DCM and DMF and other solvent like THF are toxic to human body but these are used as solvent of PLA and which is used in food application.
Thak you Mr. Gruen.
But how can we use DCM and DMF to dissolve PLA. Those are toxic solvents.
You can take a look at for example US7311980, where a mixture of trichloroethane (TCE)) and chloroform is used to dissolve PLA. The patent teaches that the solvent is then evaporated off in a 50 degC oven for 1 hr (for example). I am assuming that since the concentration of PLA is so low, that the coating is quite thin, and therefore evaporation of most of the solvents is quite facile (and there is probably a requirement to demonstrate how much residual solvent remains on a coating, for example by dissolving the coating with another solvent, and then detecting by some chromatography how much of the TCE and chloroform was in the coating.
Perhaps a similar argument will apply for DCM, DMF, or THF.
https://www.google.com/patents/US7311980
- Badges
- Science topic