Polymerization of styrene using novel bispyrazolylimine dinickel (II)/methylaluminoxane catalytic systems
Article first published online: 27 APR 2011
Copyright © 2011 Wiley Periodicals, Inc.
Journal of Applied Polymer Science
Volume 122, Issue 1, pages 545–550, 5 October 2011
How to Cite
Wang, Y.-y., Li, B.-x., Zhu, F.-m., Gao, H.-y. and Wu, Q. (2011), Polymerization of styrene using novel bispyrazolylimine dinickel (II)/methylaluminoxane catalytic systems. J. Appl. Polym. Sci., 122: 545–550. doi: 10.1002/app.34122
- Issue published online: 5 JUL 2011
- Article first published online: 27 APR 2011
- Manuscript Accepted: 3 JAN 2011
- Manuscript Received: 5 SEP 2010
- Doctor's Set-up Fund of Anhui University of Science and Technology. Grant Number: 2008YB032
- bispyrazolylimine dinickel (II);
- styrene polymerization;
- coordination mechanism
The polymerization of styrene with a series of bispyrazolylimine dinickel (II) complexes of bis-2-(C3HN2(R1)2-3,5)(C(R2) = N(C6H3(CH3)2-2,6)Ni2Br4 (complex 1: R1 = CH3, R2 = Ph; complex 2: R1 = CH3, R2 = 2,4,6-trimethylphenyl; complex 3: R1 = R2 = Ph; complex 4: R1 = Ph, R2 = 2,4,6-trimethylphenyl) in the presence of methylaluminoxane (MAO) was studied. The influences of polymerization parameters such as polymerization temperature, Al/Ni molar ratio, reaction time, and catalyst concentration on catalytic activity and molecular weight of the polystyrene were investigated in detail. The influence of the bulkiness of the substituents on polymerization activity was also studied. All of the four catalytic systems exhibited high activity (up to 10.50 × 105 gPS/(mol Ni h)) for styrene polymerization and provide polystyrene with moderate to low molecular weights (Mw = 4.76 × 104–0.71 × 104 g/mol) and narrower molecular weight distributions about 2. The obtained polystyrene was characterized by means of FTIR, 1H-NMR, and 13C-NMR techniques. The results indicated that the polystyrene was atactic polymer. The analysis of the end groups of polystyrene indicated that styrene polymerization with bispyrazolylimine dinickel complexes/MAO catalytic systems proceeded through a coordination mechanism. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.