MICROSUSPENSION POLYMERIZATION OF VINYL CHLORIDE.

The microsuspension polymerization of vinyl chloride was studied with respect to the type of stabilizing agent, method of pre-emulsification of the monomer, and effects of complexation between different water soluble and insoluble stabilizers. It was found that the simplest formulations based on single emulsifiers or protective colloid always resulted in small particle 'emulsion' polymer, very large particle 'suspension' polymer, or various forms of coagulum. The explanation offered for these phenomena was based on the analogy with other emulsion systems where phase inversion takes place. The most promising microsuspension formulations were those involving an anionic petroleum sulfonate, a nonionic surfactant of very low HLP, hydrocarbons from the petroleum sulfonate mixture, and a coupling agent such as a diol.