Nature of the Sub-Rouse Modes in the Glass−Rubber Transition Zone of Amorphous Polymers
Nature of the Sub-Rouse Modes in the Glass−Rubber Transition Zone of Amorphous Polymers
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DOI：
10.1021/ma102897e
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发表时间：
2011-04
期刊：
影响因子：
5.5
通讯作者：
Xuebang Wu;C. S. Liu;Zhen-Gang Zhu;K. Ngai;Li-Min Wang
中科院分区：
文献类型：
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作者：
Xuebang Wu;C. S. Liu;Zhen-Gang Zhu;K. Ngai;Li-Min Wang
高分子量无定形聚合物的玻璃-橡胶转变或软化区的剪切机械柔量通常从10 - 10 cm 2/dyn的玻璃态柔量增加到10 - 6 cm 2/dyn的橡胶态平台。从本地段松弛和劳斯模式的贡献不能占整个范围内的遵守，离开三十年的遵守之间的贡献不明。虽然新的粘弹性机制，称为子劳斯模式的长度尺度之间的局部节段松弛和劳斯模式已被发现，以填补空白，到目前为止，他们还没有被发现在原型聚合物，包括聚苯乙烯（PS）和聚（甲基丙烯酸甲酯）（PMMA）。这就对子劳斯模式存在的普遍性提出了质疑。利用高精度剪切力学光谱仪，观测了聚苯乙烯和聚甲基丙烯酸甲酯中的亚劳斯模。从确定的子劳斯模式的各种属性，我们发现…
The shear mechanical compliance of the glass−rubber transition or softening zone of high molecular weight amorphous polymers typically increases from the glassy compliance of ∼10−10 cm2/dyn up to the rubbery plateau of ∼10−6 cm2/dyn. The contributions from the local segmental relaxation and the Rouse modes cannot account for the entire range of compliance, leaving three decades of compliance in between their contributions unaccounted for. Although new viscoelastic mechanism called sub-Rouse modes with length scales intermediate between the local segmental relaxation and the Rouse modes have been found to fill the void, so far they have not been found in archetypal polymers including polystyrene (PS) and poly(methyl methacrylate) (PMMA). This calls the generality of the existence of sub-Rouse modes into question. Using high precision shear mechanical spectroscopic tool, we report the observation of the sub-Rouse modes in PS and PMMA. From the various properties of the sub-Rouse modes determined, we find th...