Free‐radical polymerization with long‐chain branching: Batch polymerizations of vinyl acetate in t‐butanol

Vinyl acetate was batch polymerized at 60°C in t‐butanol solution. Conversion and molecular weights were measured as functions of time for several initiator and solvent concentrations. Although the overall rate constant depends somewhat on solvent concentration, the reaction is first order in monomer concentration up to at least 60% conversion and one‐half order in the concentration of initiator. Molecular weights were independent of initiator concentration, confirming that the polymerization is transfer dominated. Measurements of M̄w and M̄w versus conversion were used to establish the individual transfer constants. All are independent of solvent concentration, except Cp, the polymer transfer constant, which decreases systematically with increasing solvent concentration.