Synthesis, Characterization and Properties of New Fluorinated Poly(imide siloxane) Co-polymers from 4,4′-(Hexafluoro-isopropylidene)diphthalic Anhydride

Abstract

Several new poly(imide siloxane)s co-polymers have been prepared by the reaction of 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) with commercially available 4,4′-oxydianiline (ODA) and with five different novel trifluoromethyl-substituted diamines, each with 20 wt% aminopropyl-terminated polydimethylsiloxane (APPS). The poly(imide siloxane)s are well characterized by different spectroscopic, thermal, mechanical and electrical techniques. The synthesized polymers exhibit good solubility in different organic solvents. The 1H-NMR indicates that the siloxane incorporation is about 17–19% for polymers 1a–f. These poly(imide siloxane) films show low water absorption rate (0.88–0.09%) and a low dielectric constant (2.43–2.58) at 1 MHz. The polymers show very good thermal stability, even up to 419°C for 5% weight loss in synthetic air and a glass transition temperature of up to 230°C. All poly(imide siloxane)s formed tough transparent films, with a tensile strength of up to 79 MPa, a modulus of elasticity of up to 1.38 GPa and elongation-at-break of up to 30%. Thermal, mechanical and dielectric properties of these polymers have been evaluated and compared with their non-siloxane analogues.