ESR Study of MMA Batch Emulsion Polymerization in Real Time: Effects of Particle Size
ESR Study of MMA Batch Emulsion Polymerization in Real Time: Effects of Particle Size
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MMA 间歇乳液聚合实时 ESR 研究：粒径的影响
DOI：
10.1021/ma951652o
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发表时间：
1996
期刊：
影响因子：
5.5
通讯作者：
H. Chang
中科院分区：
文献类型：
--
作者：
Hsing;D. G. Westmoreland;H. Chang
采用连续流动体系和电子自旋共振时间扫描实验相结合的方法，研究了甲基丙烯酸甲酯(MMA)间歇乳液聚合。该系统基本上可以连续监测反应过程中不断传播的自由基浓度。聚合反应由氧化还原引发剂体系在较低温度(45℃)下引发。用该技术研究了不同胶乳粒径对聚合动力学的影响。研究表明，胶乳颗粒大小对PMMA传播自由基浓度分布有显著影响，这可能是由于改变了自由基终止反应的平衡。这项研究还提供了乳胶粒子中传播的PMMA自由基分布不均匀的证据。提出的不均匀性的大小取决于颗粒的大小。
An experimental methodology has been developed which combines a continuous-flow system and an electron spin resonance time sweep experiment to study the batch emulsion polymerization of methyl methacrylate (MMA). This system allows essentially continuous monitoring of the propagating free-radical concentration during the reaction. The polymerization was initiated by a redox initiator system at a relatively low temperature (45 °C). This technique has been used to study the effect of varying latex particle size on polymerization kinetics. This study demonstrates that latex particle size has a significant effect on the PMMA propagating radical concentration profile, which is hypothesized to be due to changing the balance of the radical termination reactions. This study also provides evidence for an inhomogeneous distribution of the propagating PMMA radicals in the latex particle. The magnitude of the proposed inhomogeneity depends on the size of the particles.