Anionic polymerization of Lewis acid-activated methyl methacrylate by enamines

✍ Scribed by Masatoshi Miyamoto; Shin-Ya Kanetaka

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 179 KB
• Volume: 37
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19991001)37:19<3671::aid-pola2>3.0.co;2-3

✦ Synopsis

A novel ionic polymerization of methyl methacrylate (MMA) with a series of enamines (1) in the presence of methylaluminum bis(2,6-di-tert-butylphenoxide) (2) was examined. Both nucleophile (1) and electrophile (2) are indispensable for the present polymerization, in which (1) acts as initiator and (2) as activator. MMA polymerization proceeded smoothly in toluene at or below room temperature (r.t.) in the presence of 1 and 2 (1 ϳ 4 mol %, respectively), went to completion within 1 h, and afforded syndiotactic-rich PMMA with molecular weight distribution (M w /M n ) in the 1.1 ϳ 1.4 range. The number-average molecular weight (M n ) of the polymer was significantly higher than that calculated from the feed ratio of 1 to the monomer, indicating low initiating efficiency. Kinetic studies coupled with isolation of an intermediate species proved that the real monomeric species involved in both initiation and propagation was a complex of MMA with 2. The effects of the concentrations of 1, 2, and MMA as well as the temperature of polymerization were also examined.