Control of methyl methacrylate radical polymerization via Enhanced Spin Capturing Polymerization (ESCP)

✍ Scribed by Lin Zang; Edgar H.H. Wong; Christopher Barner-Kowollik; Thomas Junkers

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 391 KB
• Volume: 51
• Category: Article
• ISSN: 0032-3861
• DOI: 10.1016/j.polymer.2010.06.040

✦ Synopsis

a b s t r a c t

The nitrone mediated polymerization of methyl methacrylate (MMA) via the enhanced (termination) spin capturing polymerization (ESCP) process is made possible via the addition of small amounts of styrene (between 5 and 10 vol.%) to the reaction mixture. Efficient control over the molecular weight between 7000 and 57,000 g mol À1 (at 60 C) yields macromolecules that feature a mid-chain alkoxyamine functionality and are rich in methyl methacrylate. The collated kinetic and molecular weight data allow for a deduction of the spin capturing constant, C SC , in the range between 0.15 and 0.30. During the ESCP process, the number average molecular weight, M n , of the formed mid-chain functional polymer is constant up to high monomer to polymer conversions (i.e. 80%). The high degree of alkoxyamine midchain functionality present in the generated polymeric material is evidenced via a subsequent nitroxidemediated polymerization process employing the formed ESCP polymer, indicating a chain extension from 37,700 to 118,000 g mol À1 with a concomitant reduction in polydispersity (from 2.3 to 1.5).