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Hierarchical structures formed by partially crystalline polymers in solution: from fundamentals to applications – a combined conventional, focusing and ultra‐small‐angle neutron scattering study
Author(s) -
Schwahn Dietmar,
Radulescu Aurel,
Stellbrink Jörg,
Fetters Lewis J.,
Richter Dieter,
Kentzinger Emmanuel
Publication year - 2007
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s0021889806053507
Subject(s) - neutron scattering , copolymer , wax , small angle neutron scattering , polymer , materials science , scattering , small angle x ray scattering , small angle scattering , neutron diffraction , melting point , chemical physics , chemical engineering , crystallography , polymer chemistry , crystal structure , optics , chemistry , composite material , physics , engineering
Multilevel aggregates with characteristic sizes covering four orders of magnitude, from 1 nm to 10 µm, are formed upon cooling decane solutions of poly(ethylene‐butene) random copolymers (designated as PEB‐ n , where n is the number of ethyl side branches per 100 backbone C atoms) and wax‐containing mixed solutions. The partially crystalline PEB‐7.5 copolymers form two distinct morphologies that evolve on a range of length scales. When these polymers are mixed with wax molecules having a crystallization point lower than the polymer aggregation temperature, a hierarchy of morphologies evolves on decreasing the temperature. The multilevel structures were elucidated by combining conventional small‐angle neutron scattering, focusing small‐angle neutron scattering and ultra‐small‐angle neutron scattering investigations with microscopy. Contrast‐matching analysis of the wax and copolymer components within the common morphologies revealed the wax‐crystal modification capacity of the PEB‐7.5 copolymers. Since the copolymers limit the growth of wax crystals, they are potential pour‐point depressants for the fuel industry.