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为改善石墨烯(Gra)在聚偏氟乙烯(PVDF)中的分散性和界面性质,以甲基丙烯酸甲酯(MMA)和1-乙烯基-3-乙基咪唑溴盐(IL)为单体合成P[MMA-IL]共聚物,用于修饰石墨烯(Gra),并通过溶液共混、热压法制备PVDF/PMMA、PVDF/P[MMA-IL]、PVDF/PMMA/Gra和PVDF/P[MMA-IL]/Gra复合薄膜.采用Raman光谱、场发射扫描电子显微镜(FESEM)、傅里叶变换反射红外光谱分析仪(FTIR-ATR)、X射线衍射仪(XRD)、偏光显微镜(POM)、示差扫描量热仪(DSC)和电感电容电阻测试仪(LCR)对复合薄膜的结构形态、结晶与介电行为进行表征和分析.Raman光谱表明P[MMA-IL]与Gra之间存在强相互作用;FESEM照片显示P[MMAIL]能够促进Gra在基体中的分散;DSC、XRD和FTIR-ATR数据表明PMMA降低PVDF的结晶温度,PMMA和Gra未能诱导出?-PVDF极性晶体,而单独的P[MMA-IL]会通过咪唑阳离子-偶极子作用诱导?-PVDF晶体;通过咪唑阳离子-π强相互作用,P[MMA-IL]在模板剂Gra表面进行修饰,协同诱导作用增强.POM照片表明?-PVDF晶体在生长过程中,MMA链段会嵌入到球晶的晶片空隙中,引起结构疏松;离子-偶极子和IL成核作用导致?-PVDF晶体尺寸较小,结晶较快.介电行为研究表明PMMA及其修饰Gra降低PVDF的结晶度和链浓度,导致界面极化和取向极化较弱,介电响应较弱;而P[MMA-IL]修饰Gra诱导的?-PVDF晶体、以及IL链段在界面的离子极化使得界面极化作用增强,介电响应增强.
In order to improve the dispersibility and interfacial properties of graphene in polyvinylidene fluoride (PVDF), methyl methacrylate (MMA) and 1-vinyl-3-ethylimidazolium bromide The P [MMA-IL] copolymer was synthesized and used to modify graphene. PVDF / PMMA, PVDF / P [MMA-IL], PVDF / PMMA / Gra and PVDF were prepared by solution blending and hot pressing / P [MMA-IL] / Gra composite films were characterized by Raman spectroscopy, field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR- ATR), X-ray diffraction (XRD) (POM), differential scanning calorimetry (DSC) and inductive capacitance resistance tester (LCR) were used to characterize and analyze the morphology, crystallization and dielectric behavior of the composite films.Raman spectroscopy showed that P [MMA-IL] FESEM photos show that P [MMAIL] can promote the dispersion of Gra in the matrix; DSC, XRD and FTIR-ATR data show that PMMA reduces the crystallization temperature of PVDF, PMMA and Gra can not induce the -PVDF polarity Crystal, while P [MMA-IL] alone induces the -PVDF crystal through imidazolium cation-dipole interaction. The interaction of P [MMA-IL] Line modification and synergistic induction.POM photographs show that the MMA segments intercalate into the spherulites in the voids of the spherulites during the growth of? -PVDF crystals, resulting in the loose structure; the ion-dipole and IL nucleation lead to? PVDF crystals are smaller in size and faster in crystallinity.Research on dielectric behavior shows that PMMA and its modified Gra reduce the crystallinity and chain concentration of PVDF, resulting in weaker interfacial polarization and orientation polarization and less dielectric response; while P [MMA -IL] modified Gra-induced? -PVDF crystals, as well as the ion polarization of the IL segment at the interface, enhanced the interface polarization and enhanced the dielectric response.