Editing Emulsion polymerization (section)

==History==
The early history of emulsion polymerization is connected with the field of synthetic rubber.<ref>{{cite journal|last1=Whitby|first1=G. S.|last2=Katz|first2=M.|title=Synthetic Rubber|journal=Industrial & Engineering Chemistry|volume=25|issue=12|year=1933|pages=1338–1348|doi=10.1021/ie50288a012}}</ref><ref>{{cite journal|last1=Hohenstein|first1=W. P.|last2=Mark|first2=H.|title=Polymerization of olefins and diolefins in suspension and emulsion. Part I.|journal=Journal of Polymer Science|volume=1|issue=2|year=1946|pages=127–145|doi=10.1002/pol.1946.120010207|bibcode=1946JPoSc...1..127H}}</ref> The idea of using an emulsified monomer in an aqueous suspension or emulsion was first conceived at [[Bayer]], before [[World War I]], in an attempt to prepare synthetic rubber.<ref>German patent 250690 (September 12, 1909)</ref><ref>Gottlob, Kurt. "Caoutchouc substance and process of making same" {{US Patent|1149577}}, filed January 6, 1913.</ref> The impetus for this development was the observation that natural rubber is produced at room temperature in dispersed particles stabilized by colloidal polymers, so the industrial chemists tried to duplicate these conditions. The Bayer workers used naturally occurring polymers such as [[gelatin]], [[ovalbumin]], and [[starch]] to stabilize their dispersion. By today's definition these were not true emulsion polymerizations, but [[suspension polymerization]]s.

The first "true" emulsion polymerizations, which used a [[surfactant]] and polymerization initiator, were conducted in the 1920s to polymerize [[isoprene]].<ref>German patent 558890 (filed January 8, 1927)</ref><ref>Dinsmore, Ray P. "Synthetic rubber and method of making it" {{US Patent|1732795}}, filed September 13, 1927.</ref> Over the next twenty years, through the end of [[World War II]], efficient methods for production of several forms of synthetic rubber by emulsion polymerization were developed, but relatively few publications in the scientific literature appeared: most disclosures were confined to patents or were kept secret due to wartime needs.

After World War II, emulsion polymerization was extended to production of plastics. Manufacture of dispersions to be used in [[paint|latex paints]] and other products sold as liquid dispersions commenced. Ever more sophisticated processes were devised to prepare products that replaced [[solvent]]-based materials. Ironically, synthetic rubber manufacture turned more and more away from emulsion polymerization as new [[organometallic]] catalysts were developed that allowed much better control of polymer architecture.