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Industrial Solvents
Solvents are used by all types of industries for processing, manufacturing, and formulating products. In industrial chemical processes, solvents are used in several process operational stages such as separation (gases, liquids and/or solids), reactions (reaction medium, reagent, carrier), washing, and many other operations. As part of formulated products, they are used in coatings, fabric, rubber products, adhesives, and thousands of other industrial and domestic products. In the cleaning product industry, they are used as cleaning agents or used in cleaning products. This is not the complete list, and solvents are used for other industrial, domestic, and research purposes. Allied with a wide range of benefits that solvents offer, environmental, health, and safety aspects, including human and eco-toxicity aspects, process safety and residual management should be considered. Therefore, guidelines orienting solvent development try to reduce the impact on the environment, putting a special emphasis on selection of the most appropriate solvent and the development of new solvents.
2.1. Definition Solvents are composed of chemicals found normally in a liquid state at room temperature and 1 atmospheric pressure and are capable of dissolving, suspending or extracting other substances without chemically altering them. A solution is made up of at least two components, a substance called solute and is dissolved in a solvent. Solutions are obtained by mixing solid, liquid and/or gaseous components with a liquid. When two liquid components are mixed together arbitrarily, the component with the molar excess is considered the solvent. When we talk about solution properties, our main interest is in the solute properties. Thus, choosing a solvent is based particularly on solute properties that we want to develop. The following characteristics are linked to solvents[1]: • • • • • • • •
Solventes 02.indd 20
Clean, colorless appearance; Volatilize without leaving a residual; Chemically inert; Light or pleasant odor; Low water content (anhydrous); Constant physical properties; Low toxicity; Biodegradability.
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