Elucidating the Molecular Mechanisms by which Porous Polymer Networks Affect Structure, Aging Propensity, and Selectivity of Microporous Glassy Polymer Membranes using a Multiscale Approach.

Microporous glassy polymer membranes suffer from physical aging, which adversely affects their performance in the short time frame. We show that the aging propensity of a model microporous polymer, poly(1-trimethylsilyl-1-propyne) (PTMSP), can be effectively mitigated by blending with as little as 5 wt % porous polymer network (PPN) composed of triptycene and isatin. The aging behavior of these materials was monitored via N pure gas permeability measurements over the course of 3 weeks, showing a 14% decline in PTMSP blended with 5 wt % PPN vs a 41% decline in neat PTMSP.

Mixed Matrix Membranes Using Porous Organic Polymers (POPs)-Influence of Textural Properties on CO/CH Separation.

Mixed matrix membranes (MMMs) provide the opportunity to test new porous materials in challenging applications. A series of low-cost porous organic polymer (POPs) networks, possessing tunable porosity and high CO uptake, has been obtained by aromatic electrophilic substitution reactions of biphenyl, 9,10-dihydro-9,10-dimethyl-9,10-ethanoanthracene (DMDHA), triptycene and 1,3,5-triphenylbenzene (135TPB) with dimethoxymethane (DMM). These materials have been characterized by FTIR, C NMR, WAXD, TGA, SEM, and CO uptake.

Isomeric Aromatic Polyimides Containing Biphenyl Moieties for Gas Separation Applications.

An optimized synthesis of the monomer 2,2'3,3'-biphenyltetracarboxylic dianhydride, iBPDA, was performed to obtain high molecular weight polymers. This monomer has a contorted structure that produces a non-linear shape, hindering the packing of the polymer chain. Aromatic polyimides of high molecular weight were obtained by reaction with the commercial diamine 2,2-bis(4-aminophenyl) hexafluoropropane, 6FpDA, which is a very common monomer in gas separation applications.