摘要
研究了聚乙二醇双苄醚络合碘化钠的行为,比较了PEG在苯乙烯-二乙烯苯共聚珠体上固载前后的相转移健化性能(正溴辛烷与固体NaI的反应)以及反应条件对催化反应的影响。结果表明,PEG浓度对其本征反应性有很大影响,PEG固载后其催化活性升高并在环取代率为15％时有一极大值。另外,催化反应速率随温度升高或溶剂极性增大而增大。从反应动力学、本征反应性和内扩散等方面讨论了实验结果。
The complex behavior of PEG-400(CH2Ph)2 (dibcnzyl ether of polyethylene glycol-400) with NaI and the phase-transfer catalytic activities of crosslinked polystyrene-supported PEG-400(CH2Ph ) ( monobenzyl ether ) and PEG-400-(CH2Ph)2 have been studied in the reaction of n-bromooctane with solid NaI. The complex way and intrinsic activity of PEG were greatly influenced by its concentration. In the solvent of xylene and n-octane , the catalytic activity of PEG immobilized on the polymer was increased and had a maximum value at the ring-substitution of 15%. Observed rate constant Jc (obsd) increased as the reaction temperature and the polarity of solvent increased, chlorobenzcne>xylene >n-octane. The results are discussed in terms of reaction kinetics, intrinsic reactivity and intraparticle diffusion.
