Novel soluble fluorinated poly(ether imide)s with different pendant groups: Synthesis, thermal, dielectric, and optical properties

Abstract

AbstractThree types of new bis(ether dianhydride) monomers, [4,4′‐(2‐(3′‐methylphenyl)‐1,4‐phenylenedioxy)‐diphthalic anhydride (4a)], [4,4′‐(2‐(3′‐trifluoromethylphenyl)‐1,4‐phenylenedioxy)‐diphthalic anhydride (4b)], and [4,4′‐(2‐(3′,5′‐ditrifluoromethylphenyl)‐1,4‐phenylenedioxy)‐diphthalic anhydride (4c)] were prepared via a multistep reaction sequence. Three series of soluble poly(ether imide)s (PEIs) were prepared from the obtained dianhydrides by a two‐step chemical imidization method. Experimental results indicated that all the PEIs had glass transition temperature in the range of 200–230 °C and the temperature of 5% weight loss in the range of 520–590 °C under nitrogen. The PEIs showed excellent solubility in a variety of organic solvents due to introduction of the bulky pendant groups and were capable of forming tough films. The casting films of PEIs (80–91 μm in thickness) had tensile strengths in the range from 88 to 117 MPa, tensile modulus from 2.14 to 2.47 GPa, and elongation at break from 15 to 27%. The casting films showed UV‐Vis absorption edges at 357–377 nm, low dielectric constants of 2.73–2.82, and water uptakes lower than 0.66 wt %. The spin‐coated films of PEIs presented a minimum birefringence value as low as 0.0122 at 650 nm and low optical absorption at the optical communication wavelengths of 1310 and 1550 nm. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3281–3289, 2010