Table 2 Hansen solubility parameters for various solvents and the calculated PEI-solvent distance [17]
Compound | δh (MPa)1/2 | δd (MPa)1/2 | δp (MPa)1/2 | δ(solvent–PEI) (MPa)1/2 |
|---|---|---|---|---|
Polyetherimide (PEI) | 6.4 | 17.7 | 6.0 | – |
n-Methylpyrrolidone (NMP) | 7.2 | 18.4 | 12.3 | 6.39 |
Methyl l-lactate (ML) | 10.2 | 15.8 | 6.5 | 4.28 |
Ethyl lactate (EL) | 12.5 | 16.0 | 7.6 | 6.53 |
Propylene carbonate (PC) | 4.1 | 20.0 | 18.0 | 12.43 |
Tributyl o-acetylcitrate (ATBC) | 6.2 | 15.4 | 4.1 | 2.99 |
Tributyl citrate (TBC) | 10.1 | 16.6 | 3.8 | 4.44 |
Triethyl phosphate (TEP) | 9.2 | 16.8 | 11.5 | 6.24 |
γ-Butyrolactone (γ-BL) | 7.4 | 19.0 | 16.6 | 10.73 |