- 作者: Hui-Ping Hsu and Jeng-Shong Shih
- 中文摘要:
Department of Chemistry, National Taiwan Normal University, Taipei, Taiwan 116, R.O.C.
Macrocyclic polyethers, e.g., crown ethers and cryptands, were prepared and employed as phase transfer catalysts for free radical polymerization of acrolein, a vinyl monomer, with persulfates (S2O82-) as initiators. The catalytic abilities of various macrocyclic polyethers as catalysts for the free radical polymerization of acrolein were found to be in the order: benzo-15-crown-5 > dibenzo-18-crown-6 > 12-crown-4 > 15-crown-5 > 18-crown-6 > cryptand-22 with sodium persulfate (Na2S2O8) as initiator. Sodium persulfate proved to be a better initiator than ammonium persulfate or potassium persulfate with benzo-15-crown-5 as a catalyst. Effects of solvents and temperature on the catalytic polymerization were also investigated. The polymerization rates in various solvents were in the order: dioxane > benzene > acetonitrile > acetone > dichloro methane > hexane > water. Comparison between bulk polymerization and solution polymerization was also made. Higher polymerization rate was observed at higher temperature. The molecular weights of polyacrolein and the conversion of monomer in reaction period were determined with gel permeation chromatography and ultra-violet spectrophotometry, respectively. Concentration effects of crown ether and initiator were also investigated and discussed. - 英文摘要: --
- 中文關鍵字: --
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