ISSN:
0887-624X
Keywords:
polymer support
;
titanium catalysts
;
syndiotactic polymerization
;
styrene polymerization
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Poly(styrene-co-acrylamide)(PSAm)-titanium complexes (PSAm · Ti) were prepared and characterized. It is found that the coordination number of acrylamide (Am) to Ti in the complexes is strongly dependent on Am content in PSAm, but not on [Am]/[Ti] ratio in the feed. The infrared and x-ray photoelectron spectra suggest that the polymer-supported complexes possess the structure The catalytic behavior of the complexes in styrene polymerization is described. The catalytic activity is markedly affected by [Al]/[Ti] ratio in the complexes. 13C NMR, IR, and DSC data indicate that the polystyrene obtained with PSAm · Ti/MAO (MAO = methylaluminoxane) is highly syndiotactic. Use of Et3Al and i-Bu3Al in place of MAO gives atactic polystyrene. The activities of the various aluminum compounds used as the cocatalysts decrease in the order: MAO 〉 Et3Al 〉 i-Bu3Al. The polymer-supported complexes show relatively high activity even after the complexes had been exposed to air for 19 h or higher polymerization temperature. © 1996 John Wiley & Sons, Inc.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
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