Influence of DMF on the polymerization of tert-butyl acrylate initiated by 4-oxo-TEMPO-capped polystyrene macroinitiator
Journal
Polymer International
Journal Volume
57
Journal Issue
5
Pages
730-737
Date Issued
2008
Author(s)
Abstract
Backgroud: 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 κact-tBA of alkoxyamine increased and the recombination rate constant κrec-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 κact-tBA and a decrease in κ rec-tBA. © 2008 Society of Chemical Industry.
Type
journal article