Synthesis of a Novel C60-Containing Polyimide: A New ‘Charm-Bracelet’ Type of Polyimide and Copolyimide

Abstract

The fullerene-containing polyimides were synthesized by the reaction of diamines and C60-containing dianhydride 2 and copolyimides were synthesized by the reaction of 2, 4, 4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and 4, 4′-diaminodiphenyl ether (ODA). Polyamic acids 3a, b and copolyamic acids 8b–e were soluble in polar aprotic solvents such as DMAc, DMF, DMSO and NMP, whereas 8b–e showed additional solubility in THF. The molecular weights of polyamic acids 3a, b and copolyimides 9b−e determined by gel permeation chromatography were in the range of 1.0 × 10 4−7.8 × 103 and 5 × 104−2.8 × 104 mol g−1, respectively. Polyamic acid 3a ;b contained other lower molecular weight oligomers. TGA results for polyimides and copolyimides showed thermal stability and the 10% weight loss temperatures were in the range of 430–520 °. Distinct glass transition temperatures of C 6′-containing polyimides were not observed by DSC measurement. The cyclic voltammograms of 2 and 3a indicated four reduction waves corresponding to C60 redox reactions, but the polyamic acid 8e showed one reduction wave at −1.39 V.