Novel soluble poly(ether imide)s with trifluoromethyl and chloride pendant groups for optical materials

Abstract

A new bis(ether dianhydride) monomer [4,4′-(2-(3′-trifluoromethyl-4′-chlorophenyl)-1,4-phenylenedioxy)-diphthalic anhydride (3)] was designed and prepared through a multistep reaction sequence. The new monomer 3 was polymerized with typical diamines, such as PDA, ODA, APB, 6FAPB and 9F–Cl-APB, using a two-step chemical imidization method to obtain the corresponding poly(ether imide)s (PEIs) (4a–4e). All the PEIs had high glass transition temperatures, excellent thermal stability, good solubility, and could be made into transparent and flexible films. The cast films showed UV-vis absorption edges at 346–369 nm, low birefringences of 0.0052–0.0131, low dielectric constants of 2.69–2.80, and low water uptakes of 0.30–0.52 wt%. Based on the characterization results, a series of optical materials with tunable refractive indices were obtained by copolymerization in the range of 1.6217–1.5523 at 650 nm.