Luu T T H, Jia Z, Kanaev A, Museur L
Laboratoire de Physique des Lasers CNRS UMR 7538, Université Sorbonne Paris Nord, F-93430 Villetaneuse, France.
Laboratoire des Sciences des Procédés et des Matériaux CNRS UPR 3407, Université Sorbonne Paris Nord, F-93430 Villetaneuse, France.
J Phys Chem B. 2020 Aug 6;124(31):6857-6866. doi: 10.1021/acs.jpcb.0c03140. Epub 2020 Jul 23.
The effect of UV light intensity on the kinetics of free-radical polymerization of 2-hydroxyethyl methacrylate (HEMA) triggered with the phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO) photoinitiator was investigated experimentally and theoretically. The temporal evolution of the conversion yield and polymerization rate was followed by Raman spectroscopy. The experimental data were treated with a kinetic model, which takes into account significant diffusion-controlled processes and termination pathways including bimolecular reaction and primary radical termination. This model showed very good agreement with the experiment in a large range of UV light intensities and shed light on the termination process. In particular, it was shown that the primary radical termination is dominant for relatively low light intensities below 1 mW/cm, when the photoinitiator is weakly consumed during the polymerization process.
实验和理论研究了紫外光强度对苯基双（2,4,6-三甲基苯甲酰基）氧化膦（BAPO）光引发剂引发的甲基丙烯酸2-羟乙酯（HEMA）自由基聚合动力学的影响。通过拉曼光谱跟踪转化率和聚合速率的时间演变。用动力学模型处理实验数据，该模型考虑了显著的扩散控制过程和终止途径，包括双分子反应和初级自由基终止。该模型在大范围的紫外光强度下与实验结果吻合良好，并揭示了终止过程。特别是，结果表明，当光引发剂在聚合过程中消耗较弱时，在低于1 mW/cm的相对低光强度下，初级自由基终止占主导地位。
