کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5182563 1380992 2013 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Dynamic relaxation characteristics of thermally rearranged aromatic polyimides
ترجمه فارسی عنوان
ویژگی های آرامش دینامیکی پلییمید های معطر ترمودرید شده
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
چکیده انگلیسی

The glass-rubber and sub-glass relaxation characteristics of ortho-functionalized aromatic polyimides and thermally rearranged polymers were investigated by dynamic mechanical and dielectric methods. Soluble polyimides (HAB-6FDA; APAF-ODPA) were synthesized by chemical and thermal imidization and subject to thermal rearrangement at elevated temperature. For the thermal exposure histories investigated, mass loss studies indicated partial conversion of the polyimide precursor, suggesting the formation of TR copolymers containing both benzoxazole units and residual imide segments. Measurement of storage modulus and loss tangent was used to follow the thermal rearrangement process in-situ as reflected in the suppression of the polyimide glass transition as a function of precursor structure, the nature of the ortho functional groups and prior thermal exposure. In addition, changes in the position and intensity of local relaxations detected across the sub-glass temperature range were correlated with the degree of thermal rearrangement in these polymers.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 54, Issue 2, 24 January 2013, Pages 891-900
نویسندگان
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