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Influence of DMF on the polymerization of tert ‐butyl acrylate initiated by 4‐oxo‐TEMPO‐capped polystyrene macroinitiator
Author(s) -
Kuo KuoHuai,
Chiu WenYen,
Cheng KuoChung
Publication year - 2008
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.2400
Subject(s) - polymer chemistry , copolymer , polymerization , polystyrene , dispersity , acrylate , materials science , styrene , living polymerization , chemistry , radical polymerization , polymer , composite material
BACKGROUND: In a number of studies it has been shown that 2,2,6,6‐tetramethylpiperidinooxy (TEMPO)‐mediated polymerization of acrylates is not facile. Therefore, the object of the study reported here was to prepare poly[styrene‐ block ‐( tert ‐butyl acrylate)] (PS‐b‐PtBA) block copolymers using 4‐oxo‐TEMPO‐capped polystyrene macroinitiator as an initiator, in the presence of small amounts of N , N ‐dimethylformamide (DMF). The kinetic analysis and the effect of DMF on the reaction mechanism are also discussed. RESULTS: PS‐b‐PtBA block copolymer was prepared through polymerization of tert ‐butyl acrylate (tBA) initiated by 4‐oxo‐TEMPO‐capped polystyrene macroinitiator at 135 °C. The polymerization rate of tBA could be increased by adding a small amount of DMF, and the number average molecular weight of the PtBA block in PS‐b‐PtBA reached 10 000 g mol −1 with narrow polydispersity. The activation rate constant k act−tBA of alkoxyamine increased and the recombination rate constant k rec−tBA decreased with increasing DMF concentration. CONCLUSION: DMF was shown to be a rate‐enhancing additive for the polymerization of tBA using a 4‐oxo‐TEMPO‐capped polystyrene macroinitiator. From the kinetic analysis, it was concluded that the improvement of polymerization with the addition of DMF was due to an increase in k act−tBA and a decrease in k rec−tBA . Copyright © 2008 Society of Chemical Industry