Mean radical lifetimes and fluctuations in lifetime are shown to decrease with conversion and polydispersity index for atom transfer radical polymerization (ATRP) of both methyl methacrylate and styrene. In the first study of its kind, a comprehensive investigation of radical lifetimes in both ATRP and conventional free-radical polymerizations is reported using a kinetic Monte Carlo model. Quantile–quantile plots show the radical lifetimes to be exponentially distributed with equal mean and standard deviation. Radical lifetimes are shown to be thousands of times longer in conventional free-radical polymerization compared with ATRP. Reduced mean radical lifetimes and fluctuations offer a new perspective on the ATRP mechanism. Reduction in radical lifetime fluctuations ensures less variability in the number of monomer units added during the propagation steps and keeps the polydispersity index low. Deterministic models are used along with the kinetic Monte Carlo model to investigate several facets of these polymerization systems and are validated against experimental data.

中文翻译：

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原子转移自由基聚合中的自由基寿命：蒙特卡洛和确定性研究

对于甲基丙烯酸甲酯和苯乙烯的原子转移自由基聚合（ATRP），平均自由基寿命和寿命波动均随转化率和多分散指数的降低而降低。在此类研究中，首次报道了使用动力学蒙特卡洛模型对ATRP和常规自由基聚合反应中的自由基寿命进行的全面研究。分位数-分位数图显示了基本寿命以均值和标准差相等的指数分布。与ATRP相比，传统自由基聚合的自由基寿命被证明要长数千倍。平均自由基寿命的减少和波动为ATRP机制提供了新的视角。自由基寿命波动的减少确保了在扩散步骤中添加的单体单元数量的可变性较小，并使多分散指数保持较低。确定性模型与动力学蒙特卡洛模型一起使用，以研究这些聚合体系的几个方面，并针对实验数据进行了验证。