Grafting strained alkenes to milled carbon fibre for use in polydicyclopentadiene

The use of carbon fibre for reinforcement in polymers has been a subject of increased interest within research in recent years, with carbon fibre composites being prevalent in many fields including, aerospace, automotive and military. However, many carbon fibre composites suffer from a common fault of matrix adhesion, the bond between the carbon fibre reinforcement and the polymer it is held within. Fibre matrix adhesion can lead to detrimental mechanical properties - therefore, it is of interest to be able to increase fibre matrix adhesion benefiting both the mechanical properties and reducing the limitations on the possible uses for carbon fibre reinforced composites.Carbon fibres possess a stereotypically non-reactive surface and this is the primary reason for the lack of carbon fibre to matrix adhesion.This project aims to create an ultra-high strain rate, impact resistant, carbon fibre reinforced polymer, and in doing so simultaneously address the issue of carbon fibre’s non-reactive surface that hinders fibre matrix adhesion, whilst establishing a baseline for the production of polydicyclopentadiene and carbon fibre composites.The first step began with a baseline study on the synthesis of polydicyclopentadiene, as it was required for the creation of the controls, as well as establishing safe handling practices for the material. Several improvements were made to standard handling practices, and the process refined for rapid sample creation.Next was the task of modifying the surface chemistry of carbon fibres, to better improve bonding between the carbon fibre and the polymer matrix. This was achieved via the careful selection of molecules to be converted into diazonium salts and then grafted onto the surface of the fibre. The synthesis of these compounds was achieved in high overall yield (82.67% over 5 steps) and (81.29% over 3 steps) and were then successfully grafted to carbon fibres, confirmed by XPS. The aim being the interaction of grafted molecules with the dicyclopentadiene as if it, itself, was part of the polymer, allowing for increased matrix adhesion to be achieved.Lastly, combining both the polydicyclopentadiene and the modified carbon fibre a carbon fibre composite was created. The results presented a composite, that is harder/more brittle in comparison to samples without the modified carbon fibre.