Design of Hard Water Stable Emulsifier Systems for Petroleum- and Bio-based Semi-synthetic Metalworking Fluids

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• 作者：Julie B. Zimmerman ; Andres F. Clarens ; Kim F. Hayes ; and Steven J. Skerlos
• 刊名：Environmental Science & Technology
• 出版年：2003
• 出版时间：December 1, 2003
• 年：2003
• 卷：37
• 期：23
• 页码：5278 - 5288
• 全文大小：395K
• 年卷期：v.37,no.23(December 1, 2003)
• ISSN：1520-5851

文摘

Metalworking fluids (MWFs) increase productivity andthe quality of manufacturing operations by cooling andlubricating during metal forming and cutting processes.Despite their widespread use, they pose significanthealth and environmental hazards throughout their lifecycle. An obvious environmental improvement to MWFtechnology would be to improve the lifetime of the fluidwhile utilizing more environmentally friendly and lessenergy-consuming materials without compromisingexisting performance levels. This investigation focuseson the design of mixed anionionc:nonionic emulsifiersystems for petroleum and bio-based MWFs that improvefluid lifetime by providing emulsion stability under hardwater conditions, a common cause of emulsion destabilizationleading to MWF disposal. Experimental conditions weredesigned to evaluate the impact of emulsifier structuralcharacteristics (straight chain, branched tail, branchedhead) and the molar ratios of anionic to nonionic surfactantand oil to total surfactant. Results from the 2500 formulationsgenerated indicate that the use of a twin-headed anionicsurfactant can provide improved hard water stability forboth mineral oil- and vegetable oil-based formulations, evenin the absence of a chelating agent and a coupler.Results also suggest that an oil:total surfactant molarratio of 0.5 or less is necessary for particle size stabilityin hard water conditions for these systems. The newlydeveloped petroleum and bio-based formulations withimproved hard water stability are competitive withcommercially available MWFs in performance evaluationsfor tramp oil rejection, contact angle, and tapping torqueefficiency. These results can be used to design MWFformulations with fewer components and extended lifetimeunder hard water conditions, both of which would leadto a reduction in the life cycle environmental impact ofMWFs.