Please look at the following below links which may help you in your analysis:

https://link.springer.com/referenceworkentry/10.1007%2F978-3-662-44324-8_349

https://www.tandfonline.com/doi/abs/10.1080/00986445.2017.1378647?src=recsys&journalCode=gcec20

https://www.omicsonline.org/preparation-characterization-and-gas-permeation-of-polyimide-mixed-matrix-membranes-2155-9589.1000101.pdf

Thanks

It is soluble in a wide variety of solvents. choose one depending on the nature of the impurity present in it.

Please look at the following below links which may help you in your analysis:

https://link.springer.com/referenceworkentry/10.1007%2F978-3-662-44324-8_349