Controlled radical polymerization of styrene and methyl acrylate in the presence of reversible addition-fragmentation chain transfer agents, phenylethyl phenyl dithioacetate and phenyldithioacetic acid
| Autor: | Michael R. Whittaker, Michael J. Monteiro, Yong Keng Goh |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
congenital
hereditary and neonatal diseases and abnormalities Polymers and Plastics Bulk polymerization health care facilities manpower and services education Organic Chemistry Radical polymerization Chain transfer Styrene chemistry.chemical_compound Monomer chemistry Polymerization health services administration Polymer chemistry Materials Chemistry Living polymerization Methyl acrylate |
| Zdroj: | Journal of Polymer Science Part A: Polymer Chemistry. 43:5232-5245 |
| ISSN: | 1099-0518 0887-624X |
| DOI: | 10.1002/pola.21020 |
| Popis: | The use of phenyldithioacetic acid (PDA) in homopolymerizations of styrene or methyl acrylate produced only a small fraction of chains with dithioester end groups. The polymerizations using 1-phenylentyl phenyldithioacetate (PEPDTA) and PDA in the same reaction showed that PDA had little or no influence on the rate or molecular weight distribution even when a 1:1 ratio is used. The mechanistic pathway for the polymerizations in the presence of PDA seemed to be different for each monomer. Styrene favors addition of styrene to PDA via a Markovnikov type addition to form a reactive RAFT agent. The polymer was shown by double detection SEC to contain dithioester end groups over the whole distribution. This polymer was then used in a chain extension experiment and the M-n was close to theory. A unique feature of this work was that PDA could be used to form a RAFT agent in situ by heating a mixture of styrene and PDA for 24 h at 70 degrees C and then polymerizing in the presence of AIBN to give a linear increase in Mn and low values of PDI (< 1.14). In the case of the polymerization of MA with PDA, the mechanism was proposed to be via degradative chain transfer. (c) 2005 Wiley Periodicals, Inc. |
| Databáze: | OpenAIRE |
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