
Keywords: چرخش قطبی زاویه جادویی زاویه چرخش; TR polymers; Polybenzoxazoles; Gas separation membranes; PI; poly(hydroxyimide); PA; poly(hydroxyamide); PBO; polybenzoxazole; TGA; thermogravimetric analysis; DSC; differential scanning calorimetry; PALS; positron annihilation lifetime spectroscopy; FTIR