Structure and properties of new highly soluble aromatic poly(etherimide)s containing isopropylidene groups

Abstract

A series of amorphous poly(etherimide)s (PEIs) was synthesized from 4,4 0 -(4,4 0 -isopropylidene-diphenoxy)bis(phthalic anhydride) and different diamines or from 4,4 0 -(4,4 0 -isopropylidene-diphenyl-1,1 0 -diyldioxy)dianiline and 4,4 0 -(hexafluoroisopropylidene)diphthalic anhydride. The structures of the obtained PEIs were confirmed by Fourier transform infrared spectroscopy (FTIR), 1 H and 13 C nuclear magnetic resonance spectroscopies ( 1 H and 13 C NMR) and by elemental analysis. These polymers show excellent solubility in a broad range of solvents and produce strong and flexible films. The films were examined using differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), wide-angle X-ray diffraction (WAXD) and mechanical testing, and were characterized by gas transport measurements. The obtained films exhibit thermal stability up to 500 1C, good mechanical properties and a CO 2 permeability of 7.85 Barrer with a CO 2 /N 2 selectivity of 21.2 for the polymer that contains hexafluoroisopropylidene moieties. The effects of the chemical structures on the physical and gas permeation properties were studied. The introduction of bulky cardo or hexafluoroisopropylidene moieties into the polymer chain increases the glass transition temperature (T g ) and fractional free volume (FFV), while the incorporation of additional ether linkages produces the opposite effect. Using an existing free volume approach, we found that the permeabilities of the studied PEIs are well correlated with their FFVs. Polymer Journal (2013) 45, 1202-1209; doi:10.1038/pj.2013.49; published online 22 May 2013 Keywords: gas transport properties; poly(etherimide)s; polyimides; thermal properties INTRODUCTION Aromatic polyimides (PIs) were first produced in 1908; since then, interest in this type of polymers has been growing because of their exceptional properties, such as excellent thermal, thermo-oxidative and dimensional stability; high radiation and solvent resistance; low dielectric constant; and unusually good mechanical properties. [1][2][3] This unique combination of properties makes PIs ideal for a variety of applications, for example, in microelectronics, microelectromechanical systems, aerospace and photoelectronics or as gas separation membranes, materials for memory devices, alignment layers in liquid crystal displays, and redox-active, electrochromic polymers. 3-6 Although many excellent polyimides are known and commercially available, new polyimides are emerging as research continues on the chemical structure-property correlations and on the search for new compounds with unique combinations of properties for special applications. Recently, particular attention has been paid to new materials and technologies for gas separation applications because of environmental concerns and economic interests. Polymeric gas separation membranes exhibit good mechanical properties, often

Synthesis and thermal, mechanical and gas permeation properties of aromatic polyimides containing different linkage groups

“…However, they are not the only factors controlling gas permeation, and their usefulness in drawing more general relationships between structure and permeation properties is limited. This is in accordance with our earlier conclusions and with other literature data …”

Thermal, Electrical, and Gas Transport Properties of New Aromatic Poly(Ether Ether Ketone)/Silica Hybrid Films

“…All the polymers investigated show the following order of decreasing gas permeability, He > CO 2 > O 2 > N 2 , demonstrated by the majority of glassy polymers, for example, polyimides, the properties of which were reported recently . This behavior is in accordance with the sequence of increasing kinetic diameter of gas molecules (He, 2.60 Å; CO 2 , 3.30 Å; O 2 , 3.46 Å; N 2 , 3.64 Å, ).…”

Nafion‐115/aromatic poly(etherimide) with isopropylidene groups/imidazole membranes for polymer fuel cells

“…FT‐IR spectrum of Nafion‐115/PI membrane showed peak at 1684 cm −1 shifted to higher wavenumber in comparison to pure Nafion‐115 membrane (1630 cm −1 related to S‐OH groups). Moreover, absorption bands characteristic from the asymmetric and symmetric stretching vibration of the carbonyl group in the imide ring of PI at 1784 and 1725 cm −1 , respectively, in membrane are shifted to lower wavenumber (Figure ). This is an effect of hydrogen bonding interactions between PI and Nafion‐115 as schematically is presented in Figure .…”

“…Aromatic poly(etherimide) with isopropylidene groups (PI) was obtained from 4,4′‐(hexafluoroisopropylidene) diphthalic anhydride and 4,4′‐(4,4′‐isopropylidene‐diphenyl‐1,1′‐diyldioxy)dianiline in NMP solution according to the synthesis described in Ref. .…”