کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5185384 | 1381076 | 2009 | 6 صفحه PDF | دانلود رایگان |
A series of chromium/Schiff base complexes N,Nâ²-bis(salicylidene)-1,2-phenylenediamino chromiumIII X were prepared and employed for the alternating copolymerization of carbon dioxide with racemic propylene oxide in the presence of (4-dimethylamino)pyridine. The effect of the complex structure and reaction conditions on the catalytic activity, the poly(propylene carbonate)/cyclic carbonate (PPC/PC) selectivity, and the polymer head-to-tail linkages was examined. The experiments indicated that N,Nâ²-bis(3,5-di-tert-butylsalicylidene)-1,2-phenylenediamino chromiumIII (NO3) exhibited the highest PPC/PC selectivity as well as polymer head-to-tail linkages and N,Nâ²-bis(3,5-dichlorosalicylidene)-1,2-phenylenediimino chromiumIII (NO3) possessed the highest catalytic activity among these chromium/Schiff base complexes. The structure of the produced copolymer was characterized by the IR, 1H NMR, and 13C NMR measurements. Almost 100% carbonate content of the resulting polycarbonate were obtained with the help of these effective catalyst systems under facile conditions.
Journal: Polymer - Volume 50, Issue 2, 16 January 2009, Pages 441-446