Potassium persulfate modes of thermal decomposition and reactions with ethyl acrylate in aqueous solution at 50°C in nitrogen atmosphere have been investigated. It has been found that the rate of persultate decomposition may be expressed as -d(&Oi-)/dt a (&Oi-)1.00*o.06 x (M)OS *OM while the steady state rate of polymerization ( RP) is given by R, a (&Oi-)050 * 0.05
x (M)lM*oM( in the concentration ranges of the persulfate, 10-3-10-2 (m/L), and monomer (M), 4.62-23.10 X lo-* (m/L), i.e, within its solubility range. In the absence of monomer, the rate of +fate decomposition was slow and first order in persulfate at the early stages of the reaction when the pH of the solution was above 3.0. The separatingpolymer phase was a stable colloid at low electrolyte concentrations even in the absence of micelle generators. It has been shown that the oxidation of water soluble monomeric and oligomeric radicals by the q O iions in the aqueous phase, viz, M; + GO;-+ M,-0-SO;
- SO;-, is not kinetically &&cant in this system. I t has been found that the reaction M + &Oi-+ 'M-0-SO; + SO;would also lead to chain initiation at the outset of the polymerization reaction. k has been estimated as 5.41 X (L/m/s) at 50°C. Taking kp as lo3 (L/m/s), k, has been estimated as 0.168 X lo6 (L/m/s). The partition coefficient (j3) of the monomer between the polymer phase and the aqueous phase was found to be 16 f 2, at 50°C. The rate constant for persulfate ion dissociation has been found as 1.40 x h s-' a t 50°C.