Investigation of the properties of carbon fiber, silicon carbide and melamine polyphoshpate reinforced polybutylene terephthalate polymer composites

Polybutylene terephthalate (PBT) is a thermoplastic material that exhibits good mechanical, thermal, and low moisture absorption properties. Polybutylene terephthalate (PBT) based materials play an important role in engineering plastics in many demanding application areas such as vehicle wiring boxes, engine enclosures, under-hood components and more. In recent years, with the advancement of technology, the equipment used in vehicles is expected to have high performance. Various additives added to the polymers significantly increase the thermal and mechanical properties of the material. Making polymer composites thermally conductive has become increasingly important over the last decade, especially to manage thermal issues in electronic products. These polymers are designed to optimize the temperature control of electronic components, conduct and distribute heat effectively. They are known for their lightweight structure and flexibility, and their ability to adapt to different devices. The goal of this research is to investigate the effects of different additives (carbon fiber (CF), silicon carbide (SiC) and melamine polyphosphate (MPP)) on the physical, mechanical and thermal microstructure properties of polybutylene terephthalate materials at various CF and SiC contents (10 wt.%, 20 wt.% and 30 wt.%) and a fixed MP content (17 wt.%). The composites obtained are aimed to be a lightweight and high-performance material alternative that can be used especially in electric vehicles. In this study, PBT hybrid composites were first produced by melting mixing using an extruder. To control the tests to be applied to the produced samples, the test plates were obtained with an injection molding machine, and the morphological, mechanical and thermal properties of these test plates were evaluated. The mechanical test results showed that the tensile strength was increased by adding CF and MPP. The main role of the combined use of CF and MPP was to improve the mechanical properties. Regarding the SiC particles, a decrease in tensile strength was detected with the increase in the SiC content. Moreover, the elongation at break values of the composites increased. However, the opposite effect was observed with carbon fiber (CF). The analysis of scanning electron microscope images of PBT/SiC/CF/MPP composites prepared with various additive ratios showed that the fillers were distributed homogeneously in the PBT matrix without the presence of agglomerations. In summary, since each filler has a different effect, the use of various additives is essential in tailoring the final mechanical properties of PBT composites.