THE COURSE OF EMULSION POLYMERIZATION OF VINYL-ACETATE USING REDOX SYSTEMS OF DIFFERENT OXIDIZING-AGENTS

The emulsion polymerization of vinyl acetate (VAc) was carried out by using redox initiation systems of different persulfate cations such as potassium persulfate (PPS), sodium persulfate (SPS), and ammonium per sulfate (APS); each of them was coupled with developed acetone sodium bisulfite adduct (AcSBS) as a reducing agent. The rate of polymerizati on was found to be dependent on the initiator concentration to the pow ers 1.04, 1.02, and 0.34, respectively. The effect of the different ca tions of the oxidizing agents upon the stability of the prepared emuls ion lattices was studied by using the sedimentation method. The effect of the different cations on the morphological characteristics of some of the produced lattices was also studied. Finally, the activation en ergies of these reactions for potassium, sodium, and ammonium persulfa te were found to be 0.84 x 10(4), 1.92 x 10(4), and 6.68 x 10(4) J/mol , respectively. (C) 1997 John Wiley & Sons, Inc.