کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5203736 | 1381938 | 2008 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Liquid crystalline and photoactive poly[4,4â²-stilbeneoxy]alkylbiphenylphosphates
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Liquid crystalline and photoactive poly[4,4â²-stilbeneoxy]alkylbiphenylphosphates Liquid crystalline and photoactive poly[4,4â²-stilbeneoxy]alkylbiphenylphosphates](/preview/png/5203736.png)
چکیده انگلیسی
A series of liquid crystalline and photoactive polymers were synthesized from biphenylphosphorodichloridate with various 4,4â²-bis(m-hydroxyalkyloxy)stilbenes (m = 2, 4, 6, 8, 10) in chloroform by solution polycondensation method using an acid scavenger. The resultant polymers were characterized by inherent viscosity, FT-IR, 1H, 13C and 31P NMR spectroscopies. The liquid crystalline (LC) properties were studied using HOPM and DSC and it was inferred that out of the five polymers synthesized, higher methylene chain containing polymers (m = 6, 8, 10) exhibited LC properties. Thermogravimetric analysis revealed that all the polymers were stable in between 290 and 367 °C and underwent degradation thereafter. The thermal stability and char yield of the polymers decreased with increase in flexible methylene chain. The photochemical properties of these polymers were investigated by UV and fluorescence spectroscopy. Crosslinking proceeds via 2Ï-2Ï cycloaddition reaction of the -CHCH- of the stilbene moieties. The rate of crosslinking increases with increase in methylene chain length in the polymer backbone. The fluorescence spectra showed that the longer methylene spacer containing polymers exhibited larger red-shifts than the shorter spacer containing polymers.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer Degradation and Stability - Volume 93, Issue 8, August 2008, Pages 1564-1570
Journal: Polymer Degradation and Stability - Volume 93, Issue 8, August 2008, Pages 1564-1570
نویسندگان
A. Ravikrishnan, P. Sudhakara, P. Kannan,