石墨烯纳米片(GNP)的作用,浓度为1、5和10重量%时,通过差示扫描量热法(DSC)和实时X射线衍射实验研究了聚醚醚酮(PEEK)复合材料的熔体结晶和冷结晶过程。DSC结果揭示了GNP的双重作用:(a)在较高温度下从熔体开始结晶的成核作用和(b)由于聚合物链移动性的限制而导致的较长的整体结晶时间。纳米复合材料的流变行为证明了这种受阻的流动性,因为复杂粘度的增加,G\',具有GNP含量的G″,以及在高GNP含量的复合材料中发现的非牛顿行为。最后,实时宽角度小角度同步加速器X射线辐射(WAXS/SAXS)X射线测量表明,GNP没有影响PEEK的正交相,也没有影响结晶过程中晶相的演变。然而,通过WAXS获得的晶体的相关长度和通过SAXS获得的长周期(L)根据GNP含量而变化。
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.