Increasingly stringent environmental and consumer safety concerns have led for- mulators to explore new materials as replacements for paint stripping solvents such as methylene chloride, toluene, methanol and n-methyl-2-pyrrolidone (NMP). With the need for safer alternatives also comes the inability to sacrifice performanc
DMSO offers a unique combination of low toxicity and high solvent strength, making it an ideal solvent for stripping paint from a variety of surfaces.
Formulating with DMSO is straightforward. DMSO is compatible with:
- A wide range of cosolvents, including ethyl lactate, DBE, and alcohols
- Common Thickening agents, including Klucel ® (Hercules), Methocel ® (Dow), and Carbopol ® (Noveon)
- Nonionic Surfactants, including Igepal ® and Ninol ® (Stepan Corp.)
- Performance additives for corrosion con trol (Cobratec ® , PMC specialities), and fragrances
A suggested formulation for general paint stripping is given below. For a stronger product, increase the DMSO level, at the expense of DBE and AR150. To produce the most biodegradable and water washable product, remove the AR-150 ND from the formula.
AR-150ND ® is a product of the ExxonMobil Corporation.
DBE ® (dibasic ester blends) are products of DuPont. Monsanto markets a similar product line (DME ® blends)
EEP (3-ethoxyethylpropionate) is produced by Eastman Chemical Company Methocel ® thickeners are produced by Dow Chemical.
RhodaSurf ® DA-630 is a product of Rhodia.
The intent of this bulletin is to provide the process chemist or engineer with a basic understanding of dimethyl sulfoxide (DMSO) recovery and information such that he or she can design and construct a system to fit specific conditions and requirements. Included is information regarding materials of construction and a typical recovery schematic diagram. Because individual system conditions vary widely, e.g., water concentration, impurity type and concentration, DMSO purity constraints, etc., this bulletin cannot cover specific system designs.
Dimethyl sulfoxide can be efficiently recovered from aqueous solutions, even though originally con- taminated with volatile and/or nonvolatile impurities. Commercial users of DMSO employ a variety of processing schemes in their DMSO recovery system. All of these are based on evaporation or frac- tional distillation because of simplicity of design and operation. Unlike many polar solvents, DMSO can be easily separated from water by distillation in substantially pure form.
Recovery operations are generally designed on a basis of economics balancing cost of solvent loss with capital and operating costs. However, air and water quality is becoming an important con- sideration in recovery design. Therefore, we have also attempted to answer environmental ques- tions on DMSO in this bulletin.
If the reader desires further information, particularly regarding uses, chemical properties or toxicity, other bulletins on DMSO are available at www.gaylordchemical.com.
The information in this booklet is based on information available to us and on our observations and experiences. However, no warranty is expressed or implied regarding the accuracy of this data, the results to be obtained from the use thereof, or that any use will not infringe any patent. Each user must establish appropriate procedures for off-loading, handling, and use of the product(s). Since conditions for use are beyond our control, we will make no guarantee of results, and assume no liability for damages incurred by off-loading, handling, or use of the product(s). Nothing herein constitutes
permission, or recommendation to practice any invention covered by any patent without license from the owner of the patent.