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Title: Role of Grafting Density and Nitrile Functionalization on Gas Transport in Polymers with Side-Chain Porosity
This study details the enhancement of CO2 selectivity in ring opening metathesis polymerization (ROMP) polymers that contain nitrile moieties and micro-pore generating ladder side chains. A material, CN-ROMP homopolymer, with nitriles in the ladder side chains was originally targeted and synthesized, however its low molecular weight and backbone rigidity precluded film formation. As a result, an alternative method was pursued wherein copolymers were synthesized using norbornene (N) and nitrile norbornene (NN). Herein, we report an investigation of the structure–property relationships of backbone functionalization and grafting density on the CO2 transport properties in these ROMP polymers. Nitrile-containing copolymers showed an increase in CO2/CH4 sorption selectivity and a concomitant increase in CO2/CH4 permselectivity when compared to the unfunctionalized (nitrile free) analogs. The stability in CO2 rich environments is enhanced as grafting density of the rigid, pore-generating side chains increases and an apparent tunability of CO2 plasticization pressure was observed as a function of norbornene content. Lower loadings of norbornene resulted in higher plasticization pressure points. Gas permeability in the ROMP copolymers was found to correlate most strongly with the concentration of ladder macromonomers in the polymer chain.  more » « less
Award ID(s):
2207299
PAR ID:
10517322
Author(s) / Creator(s):
; ; ; ; ;
Publisher / Repository:
American Chemical Society
Date Published:
Journal Name:
Macromolecules
Volume:
57
Issue:
5
ISSN:
0024-9297
Page Range / eLocation ID:
2458 to 2467
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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