Rapid Multifunctional Composite Part Manufacturing using Controlled In-situ Polymerization of PA6 Nanocomposite

Abstract

Currently, mass composite manufacturing is dominated by the fiber-reinforced thermosets due to the ease of its processing. However, the addition of multifunctionality to the thermoset composite requires an additional step of manufacturing. This work presents the single-step rapid manufacturing of bespoke designed multifunctional nanocomposite PA6 components. In this method, firstly, the liquid PA6 nanocomposite containing inorganic nano-inclusions was infused into a glass or carbon fibre matrix placed within the mould. Subsequently, the multifunctional composite component was formed via the anionic in-situ synthesis route. The flexibility of this method presented is akin to that of a polymer moulding process, which ensures a reduction in the manufacturing cycle times and increases the production efficiency of the bespoke component. The in-situ reaction is optimised by setting the specific volume of the activator, initiator and including polymer chain terminator, PEG. To prepare the polymer with at least 50% and above crystallinity, the most suitable activator-initiator combination was found to be 0.143 ml and 0.096 ml respectively, with 0.1 g of PEG-6000 for 5 g sample preparation. Such thermoplastic-based components can be easily recycled, present better impact resistance and can be easily formed or fused with heat; eliminating the cost and time associated with the assembly of composite part, unlike thermoset components.