Hydrophobically controlled self‐association of pH‐ and thermo‐sensitive triblock copolymers based on poly(acrylic acid‐co‐tert‐butyl acrylate) and poly(propylene oxide). Issue 19 (1st June 2016) - Pottier, Christophe
ABSTRACT: Aqueous solution properties of amphiphilic P(AA‐ co ‐ t BA)‐ b ‐PPO‐ b ‐ P(AA‐ co ‐ t BA) copolymers having various t BA contents are presented in this article. These copolymers show pH‐sensitive behavior depending on t BA/AA ratio. Hydrophobic interactions between t BA units leading to pH‐dependent macroscopic aggregates were evidenced by turbidimetry. The aggregation behavior of the PPO middle block was concealed in presence of t BA units. The formation of water‐soluble aggregated objects was characterized by Asymmetrical Flow Field Flow Fractionation (AsF4). By increasing t BA/AA ratio, we observed an increase of aggregates size as well as a reduction of the critical concentration aggregation. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys.2016, 54, 1944–1949 Abstract : The control of properties of pH‐ and thermo‐responsive polymers is of increasing interest particularly for biomedical applications. These properties can be highly influenced by introducing hydrophobic or hydrophilic moieties in the polymer. Amphiphilic triblock P(AA‐ co ‐ t BA)‐ b ‐PPO‐ b ‐P(AA‐ co ‐ t BA) copolymers having various t BA contents are presented in this article. These copolymers self‐assembled in macroscopic aggregates under a critical pH. At higher pH, soluble aggregates having a size which increases with higher t BA/AA ratio were characterized by Asymmetrical Flow Field Flow Fractionation.