Investigation of tailored properties of polyphenylene sulfide (PPS) matrix composite reinforced with MWCNT, GNP, H-BN, BNNT

Technological advancements and demanding working conditions challenge the performance limits of materials used today. This situation allows composite materials with advantageous properties to find wide application areas. The properties of composite materials depend on the type of additive material, its proportion, and the applied production method. Reducing the material dimensions to the nanoscale enhances the properties of composite materials by providing a strong phase-interface interaction. Polymer nanocomposites offer various superior properties and many potential application areas due to their unique structures.Polyphenylene sulfide (PPS) has garnered significant attention, especially in the aerospace industry, due to its lightweight, high strength, resistance to high temperatures, easy accessibility, and excellent mechanical and physical properties. In a nanocomposite structure, the mechanical and physical properties of the PPS thermoplastic polymer can be further enhanced by reinforcing it with nanofillers. The homogeneous dispersion of nanofillers within the matrix is crucial for improving mechanical, physical, thermal, and electrical conductivity properties. For this purpose, the PPS polymer was reinforced with multi-walled carbon nanotubes (MWCNT), graphene nanoplatelets (GNP), hexagonal boron nitride (h-BN), and boron nitride nanotubes (BNNT) to enhance its mechanical, physical, and conductivity properties. Composite materials were produced using both hot pressing and injection molding methods, incorporating the nanofillers into the PPS matrix material at different weight ratios.The produced composite materials were subjected to tensile, impact, three-point bending, hardness, DSC, TGA, DMA, SEM analyses, as well as thermal and electrical conductivity measurements. In composite materials, a decrease in mechanical properties was observed due to agglomeration occurring during hot pressing production following mechanical mixing. Regarding thermal conductivity, a 490% increase was achieved with the addition of 10 wt.% GNP, while a 45% increase was observed with 10 wt.% MWCNT. It was found that the electrical conductivity of the semiconducting pure PPS increased by approximately 222% with the addition of 10 wt.% MWCNT at mid-frequencies, rendering it conductive.In composites produced via injection molding, the nanofillers were observed to be homogeneously distributed within the PPS matrix as confirmed by SEM analyses, which was due to prior melt mixing. This homogeneity contributed to improved mechanical properties for all four types of nanofillers. Furthermore, the thermal conductivity significantly increased by 1375% when 10 wt.% MWCNT was added. It was determined that the most suitable production method for carbon- and boron-based nanofiller-reinforced PPS composites is injection molding following melt mixing.