Authors: M Saeed Butt Zareen Akhter M ZafaruzZaman Humaira Masood Siddiqi
Publish Date: 2008/08/22
Volume: 286, Issue: 12, Pages: 1455-1461
Abstract
The diamine 4aminophenyloxyN44amiophenyloxybenzylideneaniline was prepared via the nucleophilic substitution reaction and was polymerized with different dianhydrides either by onestep solution polymerization reaction or twostep procedure The latter includes ringopening polyaddition to give polyamic acid followed by cyclodehydration to polyimides The inherent viscosity ranges from 061–079 dl/g Some of the polymers were soluble in most of the organic solvents such as DMSO DMF DMAc NMP and mcresol even at room temperature The degradation temperature of the resultant polymers falls in the ranges from 240–500 °C in nitrogen with only 10 weight loss Specific heat capacity at 200 °C ranges from 10929–26275 J g−1 k−1 The temperature at which the maximum degradation of the polymer occurs ranges from 600–630 °C The glass transition temperature Tg values of the polyimides ranged from 185 to 272 °C The activation energy and enthalpy of the polyimides ranged from 475–550 kJ/mole and 457–530 kJ/mole and the moisture absorption in the range of 023–072
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