High pressure resin transfer moulding of epoxy resins from renewable sources

Automotive composite applications are increasingly growing due to demand for lightweight structures to comply with the stringent CAFE and EU ELV for fuel reduction. Electric or hybrid cars needs weight saving approaches to compensate for the added weight of battery systems. The recent developments of processing methods like HP-RTM (High-Pressure Resin Transfer Moulding), CRTM (Compression Resin Transfer Moulding) and SnapCure Prepreg technology is pushing the use of composites for mass production due to their short processing times combined with part performances comparable to autoclave technology. HP-RTM, for example, is the preferred production technology for the BMW i3 life module. The key aspects of HP-RTM are the short injection times (i.e., less than 1 min) and the fast curing of the thermoset resins (i.e., less than 10 min). The shortcoming of most HP-RTM commercial resins is the limited choice of recycling techniques. The standard recycling solution is incineration, but this solution poses some concerns in terms of global environmental impact. Novel solutions have been developed to overcome this limitation based on the use of recyclable epoxy systems. In this chapter, the results of experimentation carried out by our group with ammines by Connora Technologies and bioepoxy resins by Entropy Resins will be discussed