Temperature dependence of polymer crystalline morphology in nylon 6/montmorillonite nanocomposites
Temperature dependence of polymer crystalline morphology in nylon 6/montmorillonite nanocomposites
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DOI：
10.1016/s0032-3861(01)00542-0
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发表时间：
2001-12
期刊：
影响因子：
4.6
通讯作者：
D. M. Lincoln;R. Vaia;Zhi-Gang Wang;B. Hsiao;R. Krishnamoorti
中科院分区：
文献类型：
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作者：
D. M. Lincoln;R. Vaia;Zhi-Gang Wang;B. Hsiao;R. Krishnamoorti
纳米分散的蒙脱土层和工艺历史对尼龙6的晶体结构之间的室温和熔融的影响，同时检查小和广角X射线散射和调制差示扫描量热法。对于所检查的工艺历史，尼龙6从室温到熔融主要表现出α相行为，链-链和片-片间距从100°C到熔融逐渐变化。相比之下，铝硅酸盐层的存在稳定了主要的γ-晶体相，其基本上未改变地持续存在直到熔化。总结晶度和α-和γ-相的相对分数的温度依赖性强烈地依赖于层状硅酸盐含量和尼龙6与铝硅酸盐层之间的相互作用。此外，α-和γ-相的温度依赖性意味着γ-相优先接近硅酸盐层，而α-相存在于远离聚合物-硅酸盐界面区域：通常，工艺历史和使用温度将决定半结晶聚合物纳米复合材料中结晶聚合物相的相对分数，因此在升高的温度下对结晶区的稳定性具有显著的影响。
The influence of nanodispersed montmorillonite layers and process history on the crystal structure of nylon 6 between room temperature and melting is examined with simultaneous small- and wide-angle X-ray scattering and modulated differential scanning calorimetry. For the examined process history, nylon 6 exhibits predominantly α-phase behavior from room temperature to melting, with a gradual shift in chain–chain and sheet–sheet spacings from ∼100°C to melting. In contrast, the presence of aluminosilicate layers stabilizes a dominant γ-crystal phase, which persists, essentially unmodified, until melting. The temperature dependence of the total crystallinity and the relative fractions of α- and γ-phases is strongly dependent on the layered silicate content and the interaction between the nylon 6 and the aluminosilicate layers. Additionally, the temperature dependence of the α- and γ-phases imply that the γ-phase is preferentially in the proximity of the silicate layers, whereas the α-phase exists away from the polymer–silicate interphase region: In general, process history and use-temperature will determine the relative fraction of the crystalline polymer phases in semi-crystalline polymer nanocomposites, and thus have significant influence on the stability of the crystalline region at elevated temperatures.