Mechanical performance of graphenex/poly(ether ketone ketone) composite sheets by hot pressing

Abstract

Polymer composites are gradually replacing traditional metal materials in the fields of aviation, aerospace, automotive and medicine due to their corrosion resistance, light weight and high strength. Moulding technology and organization morphology of polymer composite are key elements affecting the quality of products and their application, so a vacuum hot pressing process for graphenex/poly(ether ketone ketone) (PEKK) (x = 0%, 2%, 3%, 4%, 5%, 6%) composite powders is explored with particularly designed moulding parameters to achieve high conductive properties and good mechanical properties in graphene/PEKK composite sheet with thickness of 1.25 mm and diameter of 80 mm. The vacuum environment ensures that the graphene is not oxidized by air during hot pressing molding, which is essential for achieving conductive property in the graphene/PEKK composite; The hot pressing temperature of each graphene/PEKK composite powder is higher than glass transition temperature but lower than melting temperature, which ensures the graphene/PEKK composite powders is fully compacted and then graphene is fully lapped in the composite sheet. In addition, the graphene/PEKK composite sheet shows conductive property when the graphene content increases to 3wt%, and then the conductivity of the composites increases and then decreases with a peak value at 5wt% with increasing graphene content. By comparing the mechanical properties and microstructure morphology of the graphene/PEKK composite sheets, it was obtained that graphene content has an obvious effect on the mechanical properties of the composites, e.g., the mechanical properties will be increased as the graphene content increasing when graphene content is more than 3%. The graphene distribution law of the composite material with different graphene contents is analysed using a scanning electron microscope (SEM).

Polymer-based graphene composite molding: a review

“…Injection molding is a process that heats and melts polymers, metals, and other materials and uses pressure to inject them into the mold for cooling molding. 34,35 H. Massé et al 34 included an overview of the injection molding process, the primary characteristics of the ow patterns during lling that were relevant to bre orientation, and a review of experimental observations of bre orientation in injection-molded parts, 25 Injection molding 4 1.8 26 --PEEK 26 Selective laser sintering 0.5 3.15 107 7.7 × 10 −9 -PEEK 27 Hot pressing molding 3 3.07 106.2 0.1 -PEKK 28 Spark plasma sintering 5 --16.4 -PEKK 29 Hot pressure molding 2 3.07 186 --PEKK 30 Electromagnetic molding 3.8 ----including bre orientation around weld lines. Finally, an outline of modeling techniques used in the prediction of bre orientation in injection molding is presented.…”

“…During the sintering process, it is oen necessary to add auxiliary materials to speed up the discharge of impurities and gas from the compact billet. 27,29 The sintered body obtained by hot pressing sintering has ne grains and a uniform distribution, with a density of more than 96%, and the pressure is generally 30-50 MPa. 40 Quanbin Wang et al 29 utilized hot pressing to process graphene/PEKK composite slabs with different graphene contents in their work and carried out tensile strength tests on the formed plates.…”

2D MOFs and Zeolites for Composite Membrane and Gas Separation Applications: A Brief Review

“…Considering the cases of graphene/polymer composites and nanoclay/polymer composites, it is well-known that 2D materials can enhance polymer mechanical properties due to several reasons, such as their high intrinsic strength and stiffness, large surface area for improved interactions, barrier effects on chain movement, reinforcement at the nanoscale, flexibility for better bonding, fracture toughness improvement, and reduced polymer chain mobility. − Therefore, it is rational to expect that zeolite or MOF nanosheets will also have similar effects on polymers, while the degree of enhancement must be lower than that with graphene due to the lower mechanical properties of zeolites and MOFs compared with graphene. , In addition, the enhancement is highly dependent on the properties of the polymer. For example, polyimide has much stronger mechanical properties than rubbery polymers, while both polymers can be used depending on the target gas pair …”

Computer Simulation of Composite Materials Behavior under Pressing

“…Pressing and sintering are the main technological operations in powder metallurgy [ 1 ]. Traditional and modified types of these operations are sufficiently studied for various classes of powder and composite materials with the help of experimental studies, which are highlighted in many works [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ]. For example, Wang Q.B.…”

“…For example, Wang Q.B. et al [ 2 ] established the optimal parameters of the hot vacuum pressing process for obtaining a polymer composite material based on poly(ether ketone ketone) with high conductive and mechanical properties. The review [ 3 ] summarized the theoretical and practical research results on cold sintering processes used for various materials.…”