The introduction of graphite into everyday life was something of a revelation. Tennis players using aluminium racquets would describe an almost superhuman feeling when they first used graphite ones. Such was the boost in strength to weight ratios that infusing graphite into any material seemed to create a whole new range of possibilities. Nearly every application – from aerospace, to automation, and of course sports, found that is revolutionised properties in a game-changing way.
Today, graphene – the upgraded version of erstwhile graphite – is being seen in much the same manner. Graphene is a two-dimensional allotrope of carbon that is composed of a single layer of carbon atoms arranged in a hexagonal lattice. It is the strongest material known to mankind and has exceptional thermal and electrical conductivity properties. The unique properties of graphene make it an excellent candidate for enhancing the performance of polymers like PTFE, PEEK, PVDF, and PPS.
Graphene-reinforced polymer composites exhibit superior properties such as high tensile strength, Young's modulus, thermal conductivity, and thermal stability. These enhanced properties make these composites suitable for use in a wider range of applications in various industries.
Polytetrafluoroethylene (PTFE) is a polymer that is widely used in the manufacturing of various industrial products due to its exceptional chemical and thermal resistance. However, its low tensile strength limits its use in applications that require high mechanical strength. The addition of graphene to PTFE can significantly enhance its mechanical properties, making it suitable for use in a wider range of applications. Graphene-reinforced PTFE composites exhibit superior mechanical properties such as high tensile strength, Young's modulus, and wear resistance.
Polyetheretherketone (PEEK) is a high-performance polymer that is widely used in the aerospace, automotive, and medical industries due to its excellent mechanical properties, thermal stability, and chemical resistance. However, virgin PEEK synergises with both carbon and graphite resulting in a high spike in material strength when the materials are mixed and then moulded. The addition of graphene to PEEK can enhance its mechanical and thermal properties even further. Graphene-reinforced PEEK composites exhibit superior thermal and mechanical properties such as high thermal conductivity, tensile strength, and Young's modulus.
Since PEEK, like graphene, is an expensive material, the introduction of graphene does not impact the cost significantly.
The addition of graphene to polymers like PTFE, PEEK, PVDF, and PPS can significantly enhance their mechanical and thermal properties to a great extent, increasing the possibilities of their applications in more demanding environments.
In addition to its mechanical and thermal properties, graphene-reinforced polymers also exhibit excellent electrical conductivity properties. Graphene’s addition to polymers like PTFE, PEEK, PVDF, and PPS can significantly enhance their anti-static properties. Graphene-reinforced composites exhibit high conductivity, low resistivity, and good electromagnetic shielding performance.
The use of graphene in polymers also has environmental benefits. The addition of graphene to polymers can make them more durable and long-lasting. This, in turn, reduces the need for frequent replacements, leading to a reduction in waste and environmental impact.
A common misconception is that graphene is prohibitively expensive and hence not viable to be used commercially. However, commercial grade graphene is presently available for about US$180-200 per Kg. While this is certainly expensive when compared with base materials, such as steel and even lower-grade polymers, there are several use cases with high-performance plastics that allow for the addition of about 5% of graphene. The subsequent enhancement in properties would more than justify the additional cost.
Today, both carbon and graphite are already used in many polymers. It remains to be seen whether the industry slowly shifts to graphene as costs of production reduce and the undeniable improvement in properties are more thoroughly understood.
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