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In a paint stripping formulation, the main ingredient is the active solvent able to diffuse in the reticulated film and to break the adhesive bonds between film and substrate. Thanks
to its low molecular volume and high polarity, DMSO is a choice solvent to formulate efficient paint stripper.
The addition of other components in the paint stripping formulation will help to adjust performances:
Co-solvent
All protic or polar solvents have a high cohesion energy due to the large number of hydrogen or dipolar bonds present in the solution. This "group" energy constitutes
an obstacle to the penetration of molecules into the film. The addition of a non-protic co-solvent of medium polarity will facilitate the diffusion within the film by reducing this energy.
Figure 1: Behavior of a polar solvent
(a): In absence of co-solvent (b): In presence of co-solvent
When formulating DMSO-based
paint stripper, the following family of co-solvents can be used: ketones (methylethylketone - MEK, methylisobutylketone - MIBK, ethylamylketone - EAK, etc.), ethers, esthers and green solvents.
Activators
The activators are small & very polar molecules which will help in breaking the adhesive bonds between the paint film and the substrate. They show a strong affinity
towards polar surfaces (wood, metal, glass).
Thickeners
It is preferable to use cellulosic thickeners such as hydroxypropylcellulose soluble in any polar organic solvents.
Evaporation retardants
When using volatil co-solvents, it is preferable and even absolutely necessary to use an evaporation retardant (MEK for example).
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