کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5187887 | 1381140 | 2008 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Synthesis and photochromic behavior of new polyimides containing azobenzene side groups
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موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Aromatic polyimides containing side azobenzene groups have been synthesized by low-temperature solution polycondensation of certain aromatic dianhydrides with aromatic diamines containing preformed side azobenzene groups followed by chemical imidization at 100 °C in the presence of pyridine and acetic anhydride. The weight average molecular weight of these polymers is in the range of 16,000-129,000. The glass transition temperature of these polyimides is in the range of 185-230 °C. The polymer architecture presents a special characteristic, one of the azobenzene aromatic units being in the main chain of the polymer. This situation is intermediary between main-chain and side-chain azobenzene-containing polymers. The photochromic behavior, determined by the trans-cis isomerization process of azo-groups, in solution and in solid state, was evaluated. The synthesized polyimides were studied by spectral methods (UV, IR), thermal analysis and molecular modeling. A preliminary study concerning the surface structuration capacity of the polyimides was accomplished. Good results were obtained using Nd:YAG laser at 355 nm, at an incident fluence of 35 mJ/cm2 (situated below the laser ablation limit).
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 49, Issue 6, 17 March 2008, Pages 1475-1482
Journal: Polymer - Volume 49, Issue 6, 17 March 2008, Pages 1475-1482
نویسندگان
Ion Sava, Ana-Maria Resmerita, Gabriela Lisa, Victor Damian, Nicolae Hurduc,