Sharif Digital Repository

This research relates to an improved method for making surfactant esters, especially sorbitan monostearate and tristearate. Sorbitan esters of fatty acid, stearate are derived from a reaction between sorbitan and fatty acid. Sorbitan fatty acid ester called sorbitan ester, are surfactants highly safe to use on human body and are widely used as a food additive in the production process as emulsifiers. Sorbitan esters are well known emulsifiers suitable for use in food, pharmaceutical products as well as many other applications. Despite its simple name, sorbitan ester is complex mixture of molecules. One such technique involves direct esterification of sorbitol or an intramolecular condensate... 

Synthetic based fluid has been introduced since 1990 as an alternative to conventional oil-based fluid, which, like oil-based mud, is effective wherever the use of water-based mud is problematic. This type of fluid with similar performance to oil-based mud is environmentally acceptable and the safety of working with this fluid is higher for drilling rig personnel. cutting drilled with synthetic base fluid can be discharged into ocean and sea waters, and this can reduce the total cost of drilling compared to oil-based mud because there isn't need to transport the cutting to offshore and dispose of them and consequently drilling is reduced. In terms of safety, these fluids reduce the risk of...