ABSTRACT

Polyurethane (PU) composites were prepared with different diisocyanate and diol compounds by adding cobalt ion-based polyoxometalate (Co-POM) as reinforcement. For the determination of using potential in microelectronic applications, the dielectric behavior and dielectric constant of these PU composites were investigated and compared to pure polyurethane structures. For this aim, firstly, Co-POM with Keggin structure was obtained from ammonium heptamolybdate, 1,10-phenanthroline ligand and a cobalt (II) salt by hydrothermal synthesis technique. Then, polyurethane/Co-POM composites (PU/Co-POM) were prepared with ethylene glycol, nonaromatic diisocyanate and different amounts of Co-POM reinforcement (1%, 3%, 5% and 10%, w/w) by in situ polymerization and mix-blend technique. Obtained PU/Co-POM composites were characterized in detail by infrared spectroscopy, Elemental Mapping, Energy-dispersive X-ray spectroscopy (EDX) and X-ray powder diffraction (XRD) spectroscopy. The surface structure, morphology and roughness of PU/Co-POM composites were investigated by SEM and AFM analysis. The elemental maps of the PU/Co-POM surface were examined by EDX elemental mapping analysis methods. Thermal stability, Tg values and thermal decomposition temperatures of PU/Co-POM structures were determined by different thermal analysis techniques. Thermal analysis results showed that the PU/Co-POM composites are thermally stable up to approximately 200°C and Tg values of synthesized PU composites are seen between 54.72°C and 75.15°C. The dielectric properties and dielectric constants of the PU/Co-POM composites were determined in the frequency range 1 Hz to 1000 kHz at room temperature using impedance analyzer. Dielectric constants of these composites were ranged from 5.50 to 9.26 according to their polarizability and H-bonding ability of PU matrix structure. According to the dielectric measurements, the dielectric constants of the PU/Co-POM structures were significantly decreased compared to the pure PU structures.

摘要

通过添加钴离子基多金属氧酸盐（Co-POM）作为增强剂，用不同的二异氰酸酯和二醇化合物制备聚氨酯（PU）复合材料。为了确定在微电子应用中的使用潜力，研究了这些PU复合材料的介电性能和介电常数，并将其与纯聚氨酯结构进行了比较。为此，首先通过水热合成法从七钼酸铵，1,10-菲咯啉配体和钴（II）盐中获得具有Keggin结构的Co-POM。然后，用乙二醇，非芳族二异氰酸酯和不同量的Co-POM增强材料（1％，3％，5％和10％，w / w）制备聚氨酯/ Co-POM复合材料（PU / Co-POM）。原位聚合和混合共混技术。通过红外光谱，元素图谱，能量色散X射线光谱（EDX）和X射线粉末衍射（XRD）光谱对获得的PU / Co-POM复合材料进行了详细表征。通过SEM和AFM分析研究了PU / Co-POM复合材料的表面结构，形貌和粗糙度。通过EDX元素映射分析方法检查了PU / Co-POM表面的元素映射。通过不同的热分析技术确定PU / Co-POM结构的热稳定性，Tg值和热分解温度。热分析结果表明，PU / Co-POM复合材料在高达约200°C的温度下具有热稳定性，并且合成PU复合材料的Tg值在54.72°C至75.15°C之间。使用阻抗分析仪在室温下在1 Hz至1000 kHz的频率范围内确定PU / Co-POM复合材料的介电性能和介电常数。这些复合材料的介电常数在5.50至9.26之间，这取决于它们的极化率和PU基体结构的H键结合能力。根据介电测量，与纯PU结构相比，PU / Co-POM结构的介电常数显着降低。