Zhiping Peng, Dandan Wang, Xinxing Liu
Aug 15, 2007
Citations
0
Influential Citations
29
Citations
Journal
Journal of Polymer Science Part A
Abstract
Triblock copolymers of poly(styrenesulfonate)-b-poly(ethylene glycol)-b-poly(styrenesulfonate) with narrow molecular weight distribution (M w /M n = 1.28-1.40) and well-defined structure have been synthesized in aqueous solution at 70 °C via reversible addition-fragmentation chain transfer polymerization. Poly(ethylene glycol) (PEG) capped with 4-cyanopentanoic acid dithiobenzoate end groups was used as the macro chain transfer agent (PEG macro-CTA) for sole monomer sodium 4-styrenesulfonate. The reaction was controllable and displayed living polymerization characteristics and the triblock copolymer had designed molecular weight. The reaction rate depended strongly on the CTA and initiator concentration ratio [CTA] 0 /[ACPA] 0 : an increase in [CTA] 0 /[ACPA] 0 from 1.0 to 5.0 slowed down the polymerization rate and improved the molecular weight distribution with a prolonged induction time. The polymerization proceeded, following first-order kinetics when [CTA] 0 /[ACPA] 0 = 2.5 and 5.0.