Agrisuelas Jerónimo, Balart Rafael, García-Jareño José J, López-Martínez Juan, Vicente Francisco
Laboratory of Electrochemistry, Department of Physical Chemistry, University of Valencia, C/Dr. Moliner 50, E-46100 Burjassot, Spain.
Instituto Universitario de Investigación de Tecnología de los Materiales (IUITM), Universitat Politècnica de València (UPV), E-03801 Alcoy, Spain.
Materials (Basel). 2024 May 24;17(11):2527. doi: 10.3390/ma17112527.
Elastic composites were prepared using a procedure involving hot plates and zinc powder that was directly dispersed into an EVA matrix. The correlation between the zinc content and the conductive properties of the material was studied via impedance spectroscopy, the thermal properties of the material were studied via differential calorimetry and the mechanical properties of the composites were studied via tensile strength curves, representing an important advancement in the characterization of this type of composite material. The composites' tensile strength and elongation at break decrease with the addition of filler since zinc particles act as stress-concentrating centres, while the composites' hardness and Young's modulus increase because of an increase in the stiffness of the material. The perturbation across the EVA/Zn composites was characterized using an RC parallel equivalent circuit that allowed us to easily measure their resistivity (ρp) and permittivity (εp). The dependence of these electrical magnitudes on the zinc content is correlated with their mechanical properties across the characteristic time constant τp = ρp·εp of this equivalent circuit. The dependence of the mechanical and electrical magnitudes on the zinc content is consistent with the formation of percolation clusters. The addition of graphite particles increases their potential performance. Three possible mechanisms for the electrical transport of the ac-perturbation across the EVA/Zn composites have been identified. Chemical corrosion in acid media causes the loss of zinc surface particles, but their bulk physical properties practically remain constant.
采用一种涉及热板和直接分散在EVA基体中的锌粉的方法制备了弹性复合材料。通过阻抗谱研究了锌含量与材料导电性能之间的相关性，通过差示量热法研究了材料的热性能，并通过拉伸强度曲线研究了复合材料的力学性能，这代表了这类复合材料表征方面的一项重要进展。由于锌颗粒充当应力集中中心，添加填料后复合材料的拉伸强度和断裂伸长率降低，而由于材料刚度增加，复合材料的硬度和杨氏模量增加。使用RC并联等效电路对EVA/Zn复合材料的扰动进行了表征，这使我们能够轻松测量其电阻率(ρp)和介电常数(εp)。这些电学量对锌含量的依赖性通过该等效电路的特征时间常数τp = ρp·εp与它们的力学性能相关联。力学和电学量对锌含量的依赖性与渗流簇的形成一致。添加石墨颗粒提高了它们的潜在性能。已经确定了EVA/Zn复合材料上交流扰动的电传输的三种可能机制。酸性介质中的化学腐蚀导致锌表面颗粒损失，但其整体物理性能实际上保持不变。
