TY - JOUR
TI - Micellization of Miktoarm Star SnIn Copolymers in Block Copolymer/Homopolymer Blends
AU - E. Pavlopoulou
AU - S. H. Anastasiadis
AU - H. Iatrou
AU - M. Moshakou
AU - N. Hadjichristidis
AU - G. Portale
AU - W. Bras
JO - Macromolecules
PY - 2009
VL - 42
TODO - 14
SP - 5285--5295
PB - American Chemical Society (ACS)
SN - 0024-9297, 1520-5835
TODO - 10.1021/ma900696a
TODO - Aggregation numbers;  Copolymer chains;  Homopolymer;  Junction point;  Macromolecular architecture;  matrix;  Micellar core;  Micellization process;  Power-law dependences;  Quantitative agreement;  Simple model;  Small angle X-ray scattering;  Star copolymers;  Star-block copolymers;  Thermodynamic model, Block copolymers;  Copolymerization;  Macromolecules;  Micelles;  Micellization;  Polystyrenes;  X ray scattering, Plastic products
TODO - Aseries of miktoarm (polystyrene)n(polyisoprene)n, SnIn, star-block copolymers, comprising n equal arms of polystyrene and n equal arms of polyisoprene, is utilized to investigate the effect of macromolecular architecture on the characteristics of the micelles formed by the copolymers in a polyisoprene homopolymer matrix at various concentrations 0.05-2 wt%. The characteristics of the micelles are studied with small-angle X-ray scattering (SAXS) as a function of the functionality of the star copolymer n. The radius of the micellar core is found to be independent of n, the aggregation number decreases with increasing n exhibiting a n -1 power law dependence, while the volume fraction of copolymer chains participating in micelles is constant; these imply that the junction point of the copolymer does not affect the micellization process in any significant way. A simple thermodynamic model is developed following the methodology of Leibler in order to describe theoretically the micellization of AnBn copolymers in a B homopolymer matrix. The predictions of the model are in quantitative agreement with the experimental results, thus signifying that the assumptions of the simple model are valid. © 2009 American Chemical Society.
ER -