Eur. Phys. J. E 5, 5-12
Triblock copolyampholytes from 5-(N,N-dimethyl amino)isoprene, styrene, and methacrylic acid: Synthesis and solution properties
R. Bieringer1, V. Abetz1 and A.H.E. Müller1, 21 Makromolekulare Chemie II, Universität Bayreuth, 95440 Bayreuth, Germany
2 Bayreuther Zentrum für Kolloide und Grenzflächen, 95440 Bayreuth, Germany
volker.abetz@uni-bayreuth.de
(Received 15 March 2000 )
Abstract
ABC triblock copolymers of the type
poly[5-(N,N-dimethyl amino)isoprene]-block-polystyrene-block-poly(tert-butyl methacrylate) (AiST) were synthesized and hydrolyzed to yield poly[5-(N,N-dimethyl amino)isoprene]-block-polystyrene-block-poly(methacrylic acid) (AiSA) triblock copolyampholytes. Due to a complex solubility
behavior the solution properties of these materials had to be investigated in THF/water solvent
mixtures. Potentiometric titrations of AiSA triblock copolyampholytes showed two inflection
points with the A block being deprotonated prior to the Ai hydrochloride block thus forming a
polyzwitterion at the isoelectric point (iep). The aggregation behavior was studied by dynamic
light scattering (DLS) and freeze-fracture/transmission electron microscopy (TEM). Large
vesicular structures with almost pH-independent radii were observed.
61.16.Bg - Transmission, reflection and scanning electron microscopy (including EBIC).
61.25.Hq - Macromolecular and polymer solutions; polymer melts; swelling.
81.05.Lg - Polymers and plastics; rubber; synthetic and natural fibers; organometallic and organic materials.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2001