Biobased transparent polyimides with excellent solubility and mechanical properties using myo-inositol derived diamines

Here, we develope a kind of biobased transparent polyimides (PIs) with excellent solubility and mechanical properties by using myo-inositol derived diamines. Two biobased diamines M1 and M2 were synthesized through a protection reaction of –OH units of myo-inositol followed by the substitution and subsequent reduction reactions. Myo-inositol based PIs were prepared via the microwave-assisted polymerization of biobased diamines and commercial dianhydrides. These PIs were soluble in various common solvents even in CH 2 Cl 2 and acetone at room temperature . The biobased PIs also showed good optical transparency with T 450nm values of over 82%. Moreover, all the PI films possessed outstanding mechanical properties with tensile modulus of over 3.5 GPa, which was higher than that of most of petroleum-based PIs. In addition, the PI films containing –OH units were obtained via a simple deprotection reaction of myo-inositol based PIs.