An engineer is studying the azodiisobutyronile-initiated polymerization of butyl acrylate in solution. She wants to change the monomer and initiator concentrations so as to double the initial steady-state rate of polymeriza tion without changing the number average degree of polymerization of the polymer or the reaction temperature. How should she proceed?
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An engineer is studying the azodiisobutyronile-initiated polymerization of butyl acrylate in solution. She wants to change the monomer and initiator concentrations so as to double the initial steady-state rate of polymeriza tion without changing the number average degree of polymerization of the polymer or the reaction temperature. How should she proceed?
The free radical polymerization of butyl acrylate has been studied in benzene solutions ranging from 1 to 5 mol·L–1 at 50°C using 2,2′‐azobisisobutyronitrile as initiator. Under the conditions of our experiments, both the effective rate coefficient for initiation, 2 f kd , and the coupled parameter, kp/kt1/2, (where kp and kt are the constants for propagation and termination reactions, respectively) are dependent on the monomer concentration. The 2 f kd value shows little increase with monomer concentration. The variation of the kp/kt1/2 parameter has been correlated with the chain length dependence of the termination rate coefficient. This effect is also responsible for the high dependence of the overall polymerization rate, Rp, onthe monomer concentration (1.49).