Composite material with polyurethane-based reactive hot-melt matrix

Reactive hot-melt resin can form joints with a certain flexibility, high processing speed, high initial rigidity, and high temperature. Such resins can be used to manufacture fiberglass composites because they support a high tensile stress, allow for large strains at low stresses, and have a low density and a working temperature range of −40–110°C. Furthermore, when the mechanical stress is removed, the material returns to its initial condition, as observed in the flexural tests. A polyurethane-based reactive hot-melt resin was characterized by tensile shear tests, Shore hardness tests, differential scanning calorimetry, and thermogravimetry. The contact angles at different temperatures were measured to evaluate the adhesive wettability and to select the best application temperature range of the adhesive, finding the best result at 140 °C. The matrix was characterized at different curing times, and matrix bonding with different adhesive materials was evaluated to provide a greater versatility of applications, to explore new fields of use of this resin as in the matrix of a composite with fiberglass.