Synthesis and Properties of Novel Fluorinated Poly(phenylene‐co‐imide)s

Abstract

A new class of high‐performance materials, fluorinated poly(phenylene‐co‐imide)s, were prepared by Ni(0)‐catalytic coupling of 2,5‐dichlorobenzophenone with fluorinated dichlorophthalimide. The synthesized copolymers have high molecular weights ($\overline M _{\rm w}$ = 5.74 × 104–17.3 × 104 g · mol−1), and a combination of desirable properties such as high solubility in common organic solvent, film‐forming ability, and excellent mechanical properties. The glass transition temperature (Tgs) of the copolymers was readily tuned to be between 219 and 354 °C via systematic variation of the ratio of the two comonomers. The tough polymer films, obtained by casting from solution, had tensile strength, elongation at break, and tensile modulus values in the range of 66.7–266 MPa, 2.7–13.5%, and 3.13–4.09 GPa, respectively. The oxygen permeability coefficients ($P_{{\rm O}_{\rm 2} }$) and permeability selectivity of oxygen to nitrogen ($P_{{\rm O}_{\rm 2} } /P_{{\rm N}_{\rm 2} }$) of these copolymer membranes were in the range of 0.78–3.01 barrer [1 barrer = 10−10 cm3 (STP) cm/(cm2 · s · cmHg)] and 5.09–6.25, respectively. Consequently, these materials have shown promise as engineering plastics and gas‐separation membrane materials.

Correlation between Cohesive Energy Density, Fractional Free Volume, and Gas Transport Properties of Poly(ethylene-co-vinyl acetate) Materials

“…In many works, the validity of these equations in describing and predicting gas transport properties of polymers has been investigated. There are studies showing that FFV correlates reasonably well with and of polymers [5][6][7][8]. When larger discrepancies between experimental results and theory were obtained, errors in FFV estimation or differences in FFV distribution across materials, which are not taken into account in (1) and (2), have been proposed as a possible explanation [9].…”

“…Equations (4), (6), and (7) are generally accepted as a first approximation of transport parameters in semicrystalline polymers [4], if any data concerning impedance factors are available. In this work, (6) and (7) have been applied to correlate permeability and diffusivity constants, and the validity of using them seems to be legitimate due to a very low volume fraction of crystallites in the EVA materials studied.…”