Synthesis and properties of transparent poly(ester-amide-imide)s from tert-butylhydroquinone bis(trimellitate anhydride) and p-phthaloyl chloride

Two series of poly(ester-amide-imide)s (PEsAIs) with simultaneously bulky side groups, ester and amide bonds were synthesized by copolymerization of tert -butylhydroquinone bis(trimellitate anhydride), p -phthaloyl chloride and other monomers. These PEsAIs had glass transition temperatures ( T g s) in the range of 231–301 °C, coefficients of thermal expansion (CTEs) of 17–59 ppm K −1 and displayed good mechanical properties with tensile modulus of 2.6–4.5 GPa, tensile strengths of 63–143 MPa and elongations at break of 3.0%–11.7%. All films had good transparency with transmittances at 400 nm ( T 400nm ) of 43%–80%. The introduction of p -phthaloyl chloride successfully improved the properties of the polymer with higher transmittance, higher T g and lower CTE. In particular, PEsAI-b-60 presented the best comprehensive performance with a moderate T g of 301 °C, low CTE of 17 ppm K −1 and high transmittance ( T 400nm ) of 75%. © 2023 Society of Industrial Chemistry.