Controlled Radical Polymerization at High Conversion: Bulk ICAR ATRP of Methyl Methacrylate
| Autor: | Shiping Zhu, Ali Mohammad Rabea |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
chemistry.chemical_classification
Atom-transfer radical-polymerization General Chemical Engineering Dispersity Radical polymerization General Chemistry Polymer Photochemistry Industrial and Manufacturing Engineering chemistry.chemical_compound Polymerization chemistry Polymer chemistry Molar mass distribution Methyl methacrylate |
| Zdroj: | Industrial & Engineering Chemistry Research. 53:3472-3477 |
| ISSN: | 1520-5045 0888-5885 |
| DOI: | 10.1021/ie403731m |
| Popis: | Methyl methacrylate (MMA) was polymerized in bulk via atom transfer radical polymerization (ATRP) with azobis(isobutyronitrile) (AIBN) and tert-butyl peroxybenzoate (TBPB) as initiator for continuous activator regeneration (ICAR). The ATRP was first carried out up to high conversion at 70 °C. When the system reached its glass state at about 94%, the polymerization temperature was elevated to 120 °C to maximize the conversion. Livingness of the ICAR ATRP process and control of polymer molecular weight at high conversion were carefully examined to elucidate the mechanisms of diffusion-controlled reactions. The “gel effect” started at about 50% conversion, and it was accompanied by molecular weight distribution broadening. A dramatic increase in polydispersity was observed at above 90% conversion. The loss of control over molecular weight was caused by diffusion-controlled deactivation, which could be reduced to some extent by increasing deactivator concentration. However, despite the loss of control at high... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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