Colorless shape memory polyimide (CSMPI) has potential applications in broad fields, especially in advanced optoelectronics due to the excellent optical transparency, shape memory effect and high temperature resistance. In this work, CSMPI prepared by high flexible dianhydrides and fluorine-containing diamines has excellent optical transparency, shape memory properties and high temperature resistance. High flexible dianhydrides that makes the molecule chains more easily twisted and tangled to form physical crosslinking points is favorable for possessing great shape memory property. The fluorine-containing diamines effectively destroyed the highly conjugated molecular structure and inhibited the formation of CTC, ensuring the CSMPI with excellent optical transparency. The effects of monomer ratio and imidization temperature on the molecular structure and properties were discussed. The CSMPI film possesses a higher glass transition temperature (Tg) of 234 °C, compared to the reported transparent shape memory polymers (SMPs). Most importantly, the transmittance of CSMPI film is 87~90% at 450~800nm, meeting the requirements of heat resistance and transmittance of the substrate. Both shape recovery and shape fixity are over 97%. Flexible and colorless CSMPI films has potential applications in broad fields, especially in advanced optoelectronics, such as flexible substrates for OLED and OPV devices, etc.
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