PMI foam material is the current development of polymer foam core material. It has many advantages such as low density, excellent high temperature resistance, low dielectric constant and dielectric loss, good fatigue resistance, high voltage strength and specific strength, and it has been widely used. The core material used for composite sandwich structures is widely used in high-speed trains, ships, aerospace and other fields.
Limited by the size and shape of the finished PMI foam, it is inevitable to splice and fill the PMI foam during the integral molding process of the sandwich structure. Existing foamed adhesive materials for honeycomb reinforcement can meet the requirements of low density, high temperature resistance and high strength, but still cannot meet the process requirements of normal temperature splicing and shaping of PMI foam materials.
Although the existing low-density paste adhesive material meets the process requirements of PMI foam material splicing and shaping at room temperature, it cannot achieve the molding process of co-curing with the composite prepreg skin, and its heat resistance cannot meet the design requirements. In this study, alicyclic amines/aromatic amines were used as the compound curing agent. The low-density paste adhesive prepared has the advantages of being spliced and shaped at room temperature, and can be cured and formed at medium and high temperatures, which fully meets the requirements of EP prepreg-PMI Process requirements for autoclave forming of foam sandwich structure.
The adhesive achieves a good balance in density, heat resistance, mechanical properties and process performance, and fills the domestic research gap in this field, and further expands the application range of PMI foam sandwich structures in aerospace and other fields. Has important meaning.