Synthesis of poly(4-vinylpyridine) by reverse atom transfer radical polymerization

Autor: Van Nga Nguyen, Yoram Cohen, Gregory T. Lewis
Rok vydání: 2007
Předmět:
Zdroj: Journal of Polymer Science Part A: Polymer Chemistry. 45:5748-5758
ISSN: 1099-0518
0887-624X
DOI: 10.1002/pola.22324
Popis: Controlled radical polymerization of 4-vinylpyridine (4VP) was achieved in a 50 vol % 1-methyl-2-pyrrolidone/water solvent mixture using a 2,2'-azobis(2,4-dimethylpentanitrile) initiator and a CuCl 2 /2,2'-bipyridine catalyst-ligand complex, for an initial monomer concentration of [M] 0 = 2.32-3.24 M and a temperature range of 70-80 °C. Radical polymerization control was achieved at catalyst to initiator molar ratios in the range of 1.3:1 to 1.6:1. First-order kinetics of the rate of polymerization (with respect to the monomer), linear increase of the number-average degree of polymerization with monomer conversion, and a polydispersity index in the range of 1.29-1.35 were indicative of controlled radical polymerization. The highest number-average degree of polymerization of 247 (number-average molecular weight = 26,000 g/mol) was achieved at a temperature of 70 °C, [M] 0 = 3.24 M and a catalyst to initiator molar ratio of 1.6:1. Over the temperature range studied (70-80 °C), the initiator efficiency increased from 50 to 64% whereas the apparent polymerization rate constant increased by about 60%.
Databáze: OpenAIRE
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