(1) A material added in small quantities to a solution to modify its characteristics. For example, additives may be added to a plating solution to modify the character of the deposit.
(2) In lubrication, a material added to a lubricant for the purpose of imparting new properties or of enhancing existing properties. Main classes of additives include anticorrosive, antifoam, antioxidant , antiwear, detergent , dispersant , extreme-pressure lubricant , and VI improver additives.
(3) In polymer engineering, a substance added to another substance, usually to improve properties, such as plasticizers , initiators, light stabilizers, and flame retardants.
