کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5190259 1381201 2006 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Structure-property relationships in novel poly(imide-amide)-poly(ethylene glycol) hybrid networks
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Structure-property relationships in novel poly(imide-amide)-poly(ethylene glycol) hybrid networks
چکیده انگلیسی
Broadband dielectric relaxation spectroscopy (DRS), thermally stimulated depolarisation currents (TSDC), differential scanning calorimetry (DSC) and to a lesser extent water uptake measurements, were employed to investigate molecular mobility, morphology and crystallization/melting events of PEG in poly(imide-amide)-polyethylene glycol hybrid networks (PIA-PEG) with short (Mn=1000 g/mol) and long (Mn=3400 g/mol) PEG crosslinks. The results obtained suggest long range connectivity of the PEG component in the hybrids with short PEG crosslinks at PEG content higher than 40 wt% and in these with long PEG crosslinks at PEG content higher than 20 wt%. Crystallization of the PEG component is observed by DSC in the hybrids with the longer crosslinks at sufficiently high content of PEG, only. The glass transition temperature, Tg, of PEG component in the hybrids with the shorter PEG crosslinks is shifted to higher temperatures compared to that of the hybrids with longer PEG crosslinks, while suppression of the glass transition of the PEG component is observed in the hybrids with the shorter PEG crosslinks at PEG content lower than 40 wt%. The results are discussed in terms of constraints to segmental motion of the PEG crosslinks, imposed by fixed PEG chain ends on the rigid PI chains.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 47, Issue 1, 3 January 2006, Pages 357-366
نویسندگان
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