TY - Journal Article AU - Echeverria-Altuna, Oihane AU - Ollo, Olatz AU - Calvo-Correas, Tamara AU - Harismendy, Isabel AU - Eceiza, Arantxa TI - Effect of the catalyst system on the reactivity of a polyurethane resin system for RTM manufacturing of structural composites PY - 2022 PB - Budapesti Muszaki Egyetem, Department of Polymer Engineering AB - The high versatility of polyurethanes (PU’s) is encouraging the development of new formulations for new appli cations, like their use as a matrix for structural composites. PU’s based technology offers some advantages, such as fatigue resistance and fast curing cycles. However, their high reactivity hinders some manufacturing processes like Resin Transfer Moulding (RTM). This work aimed to achieve a PU resin (PUR) formulation with the required latency and reactivity for the RTM. For this purpose, different catalytic systems based on an epoxide and LiCl were investigated. The reactivity of the systems was evaluated through Differential Scanning Calorimetry (DSC) and rheology tests, and the curing reaction and viscosity were modelled. Furthermore, the RTM process of a representative composite part was simulated. Results demon strated the processability improvements when the LiCl was incorporated into the isocyanate component of the formulation combined with a monool or a diol. It was observed that these combinations contribute to the encapsulation of the LiCl between the as formed urethane groups by hydrogen bonding, providing the desired latency and acting as a delayed action catalyst. Once the reaction started and the encapsulation was deactivated, an alkoxide was formed to act as a catalyst. En capsulation was more effective with the diol, providing a higher latency. SN - 1788-618X UR - http://hdl.handle.net/11556/1259 DX - 10.3144/expresspolymlett.2022.19 ER -