Effect of molecular mobility of pre-ordered phase on crystallization in microphase-separated lamellar morphology of strongly segregated crystalline-crystalline diblock copolymers
Effect of molecular mobility of pre-ordered phase on crystallization in microphase-separated lamellar morphology of strongly segregated crystalline-crystalline diblock copolymers
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DOI：
10.1016/j.polymer.2017.02.086
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发表时间：
2017-05
期刊：
影响因子：
4.6
通讯作者：
S. Nojima;Y. Higaki;Katsuhiro Kaetsu;R. Ishige;N. Ohta;H. Masunaga;Tomoyasu Hirai;K. Kojio;A. Takahara
中科院分区：
文献类型：
--
作者：
S. Nojima;Y. Higaki;Katsuhiro Kaetsu;R. Ishige;N. Ohta;H. Masunaga;Tomoyasu Hirai;K. Kojio;A. Takahara
研究了聚乙二醇-聚全氟辛基丙烯酸乙酯嵌段共聚物（PEG-b-PFA-C8）在微相分离片层形态中的等温结晶行为，考察了预结晶相的分子运动性对等温结晶行为的影响。两嵌段共聚物在熔融状态下形成微相分离的层状结构，PFA-C8嵌段的优先结晶提供了层状限制场。反PEG块结晶内的层状限制领域。PFA-C8预结晶相的分子迁移率受到热历史的调制。的结构演变进行了监测的互补组合ofin situtime-resolved同时小角X射线散射/广角X射线衍射测量和热分析。PEG晶体的结晶度和熔融温度与预结晶PFA-C8相的分子流动性有关。高度填充的PFA-C8相（高有序相）限制PEG结晶，而松散填充的PFA-C8相（低有序相）对PEG结晶的限制较弱，从而得到相对有序的PEG晶体。通过调节预结晶相的分子迁移率来控制结晶-结晶嵌段共聚物在限制场中的后续结晶。
The effect of molecular mobility of a pre-crystallized phase on the isothermal crystallization in the microphase-separated lamellar morphology of a strongly segregated crystalline-crystalline block copolymer, poly(ethylene glycol)-block-poly(perfluorooctylethyl acrylate) (PEG-b-PFA-C8), was investigated. The diblock copolymer produced a microphase-separated lamellar morphology in the melt state, and the precedent crystallization of PFA-C8blocks provided the lamellar confinement field. The counter PEG block crystallized within the lamellar confinement field. The molecular mobility of the pre-crystallized PFA-C8phase was modulated by the thermal history. The structural evolution was monitored by a complementary combination ofin situtime-resolved simultaneous small-angle X-ray scattering/wide-angle X-ray diffraction measurements and thermal analyses. The degree of crystallinity and the melting temperature of the PEG crystals were associated with the molecular mobility of the pre-crystallized PFA-C8phase. The highly packed PFA-C8phase (higher-ordered phase) constrained the PEG crystallization, whereas the loosely packed PFA-C8phase (lower-ordered phase) caused a weak restriction in the PEG crystallization to give relatively ordered PEG crystals. Subsequent crystallization in a confinement field of crystalline-crystalline block copolymers was controlled by adjusting the molecular mobility of the pre-crystallized phase.