Determination of the mode of radical termination from pulsed laser polymerization experiments in the presence of retardation and chain transfer to agent

摘要

The pulsed laser polymerization-high termination rate limit-size-exclusion chromatography (PLP-HTRL-SEC) technique is used to estimate the mode of termination (δ) for n-butyl methacrylate (n-BMA) polymerization at 30 °C. It is found that molecular mass distributions measured in these experiments are influenced by an unknown side reaction such as retardation or chain transfer that results in a marked decrease of intensity of the PLP peak. A new approach is developed to evaluate δ, with numerical experiments used to demonstrate the robustness of the methodology in the presence of retardation or chain transfer to agent. Application to the experimental n-BMA polymerization at 30 °C leads to an estimate for δ of 0.60 ± 0.03. The pulsed laser polymerization-high termination rate limit-size-exclusion chromatography (PLP-HTRL-SEC) method is extended to estimate the mode of termination (δ) even in the presence of side reactions such as retardation or chain transfer to agent. By applying this method for n-BMA polymerization at 30 °C, δ is estimated to be 0.60 ± 0.03.