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A polyimide(PI) derived from asymmetric 2,3,3,4-biphenyltetracarboxylic dianhydride(a-BPDA) and 4,4-oxydianiline (4,4-ODA) exhibits a higher Tg than that of symmetric PI(s-BPDA/4,4-ODA) and exhibits a large drop in the storage modulus, E above the Tgl).This is attributed to the decrease in the intermolecular interactions of the geometrically irregular PI (a-BPDA/4, 4-ODA) molecules in addition to restriction of free rotation around biphenyl imides linkages.