The solvent properties of DMSO are important in the synthesis of chemically resistant polymers and engineering resins.
DMSO is a powerful solvent for dissolving difficult monomers and will retain high molecular weight polymers in solution. This allows for the production of highly solvent resistant engineering resins.
Applications: Polysulfones are commonly prepared from a bis-(p-halophenyl) sulfone and a dihydric compound, such as bisphenol A, in a dipolar aprotic solvent such as Dimethyl Sulfoxide.
While many solvents may compete in the large category of polymer synthesis, DMSO comes into its own regarding high temperature engineering resins such as polysulfones (PES, PS), polyaryletherketones (PEK, PEEK, PEKK).
Because DMSO can dissolve many polymers at high loading levels, it can be used to produce finished products. This includes the use of DMSO to produce membranes and fibers. As a polymer processing solvent, DMSO is used in several ways.
- Membrane Manufacture: Ultrafiltration (UF) membranes are solvent-cast from DMSO, as are membranes used in fuel cell technology. Resins such as polysulfone (PS) are dissolved in DMSO and then cast into porous membranes using an antisolvent, or humidity.
- Carbon Fiber Technology: Relies on use of DMSO as a processing solvent. DMSO is of great value in spinning polyacrylonitrile (PAN) fibers, a precursor to carbon fiber. Dimethyl sulfoxide is used both in the spinning dope and in the coagulation bath.
- Polymer Dispersions: Polyurethanes synthesized in DMSO may be dispersed in water, similar to the use of other dipolar aprotic solvents in the manufacture of water-borne coatings. DMSO offers not only performance, but is a safer than alternatives like DMF and NMP.
DMSO offers not only performance, but is a safer solvent than the alternatives DMF, NMP and others. Furthermore, it may be recycled and is completely biodegradable.