Mechanical and physicochemical performance for recycled CF/PEKKthermoplastic composite materials

The use of the composite materials has recently been increased due to their lightness and high strength. Due to the increasing interest in composite materials, the amount of composite waste accumulated creates a problem for the environment. Therefore, the areas where the collection and incineration processes required for disposal are carried out are not sufficient. For a more sustainable future, the European Union has taken decisions about waste storage and recycling. In addition, various studies have been initiated to increase the use of thermoplastic resin composites, which are recyclable materials. If the necessary studies and infrastructure are not created, there will be a rapid resource consumption and the raw material reserves will gradually decrease. The increase in consumption and the decrease in reserves cause to the danger about the continuity of the sector. In this study, recycled and unprocessed composite materials were compared to reduce the environmental impact of materials during the production phase, reduce economic costs, and ensure product continuity. Carbon/PEKK unidirectional types were consolidated with autoclave curing oven. The samples taken from the final product are mechanical such as bending and interlaminar shear sample (ILSS); It has been tested with physicochemical tests such as differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and fiber void ratio (FVC)-porosity test. The sample was observed under scanning electron microscopy (SEM) to interpret the changes in the structure before and after recycling. All the results obtained were compared with each other and evaluated with the results obtained from the existing studies in the literature. Results indicate that the virgin thermoplastic showed 68.05% higher flexural strength and 7.85% flexural modulus values compared to the recycled thermoplastic composites. the average interlaminar shear strengths were measured as 81.8 MPa and 64.7 MPa for the virgin and the recycled thermoplastic composites, respectively.