Synthesis and Properties of Cost-Effective Light-Color and Highly Transparent Polyimide Films from Fluorine-Containing Tetralin Dianhydride and Aromatic Diamines

Abstract

A novel fluoro-containing tetralin dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-6-fluoro-1-naphthalene succinic dianhydride (FTDA) was successfully prepared via a cost-effective route with maleic anhydride and p-fluorostyrene as the starting materials. A series of semi-alicyclic polyimides (PIs) have been synthesized from FTDA and aromatic diamines, including 4,4'-oxydianiline (ODA) for PI-a, 1,4-bis(4-aminophenoxy)benzene (APB) for PI-b, 2,2'-bis[(4-aminophenoxy)phenyl]propane (BAPP) for PI-c, and 2,2'-bis[(4-aminophenoxy)- phenyl]hexafluoropropane (BDAF) for PI-d via a one-step high-temperature imidization procedure. The derived PI resins are easily soluble in polar aprotic solvents, such as N-methyl-2-pyrrolidone (NMP) and N,N-dimethylacetamide (DMAc). Flexible and tough PI films were cast from their solutions in NMP at a solid content of 15 wt%. The prepared PI films exhibited good optical transparency in the visible light region with the transmittance higher than 80% at the wavelength of 450 nm. In addition, the PI films exhibited good thermal stability with the 5% weight loss temperatures >402 ^oC and glass transition temperatures >230 ^oC.