Sorbeth-30 Tetraoleate CAS No.: 63089-86-1

Typically, sorbitol is esterified with fatty acids or their anhydrides at temperatures between 130-180 °C, usually under acid catalysis. Sorbitol loses water at the temperature needed for esterification, resulting in three different isomers of sorbitan and (after losing another water molecule) isosorbide. These dehydration products form corresponding sorbitan esters when they interact with a fatty acid. These substances, also referred to as "spans," undergo ethoxylation to create polysorbates. In a different typical manufacturing process, ethylene oxide and a basic catalyst react with sorbitol at a temperature between 200 and 250°C. Sorbitol is isomerized in this situation as described above. Ethoxylated products, also known as carbowaxes, are produced when ethylene oxide is added. These products are then esterified with fatty acids to create oligomers of polyoxyethylene sorbitan esters (aka polysorbates).