(1)Amaterialaddedinsmallquantitiestoasolutiontomodifyitscharacteristics.Forexample,additivesmaybeaddedtoaplatingsolutiontomodifythecharacterofthedeposit.
(2)Inlubrication,amaterialaddedtoalubricantforthepurposeofimpartingnewpropertiesorofenhancingexistingproperties.Mainclassesofadditivesincludeanticorrosive,antifoam,antioxidant,antiwear,detergent,dispersant,extreme-pressurelubricant,andVIimproveradditives.
(3)Inpolymerengineering,asubstanceaddedtoanothersubstance,usuallytoimproveproperties,suchasplasticizers,initiators,lightstabilizers,andflameretardants.