Sequence-Length Segregation during Crystallization and Melting of a Model Homogeneous Copolymer
Sequence-Length Segregation during Crystallization and Melting of a Model Homogeneous Copolymer
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DOI：
10.1021/ma034755c
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发表时间：
2004
期刊：
影响因子：
5.5
通讯作者：
Wenbing Hu;V. Mathot
中科院分区：
文献类型：
--
作者：
Wenbing Hu;V. Mathot
Experiments on the crystallization of ethylene-based copolymers indicate that comonomers tend to be excluded from crystalline regions formed during crystallization of statistical copolymers. 1-3 In a recent publication, 4 we have shown that this behavior can be reproduced in simulations using a simple lattice model for a statistical-copolymer system. The segregation manifests itself as a sequence segregation in homogeneous copolymers and a molecular segregation in heterogeneous copolymers. Nevertheless, it has been suggested that the segregation of monomers and comonomers during crystallization of a statistical copolymer actually reflects a segregation of monomer sequences of different lengths. 5, 6 Possible implications of such sequence-length segregation for crystallization and melting of statistical copolymers have been widely discussed, for example in refs 7-9. We further proposed a pair of master cooling and heating curves of a statistical copolymer that reflect the characteristics of the monomer-sequence-length distribution. 4 However, thus far, there exists no direct experimental information concerning the length segregation during crystallization because it is not straightforward to measure the sequence-length distributions present in the crystalline and amorphous phases. In the present report, we focus our attention on the phenomenon of sequence-length segregation, using the same simulation approach by which the essential features of phase transitions of statistical copolymers have been reproduced.
