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首页> 外文期刊>Journal of Non-Crystalline Solids: A Journal Devoted to Oxide, Halide, Chalcogenide and Metallic Glasses, Amorphous Semiconductors, Non-Crystalline Films, Glass-Ceramics and Glassy Composites >Molecular dynamics of poly (oxybutylene)s confined in pores of Vycor glass
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Molecular dynamics of poly (oxybutylene)s confined in pores of Vycor glass

机译：局限在Vycor玻璃孔中的聚氧化丁烯的分子动力学

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We have investigated the relaxation dynamics of poly (oxybutylene), POB, chains of various lengths, with different end groups (OH and CH3) in bulk and in confinement using dielectric relaxation spectroscopy. It is known that POB chains exhibit, apart from the segmental (main) relaxation process, the dielectric normal mode process which reflects the global chain motions. The comparative study of OH- and methyl-ended POB chains in bulk reveals the marked effect of association of hydroxyl end groups and indicates that the decrease in the density of the methylated specimens results in the acceleration of both relaxation processes, main and normal mode relaxations. For the confined POB chains the data indicate that the segmental relaxation process becomes faster (the effect being more pronounced for the methylated POB chains). A decrease in T-g of about 8 K for the methyl- and 2 K for OH-ended POB chains is estimated. Regarding the average relaxation rates of the normal mode process our data indicate that global chain mobility is not affected by the confinement. (c) 2007 Elsevier B.V. All rights reserved.
机译：我们使用介电弛豫光谱技术研究了在不同长度的聚（氧丁烯），POB，不同长度的链，具有不同端基（OH和CH3）的弛豫动力学。众所周知，POB链除了分段（主）弛豫过程外，还表现出反映整体链运动的介电正态过程。 OH和甲基末端POB链的大量比较研究显示了羟基端基缔合的显着效果，并表明甲基化样品密度的降低导致弛豫过程，主模式和正模式弛豫的加速。对于受限的POB链，数据表明节段松弛过程变得更快（对于甲基化POB链，这种影响更为明显）。估计甲基末端的T-g下降约8 K，OH末端的POB链下降约2K。关于正常模式过程的平均松弛率，我们的数据表明全局链的移动性不受约束的影响。 （c）2007 Elsevier B.V.保留所有权利。

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