Synthesis and Characterization of Bisphenol F-Type Polyimides

Bisphenol F (BPF) and bisphenol F dianhydride (BPFDA) were synthesized from phenol and formaldehyde. Then, BPFDA reacted with m-phenylenediamine (m-PDA), 4,4′-oxydianiline (4,4′-ODA ) and 1,4bis(4-aminophenoxy) benzene (TPEQ), respectively, to give three polyimides. The structure, solubility, thermal stability and mechanical properties of these polymers were characterized. Results show that the obtained polyimides with inherent viscosities of 0.5—0.6 dL/g exhibit high molecular weight and have excellent solubility. They dissolve not only in polar aprotic solvents such as NMP, DMAc, DMF, but also in nonpolar solvents such as CHCl3. The glasstransition temperature (Tg) of these three polyimides are around 200 °C. Degradations for 5% weight loss (T5%) are all above 440 °C in nitrogen. Tensile strength, Young's modulus and elongation at break of the obtained polymide films are about 100 MPa, 3 GPa and 7%, respectively. They exhibit good mechanical properties.