Exploring Polymers of Intrinsic Microporosity – Microporous, Soluble Polyamide and Polyimide

Abstract

Polyamides and polyimides featuring a spirobifluorene unit as a structure directing motif in the polymer chain show intrinsic microporosity and consequently high surface areas. Such a spirobifluorene generates a 90° kink per repeating unit and thus prevents space‐efficient packing or crystallization of the otherwise stiff polymer chains. Thus, the approach presented here extends the concept of polymers of intrinsic microporosity for ladder type poly(dibenzodioxane)s to more common polymers of high commercial interest. For example, a microporous polyimide with a surface area of ≈550 m2 · g−1 was produced, which is readily soluble in chloroform.magnified image

Controlled thermal oxidative crosslinking of polymers of intrinsic microporosity towards tunable molecular sieve membranes

“…1e. Such a gate-opening phenomenon indicates the complicated molecular interactions at low temperature (77 K), and although it has been reported in other works, it is not well understood for PIM-1 and other high free volume polymers 38,39 . Gas sorption properties of CO 2 , CH 4 and N 2 were also measured at 273 K (Fig.…”

Gas permeation and physical aging properties of iptycene diamine-based microporous polyimides

“…One class of PIMs is based on high-free-volume aromatic polyimides (PIM-PIs) that contain rigid contortion sites either in their dianhydride and/or diamine moiety. Examples of such molecular building blocks are: (i) spirobisindane dianhydrides [7,12,13] and diamines [14,15], ethanoanthracene dianhydride [6,16], spirobifluororene dianhydride [17] and diamines [18,19], Tröger's base diamines [20][21][22], and triptycene dianhydrides [10,23] and diamines [15,24,25].…”

Trends and challenges for microporous polymers

“…A large number of cationic microporous polymers are composed of iminium linkages and in some cases can be of crystalline structure due to a reversible condensation bondforming process. By condensation of a charged ethidium bromide building block Zhu et al synthesized a cationic covalent organic framework EB-COF-X (X: counter anion), 196 which after anion exchange with poyloxometallate (POM) anions PW 12 O 40 3À exhibited high proton conductivities of 3.32 Â 10 À3 Sc m À1 with a relative humidity of 97% making it comparable if not better than many of the proton conducting MOFs (Fig. 13).…”

“…Synthetic protocols which can be used for the generation of microporous polymers are highly diverse and range from metalcatalyzed or -mediated (Sonogashira, 4,5 Suzuki, 6 Yamamoto, 7 Buchwald-Hartwig, 8 Eglinton, 9 Heck 10 ) to click-type reactions, 11 acid or base-catalyzed polycondensation reactions (formation of polyamides, 12 -imides, [13][14][15] -benzimidazoles, 16,17 -dioxanes, 18 -boroxines and boronate esters, 19 -imines 20 -aminals, 22 azo-bridged compounds [23][24][25] and many others [26][27][28][29] The great variety of synthesis conditions not only allows the usage of differentially functionalized monomers, but much more importantly to find appropriate reaction conditions tolerating any given functional group which is planned to be introduced into the network, i.e. synthesis can be carried out with high chemical orthogonality.…”