Polymers of Intrinsic Microporosity (PIMs)

Easily processed molecular sieves

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.

Development Status

  • 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).

IP Status

  • 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

Commercial Offerings

  • 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.

Technology overview

  • 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.



Please note, the header image is purely illustrative. Source: D3Damon via GettyImages

Quote: TEC1103421

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Dr Maria Lopalco

Technology Transfer Manager
School of Chemistry
The Institute of Genetics and Cancer