writer：Xiujuan Huang, Yan Xiao*, and Meidong Lang*
keywords：ATRP; six-arm copolymers; monomer reactivity ratios; self-assembly; salt effect.
source：期刊
Issue time：2012年

A series of star-shaped poly(ε-caprolactone) (PCL)-based diblock and triblock copolymerscontaining 2-(Dimethylamino)ethyl methacrylate (DMAEMA or DMA) and oligo(ethylene glycol)monomethyl ether methacrylate (OEGMA or OEG) were synthesized in one pot by atom transfer radical polymerization (ATRP) using a six-arm PCL-based macroinitiator. The precursor and the resultant copolymers were characterized via ¹H NMR and size exclusion chromatography (SEC). The monomer reactivity ratios for DMAEMA (r₁) and OEGMA (r₂) were estimated to be near unity and r₁×r₂ = 1, indicating the random distribution of the monomers in the final copolymers. Self-assembly behavior of these copolymers was investigatedby fluorimetry, ¹H NMR, DLS, TEM, potentiometric titrations and zeta potential measurements.The results suggested that the star copolymers were responsive to salinity depending on their composition and structure.