Abstract:In this work, a series of polyimides were synthesized in m-cresol by one-step condensation polymerization with diamine monomer m-xylylenediamine (MXDA) and five aromatic dianhydride monomers 4,4'-oxydiphthalic anhydride (ODPA), 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA), and 4,4'-(4,4'-isopropylidene diphenoxy) bis(phthalic anhydride) (BPADA). The structures and properties of the polymers were characterized by FTIR, 1HNMR, DSC, TGA, UV-Vis spectrophotometer, etc. The results show that Inherent viscosity number of PIs are 0.36~1.44 dL/g and all the PIs have good solubility in phenolic solvents. The glass transition temperatures (Tg) and the 5% thermal weight loss temperature of the PIs are 184~243 ℃ and 485~538 ℃, respectively, which implies that they have excellent thermal properties. Furthermore, the transmittances of the PI films are 24%~85% at 400 nm and 69%~88% at 500 nm, and the cutoff wavelengths are in the range of 308~367 nm, demonstrating the good optical properties of these polymers. The tensile strength, young's modulus and elongation at break of PIs are 41.1~85.3 MPa, 1.7~2.1 GPa and 2.5~8.7%, respectively, indicating that the PIs have good mechanical properties .