It is well known that utilizing a redox pair is an effective way to reduce free monomer at the end of an emulsion polymerization process. This is because a redox couple generates a large amount of free radicals capable of converting low levels of free monomer. The ability to use redox chemistry for initiation of main polymerization is also known to be effective. For some systems, these redox reactions can be done at or below room temperature.
A new family of advanced sulfinic acid derivative reducing agents has been developed that offer higher reactivity when compared to conventional reducing agents in the post polymer-ization. This work was undertaken to determine if they could be used for the initiation of main polymer-ization, and what impact they would have on polymer properties, performance and monomer conversion.