Biobased Polyimides from 4-Aminocinnamic Acid Photodimer

The development of high-performance biobased polymers such as polyimides (PIs) is indispensable to establish a sustainable green society, but it is very difficult due to the incompatibility of their monomeric aromatic diamines with microorganisms. Here, we developed biobased PIs from bioavailable aromatic diamines, which were photodimers of 4-aminocinnamic acid (4ACA) derived from genetically manipulated Escherichia coli. These biobased PI films showed ultrahigh thermal resistance with T10 values over 425 °C and no Tg values under 350 °C, which is the highest value of all biobased plastics reported thus far. The PI films also showed high tensile strength, high Young's moduli, good cell compatibility, excellent transparency, and high refractive indices.