I was concerned about another post that said the Sylgard 184 that everyone is recoating their vats with is incompatible with IPA. Since I lightly rinse the PDMS with IPA in order to get the remaining resin out of the pdms layer when cleaning the tank, I did a check on the compatibility of Sylgard 184 with IPA:
Here is the result:
1.5.3 Chemical compatibility of PDMS
PDMS can be used mostly for water based solvent systems; organic solvents like chloroform, ether, THF etc. will diffuse into PDMS and swell it. Lee et al. have conducted a thorough study of PDMS compatibility with various solvents.
According to their study:
• PDMS is not swelled in nitromethane, DMSO, ethylene glycol, glycerol and water.
• PDMS is very slightly swelled (~5% or less) in dimethyl carbonate, acetone, pyridine, NMP, acetonitrile, phenol, ethanol, propylene alcohol and methanol.
• PDMS is extensively swelled (5-30%) in ethyl acetate, benzene, chloroform, 2-butanone, chlorobenzene, DCM, dioxane, propanol and tert-butyl alcohol.
• PDMS is severely swelled (>30%) in pentane, hexane, heptane, triethyl amine, ether, cyclohexane, xylene, toluene and THF.
• The most swelling solvent is diisopropylamine, which cause a linear expansion of PDMS 2.13 times. In acids and bases PDMS generally does not swell, unless it is dissolved by concentrated acids like 18M sulfuric acid or 100% trifluroacetic acid. But swelling can be also used to extract unbound PDMS strands from an elastomeric network; after such an extraction PDMS exhibits much better surface stability when plasma oxidized (the return of hydrophobicity is considerably slower).
Since IPA is a variant of propanol, this may be a valid concern.
My question: Are any of the solvents that do not swell the pdms – such as ethylene glycol- or acetone - also good as a solvent for the resin?