Polymer-supported titanium catalysts for syndiotactic polymerization of styrene

✍ Scribed by Guangqian Yu; Hui Chen; Xuequan Zhang; Zijiang Jiang; Baotong Huang

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 339 KB
• Volume: 34
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(199608)34:11<2237::aid-pola18>3.0.co;2-g

✦ Synopsis

Poly(styrene-co-acrylamide)(PSAm)-titanium complexes (PSAm * Ti) were prepared and characterized. It is found that the coordination number of acrylamide (Am) to T i 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 (MA0 = methylaluminoxane) is highly syndiotactic. Use of Et3Al and i-Bu3Al in place of M A 0 gives atactic polystyrene. The activities of the various aluminum compounds used as the cocatalysts decrease in the order: M A 0 > Et3A1 > 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.