Styrene polymerization catalyzed by metal porphyrin complex/MAO for in situ synthesizing polystyrene containing air stable π cation radicals

• Published in: Journal of polymer science. Part A, Polymer chemistry Polymer chemistry, 2008-02, Vol.46 (4), p.1240-1248
• Main Authors: Li, Jianzhong, Li, Min, Li, Shiyun, Shi, Liya, Ren, Changyi, Cui, Dongmei, Wang, Yanhui, Tang, Tao
• Format: Article
• Language: English
• Subjects: Applied sciences; cation radicals; coordination mechanism; Exact sciences and technology; Organic polymers; organometallic catalysts; Physicochemistry of polymers; Polymerization; polystyrene; porphyrin; Preparation, kinetics, thermodynamics, mechanism and catalysts; synthesis
• ISSN: 0887-624X; 1099-0518
• DOI: 10.1002/pola.22465

A novel catalyst system based on nickel(II) tetraphenylporphyrin (Ni(II)TPP) and methylaluminoxane for styrene polymerization was developed. This catalyst system has a high thermal stability and show fairly good activity. The obtained polystyrene (PS) was isotactic-rich atactic polymer by ¹³C NMR analysis, and its molecular weight distribution was rather narrow (Mw/Mn [almost equal to] 1.6, by GPC analysis). ESR revealed that Ni(II)TPP π cation radicals were formed in the polymerization and could remain in the resulting PS stably. The mechanism of the polymerization was discussed and a special coordination mechanism was proposed. The PS product containing Ni(II)TPP π cation radicals can be used as a potential functional material. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1240-1248, 2008