A series of copolymers containing 50 mol % acrylic acid (AA) and 50 mol % butyl acrylate (BA) but with differing composition profiles ranging from an AA‐BA diblock copolymer to a linear gradient poly(AA‐grad‐BA) copolymer were synthesized and their pH‐responsive self‐assembly behavior was investigated. While assemblies of the AA‐BA diblock copolymer were kinetically frozen, the gradient‐like compositions underwent reversible changes in size and morphology in response to changes in pH. In particular, a diblock copolymer consisting of two random copolymer segments of equal length (16 mol % and 84 mol % AA content, respectively) formed spherical micelles at pH >5, a mix of spherical and wormlike micelles at pH 5 and vesicles at pH 4. These assemblies were characterized by dynamic light scattering, cryo‐transmission electron microscopy and small angle neutron scattering.
New phosphinoyl and thiophosphinoylcarbodithioates were synthesized in a one-pot reaction from the corresponding phosphinochalcogenides. Compounds of this new generation of thiocarbonylthio derivatives have been fully characterized by IR as well as (1)H, (31)P, and (13)C NMR spectroscopy and by mass spectrometry. Their solid-state structures reveal that they are isostructural but crystallize in different space groups. These new compounds are highly efficient reversible chain-transfer agents for the reversible addition-fragmentation chain transfer (RAFT) polymerization of styrene (St) and n-butyl acrylate (nBA), with controlled number-average molecular weights (Mn) and narrow dispersity values (Ð<1.3). The controlled character of the polymerization was further exemplified by MALDI-TOF mass spectrometry and the synthesis of PSt-P(nBA) diblock copolymers.
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