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Crystallization behavior of polyethylene/polystyrene A m B n miktoarm star copolymers
Author(s) -
Müller Alejandro J.,
Lorenzo Arnaldo T.,
Hirao Akira
Publication year - 2014
Publication title -
polymers for advanced technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.61
H-Index - 90
eISSN - 1099-1581
pISSN - 1042-7147
DOI - 10.1002/pat.3308
Subject(s) - materials science , crystallization , copolymer , polystyrene , nucleation , polymer chemistry , chemical engineering , polyethylene , polymerization , supercooling , linear low density polyethylene , phase (matter) , composite material , thermodynamics , polymer , organic chemistry , chemistry , engineering , physics
A m B n miktoarm star copolymers composed of polyethylene (PE) and polystyrene (PS) arms were synthesized by the Pd‐catalyzed hydrogenation of A m B n miktoarm stars consisting of PS and polybutadiene obtained by means of living anionic polymerization. From transmission electron microscopy, it was found that the (PS m )‐ b ‐(PE n ) miktoarm star copolymer samples exhibited more confined morphologies than those expected for their PS‐ b ‐PE linear diblock analogs, a result that indicated more entropic restrictions for chain stretching in the stars. This enhancement in confinement produced by the change in chain topology strongly affected the overall crystallization kinetics of the PE component, especially when it constituted the minor phase. As confinement increased, the supercooling needed for crystallization increased, and the Avrami index was dramatically reduced, since nucleation became the rate‐determining step of the overall crystallization process. Copyright © 2014 John Wiley & Sons, Ltd.