EMULSION TERPOLYMERIZATION OF DIMETHYL META-ISOPROPENYL BENZYL ISOCYANATE (TMI(R)) WITH ACRYLIC-MONOMERS - PROCESS-DEVELOPMENT AND KINETICS

Dimethyl meta-isopropenyl benzyl isocyanate (TMI(R)) is a bifunctional monomer possessing a double bond and an isocyanate group. Emulsion te rpolymerization of TMI with the acrylic monomers, methyl methacrylate and n-butyl acrylate, was studied. Polymerizations were carried out at 40 degrees C using a redox initiator system in order to minimize the extent of hydrolysis of the isocyanate in the aqueous emulsion environ ment. The kinetics of the polymerization reaction were investigated. T he polymerization rate was found to decrease with increasing TMI conce ntration. The effects of several preparative variables such as the mon omer, surfactant, and initiator concentration on the polymerization ki netics was studied. Several semicontinuous polymerization processes we re developed in order to enhance the incorporation of TMI at appreciab le rates. These processes also allow us to control the polymer composi tion, latex particle size, and the locus of isocyanate groups in the l atex particle. Process variables such as the mode of initiator additio n (batch versus semicontinuous) were found to greatly influence the po lymerization behavior. (C) 1996 John Wiley & Sons, Inc.