In this study, polyetherketone was investigated as the high-performance thermoplastic resin for fabrication of carbon fiber reinforced polymer composite.The composites were manufactured by film-fiber stacking process and consolidation by compression molding. The surfaces are modified with different plasma treatment (argon, nitrogen, and air) to overcome the inert nature of carbon fiber surface and subsequent changes were analyzed through atomic force microscopy, X-ray photoelectron spectroscopy, and contact angle measurements. The effectivity of each type of plasma treatment in improvement of the surface-roughness, composition, and wettability were quantified and the subsequent effect on the mechanical properties was demonstrated by measurement of tensile properties and interlaminar shear strength (ILSS). The changes in interfacial morphology of the composite post plasma treatment have been characterized by scanning electron microscopy. From the test results, nitrogen plasma was found to most effective with a 43% increase in mean tensile strength and 25% increase in ILSS when compared to untreated composite.

This work investigates the development of ultra-lightweight, hybrid fireproof composite material. The composite panels are made of 2,5-polybenizimidazole (ABPBI) a thermally stable high-performance fiber and poly ether ketone (PEK) a high-performance film. The surface of ABPBI fiber and PEK film were treated by nitrogen plasma to increase the adhesion characteristics. The composite was fabricated through the stacking method. The hybrid composite was developed by sandwiching silicone rubber foam between surface-treated ABPBI/PEK composite. The entire sample was covered with surface-treated ABPBI fiber using silicone adhesive. The hybrid composite was tested in exposure to dry ice, fire and compression tests. After exposure to fire for 10 min, negligible loss of material was noticed. The Scanning Electron Microscopy (SEM) analysis at the interface indicated strong interfacial adhesion between the PEK matrix and the ABPBI fiber. Limiting oxygen index (LOI) of ABPBI fiber and PEK film appear to be promising in terms of fire resistivity and hence the hybrid composite of PEK/ABPBI sandwiched by silicone foam results one of the best fireproof composite. This composite also shows significant improvement of impact and compressive strength. Analysis under Ansys Fluent software also shows similar results.

This investigation highlights argon plasma treatment on Poly-aryl-ether-ketone (PAEK) and carbon fibre (CF) surface. The PAEK and CF surface is modified for 300 sec and the change in physiochemical and mechanical properties were investigated through Fourier Transform Infrared Spectroscopy (FTIR), Dynamic Contact angle, Atomic Force Microscope (AFM) and Tensile Test. FTIR of surface modified PAEK revealed the stretching of C-H, C=C and C=O functional groups. A reversal phenomenon of increased surface energy was observed through dynamic contact angle study of CF and to further examine the surface energy effect, AFM analysis on CF was carried out revealing increased roughness with numerous micro dents formation. PAEK/CF composite samples were fabricated through compression moulding technique. The change in mechanical properties due to surface modification were analysed through Tensile testing on surface modified PAEK/CF sample and untreated PAEK/CF samples. The surface treated PAEK/CF showed increased tensile strength than untreated PAEK/CF. The argon plasma treatment helped in creating depth striations that lead to better interlocking of resin matrix with the reinforced CF. The fracture surface was examined through Filed Emission Scanning Electron Microscope (FE-SEM) wherein the Micrographs of the tensile tested samples indicated failure of composite due to fibre breakage.

The study involves the processing of a novel poly [1, 4-phenylene-cis-benzobisoxazole] (PBO) fibre reinforced high-temperature thermoplastic composite with polyaryletherketone (PAEK) as the matrix. The PBO fibre and the PAEK film surface was modified using the method of argon and nitrogen plasma treatment. The investigation primarily focuses on evaluating the tensile properties of the fabricated laminates and correlating it with the effect of plasma treatment, surface characteristics, and its fracture surface. A 5% decrease in tensile strength was observed post argon plasma treatment while a 27% increase in strength was observed post nitrogen plasma treatment. The morphology of the failure surface was investigated by scanning electron microscopy and an interfacial failure was observed. Furthermore, the effect of plasma on the wettability of PBO fibres and PAEK film surface was confirmed by the Dynamic Contact Angle analysis and sessile drop method respectively. FTIR spectral analysis was done to investigate the effect of plasma treatment on the chemical structure on the surface. The results of the wettability study showed that the argon plasma treatment of the fibre surface increased its hydrophobicity while nitrogen plasma treatment resulted in the reduction of contact angle.

The objective of this study is to analyze the performance of a blast-proof composite material upon impact loading subjected under blast. The material that is currently being used for blast protection is armored steel. Although it has high strength and toughness its strength to weight ratio is low which limits the applications of armored steel. Hence to overcome this limitation a sandwich composite was considered as an alternative to steel for blast protection. The sandwich composite had the top layer as Ceramic matrix composite to withstand high temperatures, core as a honeycomb structure and bottom layer as polymer matrix composite to stop the core from deforming excessively. The composite was modeled in Abaqus/Explicit and with the help of literature, the blast load was simulated as a triangular pulse in the form of the number of Tri Nitro Toluene (TNT) exploded. The performance of the composite was investigated by analyzing the amount of energy absorbed by the material upon impact and was compared with the performance of armored steel. The results showed that the sandwich composite was able to perform better than or equal to steel up to the explosion of 3 kg of TNT. But beyond 3 kg TNT its performance degrades and becomes lower than steel. Beyond explosion of 3 kg TNT the top layer, Ceramic matrix composite fails which exposes the inner core to the blast environment. As the amount of explosive increases, the core starts to undergo excess deformation and after a certain load, the deformation exceeds the limit of the bottom layer leading to the failure of the polymer matrix composite. Therefore, the proposed sandwich composite performs better than steel within a given working condition but beyond its working condition, its performance degrades resulting in failure of sandwich composite.