A variety of metal salts are used in polymer chemistry in various process steps within the production or targeted functionalization of polymers. Iron, copper and manganese salts are used during production itself for redox-initiated free radical polymerization.
Other polymerization reactions, such as that of styrene2, require various metal salts as buffers, stabilizers or acid scavengers. The use of calcium and magnesium citrates2 is particularly common here. For the emulsion polymerization of latex, salts such as calcium or magnesium nitrates or calcium acetate are used in coagulation solution processes. They play an important role as coagulants or de-emulsifiers.
Metal salts of aluminum can also be applied to stabilize the three-dimensional macrostructures of suitable polymers.
Polymeric foams such as polyethylene require a blowing agent that releases the gases which ultimately cause the polymer to foam. Suitable product for an endothermic supply of harmless carbon dioxide are citrates.
Also metal salts are employed in further processing of plastics. As efficient insulators, plastics often become electrostatically charged. During deliberate charging with corona wire, as in the production of polyester film, the use of magnesium salts as an additive can prevent unwanted electrostatic charging, or the electrostatic characteristics of the surface can be adapted as required.