Development of graphene and boron nitrate-based polymeric systems for electrical applications

本研究计划的一般主题是开发用于电气应用的聚合物基系统。几十年来，功能性介电和半导电聚合物基材料确实用于电力应用。这些应用范围从电力电缆、高压电容器、大型旋转机器的绝缘壁的绝缘材料，到导体和绝缘屏的半导体材料和外部电晕保护涂层，以及用于应力分级应用的聚合物基复合材料已被发现在用作电阻应力分级材料时是有效的。这类材料还具有许多优点，如成本低，可在工业规模上加工，并且可以使用分子添加剂或增强纳米颗粒（通常是无机的）来定制其电学，机械和热性能。下一代电工设备的发展，如直流传输基础设施，部分依赖于具有特定性能的新型介电系统的发展。对空间电荷积累的电阻在交流应用中不需要，但在高压直流（HVDC）应用中至关重要，这是过去完全被忽视的新要求的一个例子，但在未来将是相关的。本研究计划旨在研究和优化几种类型的聚合物纳米复合材料（PNC）的介电和电气应用。本研究计划研究的第一个系统是基于石墨烯的聚合物系统，它现在正逐渐成为经济上可行的纳米复合材料，因为大规模生产的石墨烯现在是可用的（实际上最大的供应商之一是一家加拿大公司），这使得该产品以合理的成本在工业规模上很容易获得。这些复合材料的应用范围从极低浓度高压直流电缆的绝缘系统，到浓度在渗透阈值附近的电阻应力分级系统，再到浓度高于渗透阈值的半导电系统。与传统的炭黑负载聚合物相比，这些系统有许多优点，但在广泛商业化的含石墨烯器件出现之前，仍需要进行大量的开发和优化。本研究计划研究和优化的第二个系统是环氧硝酸硼纳米管（BNNT）系统，该系统在许多需要平衡性能的应用中是很有前途的材料，例如良好的绝缘性能和高导热性，这通常是矛盾的。机器绝缘、储能电容器和干式高压电容器以及航空航天应用是这些材料系统的一些潜在利基。

The general topic of this research proposal is the development of polymer-based systems for electrical applications. Functional dielectric and semi-conductive polymer-based materials are indeed used since decades for electrical power applications. These applications extend from insulating materials for the insulation walls in power cables, high voltage capacitors, large rotating machines, to semiconducting materials for conductor and insulation screens and outer corona protection coatings, as well as for stress grading applications for which polymer-based composites have been found to be effective when used as resistive stress grading materials. This class of materials also features many advantages such as low cost, processability at the industrial scale and the possibility to tailor their electrical, mechanical and thermal properties with either molecular additives or reinforcing nanoparticles, usually inorganic. The development of next-generation electrotechnical apparatus, such as DC transmission infrastructures, relies in part on the development of new dielectric systems with specific properties. Resistance to space charge accumulation, which is not required for AC applications but critical for High Voltage DC (HVDC) applications, is an example of new requirement that was completely ignored in the past but will be relevant in the future. This research proposal will aim to investigate and optimize the properties of several types of polymeric nanocomposites (PNC) for dielectric and electrical applications. The first system that will be investigated in this research proposal is graphene-based polymeric systems that are now slowly becoming economically viable nanocomposites since mass produced graphene is now available (actually one of the biggest provider is a Canadian company) which makes this product readily available at the industrial scale at a reasonable cost. The application of these composites ranges from insulating systems for HVDC cables at very low concentration, to resistive stress grading systems at concentration in the vicinity of the percolation threshold up to semi-conductive systems for concentration above the percolation threshold. There are many advantages to these systems compared with conventional carbon black loaded polymers but there is still a lot of development and optimization needed before the appearance of widespread commercialized graphene-containing devices. The second system that will be investigated and optimized in this research program are epoxy Boron Nitrate NanoTubes (BNNT) systems that are promising material for many application where a balance of properties are needed such as good insulating properties and high thermal conductivity, which usually is contradictory. Machine insulation, energy storage capacitors and dry-type high voltage capacitors as well as aerospace applications are some potential niche for these material systems.