Alvaredo Ángel, Martín María Isabel, Castell Pere, Guzmán de Villoria Roberto, Fernández-Blázquez Juan P
IMDEA Materials Institute, C/ Eric Kandel 2, 28906 Getafe, Madrid, Spain.
FIDAMC, Foundation for the Research, Development and Application of Composite Materials, Avda. Rita Levi Montalcini 29, Tecnogetafe, 28906 Getafe, Madrid, Spain.
Polymers (Basel). 2019 Jan 12;11(1):124. doi: 10.3390/polym11010124.
The effect of the graphene nanoplateletets (GNP), at concentration of 1, 5 and 10 wt %, in Poly ether ether ketone (PEEK) composite crystallization from melt and during cold crystallization were investigated by differential scanning calorimetry (DSC) and real time X-ray diffraction experiments. DSC results revealed a double effect of GNP: (a) nucleating effect crystallization from melt started at higher temperatures and (b) longer global crystallization time due to the restriction in the polymer chain mobility. This hindered mobility were proved by rheological behavior of nanocomposites, because to the increase of complex viscosity, G', G″ with the GNP content, as well as the non-Newtonian behavior found in composites with high GNP content. Finally, real time wide and small angle synchrotron X-ray radiation (WAXS/SAXS) X-ray measurements showed that GNP has not affected the orthorhombic phase of PEEK nor the evolution of the crystal phase during the crystallization processes. However, the correlation length of the crystal obtained by WAXS and the long period (L) by SAXS varied depending on the GNP content.
通过差示扫描量热法（DSC）和实时X射线衍射实验，研究了浓度为1%、5%和10%的石墨烯纳米片（GNP）在聚醚醚酮（PEEK）复合材料从熔体结晶以及冷结晶过程中的作用。DSC结果显示GNP具有双重作用：（a）成核作用，熔体结晶从更高温度开始；（b）由于聚合物链迁移率受限，整体结晶时间延长。纳米复合材料的流变行为证明了这种迁移率受阻，因为随着GNP含量增加，复数粘度、储能模量（G'）、损耗模量（G''）增大，且在高GNP含量的复合材料中发现了非牛顿行为。最后，实时宽角和小角同步加速器X射线辐射（WAXS/SAXS）测量表明，GNP既未影响PEEK的正交相，也未影响结晶过程中晶相的演变。然而，通过WAXS获得的晶体相关长度和通过SAXS获得的长周期（L）随GNP含量而变化。
