar mass, Poly(ε-caprolactone), Ring-Opening Polymerization (ROp), Shear stress
- Açık Arşiv Koleksiyonu: AVESİS Açık Erişim Koleksiyonu
- Ankara Hacı Bayram Veli Üniversitesi Adresli: Hayır
Özet
Electrorheological (ER) fluids are suspensions composed of ionomer solid particles dispersed in insulating liquids, which show abrupt changes of rheological properties under the stimulation of an external electric field. In this study, electrical and ER properties of end-chain and mid-chain functional macrophotoinitiators of poly-(ε-caprolactone) were investigated. For this purpose 4 different samples of poly(ε-caprolactone) were synthesized with different molar masses. They were then ground milled for a few hours to obtain micron size. The particle sizes of the poly(ε-caprolactone)s were determined by dynamic light scattering. Suspensions of poly(ε-caprolactone) s were prepared in silicone oil (SO), at a series of concentrations (c = 5-20%, m/m). The gravitational stability of suspensions against sedimentation was determined at constant temperature (T = 25°C). Flow times of the suspensions were measured under no electric field (E = 0 kV/mm), and under an external applied electric field (E ≠ 0 kV/mm) strengths and a strong ER activities were observed for all the poly(ε-caprolactone)s/SO suspensions. Further, the effects of suspension concentration, molar mass of the poly(ε- caprolactone)s, shear rate, electric field strength, frequency, promoter and temperature onto ER activities of suspensions were investigated. © 2006 The Society of Polymer Science, Japan.