Polymers of Intrinsic Microporosity (PIMs) are a relatively new class of macromolecule, with unique structural features that give rise to a number of distinct properties, including the combination of solution-processability and microporosity.
- Potential applications in the fabrication of selectively permeable membranes for gas separation, sensors and adsorbents.
- Researchers at the University of Edinburgh have developed methods for preparing PIMs using step-growth polymerisations, based on reactions that provide non-linear linking groups based on Tröger’s base (TB).
- Method for producing polymers comprising multiple repeat units of bicyclic diamines: US 9,018,270B and EP 2616493B
- Polymers, their method of manufacture and use thereof: US 9,862,801B and EP 11761110.3A
- Technology available for licensing
The technology of polymerisation using Tröger’s base formation allows the ready formation of step-growth polymers, which have unusual combinations of physical properties, from a single diamine monomer.
- Polymer rigidity and fixed chain conformation result in solution-processable materials with very high glass transition temperatures.
- Solids possess large amounts of free volume, which is freely accessible to smaller gas molecules via diffusion but high rigidity reduces transport of larger molecules producing high size selectivity.
Figure: Tröger’s base formation can be used to make high molecular mass, solution-processable polymers that act as microporous molecular sieves for membrane separations
- Microporosity due to highly rigid structures: high free volume
- Freely soluble in organic solvents at ambient temperatures enabling processing into a variety of membranes, fibres and objects.
- Glass transition temperature >350°C
Polymers of Intrinsic Microporosity (PIMs), McKeown N B., Polymer 2020, 202: 122736.
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