Persulfate Applications
Persulfates are key components in many industrial processes and
commercial products.
The polymer industry uses aqueous solutions of persulfates as initiators in
the polymerization of latex and synthetic rubber. The electronics industry
considers sodium persulfate an efficient microetchant in the manufacture of
printed circuit boards. The following examples further illustrate the
chemical versatility of persulfates.
Polymerization
Plastics and rubber — Ammonium, potassium, and sodium persulfates
are used as initiators for emulsion polymerization reactions in the
preparation of acrylics, polyvinyl chlorides, polystyrenes, and neoprene.
They are used as polymerization initiators in the manufacture of synthetic
rubber (styrene butadiene and isoprene) for automobile and truck tires.
Persulfate initiation is used to prepare latex polymers for paints, coatings,
and carpet backing.
Structural materials — Persulfates are used as initiators in polymeric
concrete formulations.
Inorganic chemicals and minerals — Persulfates are also
initiators for the polymeric coating of graphite filaments.
Soil stabilization — Ammonium persulfate is used as a curing agent in
chemical grout systems used to stabilize soil near dams, tunnels,
and buildings.
Oxidation
Surface preparation — The oxidation power of persulfates
is used to clean and microetch a variety of printed circuit
board substrates.
Persulfates are important oxidants in plating and coating
processes. They are also etchants for nickel, titanium, and
zink alloys.
Persulfates are used to clean and mill aluminum, brass, copper, and many
other metal surfaces prior to plating or adhesive bonding.
Persulfates are used to clean and activate carbon and
charcoal before and after their use as absorbents.
Cosmetics — The cosmetic industry has developed formulations which
use persulfates to boost hair bleaching performance.
Organic synthesis — Persulfates are oxidizing agents in
the preparation of aldehydes, ketones, carboxylic acids,
quinones, and a variety of other compounds.
The pharmaceutical industry uses sodium persulfate
as a reagent in the preparation of antibiotics.
Other Applications
Adhesive — Persulfates are used in the preparation of adhesive films and
metal bonding adhesives.
Gas and oil production — In enhanced oil recovery, persulfates are used
"down hole" for gel forming and breaking.
Inks, pigments, and dispersants — Persulfates are used to graft
substrates to polymers (for example, carbon black to sodium acrylate).
Persulfates are used in the preparation of dispersants for ink jetting and
toner formulations.
Mining — Persulfates can be used in nickel and cobalt separation processes.
Peroxymonosulfate — FMC developed a process using ammonium and
sodium persulfates to prepare peroxymonosulfate solutions.
This patented process allows fast, efficient,
on-site production of an alternative to Caro's acid and potassium caroate.
Photography — Persulfates are used in many
photographic applications, including bleaching solutions, solution
regeneration, equipment cleaning, and waste water treatment.
Pulp and paper — Persulfates are used in the sizing of
paper, preparation of binders and coatings, and production
of special papers.
An activated alkali metal persulfate effectively repulps neutral/alkaline
wet-strength broke and decolorizes dyes and optical brightener.
Textiles — Ammonium and sodium persulfates are used in
the desizing and bleaching of textiles and the development
of dyestuffs.
Swimming pools — Clear Advantage® shock treatment is
used to oxidize non-filterable waste in swimming pools and
other recreational water. Clear Advantage® shock clarifies
water and prevents the formation of combined chlorine.
Environmental — Persulfates are very strong oxidants,
have excellent shelf life when stored properly, and are economical to use.
These properties make persulfates suitable for a variety of environmental
applications, such as soil remediation and wastewater/groundwater cleanup.