Investigation on the effect of multiwalled carbon nanotubes in carbon fiber‐reinforced epoxy composites manufactured using vacuum infusion process and hand layup process followed by vacuum bagging

Hybrid composite's flame retardancy properties play a dynamic role in structural applications. When inorganic nanomaterials form organic/inorganic nanocomposites, they exhibit superior flame‐retardant effects. Therefore, the current work investigates the combined effects of halogen‐free fire‐retardant ammonium polyphosphate (APP) and graphene (GR) nanofillers on the mechanical, and fire‐resistant behavior of hybrid composite fabricated using a vacuum bag process. Mechanical study affirmed that the concurrent incorporation of APP and GR hybrid composite improved the hardness, flexural, and tensile properties by 7%, 26%, and 16%, respectively. Scanning electron microscopy (SEM) confirms that the dispersion of 0.75 wt% GRs improved the mechanical properties by preventing crack propagation and strong binding between fiber‐matrix in the hybrid composite. The vibrational analysis reveals an improved natural frequency (NF) value was obtained with 0.75 wt% GR; further addition of GR increased the damping due to an increase in nanoparticle agglomeration. The combined effect of APP and GR decreased the hybrid composite's water uptake and porosity by 52% and 80%, respectively. The flammability study (Vertical burning) affirmed that the composite's grade score was improved from V‐1 to V‐0. Therefore, the current study emphasizes that this optimized hybrid composite can be utilized in fire‐sensitive structural applications.Highlights UL‐94 VB test reveals the flammability of the hybrid composite. Examine the combined effect of APP and GR in strength and flame‐retardant properties. GR and APP added sample shows better mechanical and flame resistance properties. The optimized wt% of GR and APP for better results is 0.75% and 9.25%. The prepared composite may suitable fire‐sensitive structural applications.

Strength enhancement of a flame‐retardant hybrid composite by incorporating graphene nanoparticles for structural applications

Thiyagu,

NarendraKumar

2024

Effect of hybridization on the mechanical performance and cost efficiency of carbon/flax bio‐hybrid composites

Masud,

Mubashar

2024

This research investigates the effects of fiber hybridization on the mechanical performance of carbon/flax bio‐hybrid laminates. The study comprised of manufacturing and analyzing five distinct composite laminates, comprising pure carbon and various carbon/flax configurations with symmetric and asymmetric layups. The laminates were subjected to uniaxial tensile and low‐velocity impact testing at energy levels from 30 to 75 J. Quantitative and qualitative analyses were conducted to assess the damage/failure patterns to determine the changes due to hybridization and stacking sequence. The experimental results revealed that integrating flax layers into different bio‐hybrid configurations significantly influences their strength, stiffness and impact resistance. One of symmetric layups, having uniform distribution of flax layers throughout thickness, demonstrated the most enhanced performance. To facilitate comprehensive comparison, two indices were developed: Composite‐Performance Index (CPI) and Cost‐Effectiveness Index (CEI). These indices indicate that bio‐hybrid configurations, optimally designed with appropriate number of evenly distributed flax layers, can match or surpass performance of pure carbon layup. The study concludes that incorporating flax into carbon fiber laminates can yield substantial benefits in impact performance with slight compromise in tensile strength and stiffness. However, the overall cost efficiency of bio‐hybrid composites is superior, considering both tensile strength and impact performance.Highlights Effect of fiber hybridization on the mechanical performance of hybrid laminates was studied. Carbon/Flax composites exhibited slightly lower tensile strength compared to carbon‐based layup. Symmetric layups with evenly distributed flax layers showed enhanced impact performance. Cost efficiency of bio‐hybrid composites is superior for both tensile and impact performance.

Effect of molybdenum disulfide functionalized multiwalled carbon nanotubes based hybrid on morphology, mechanical and thermal properties of epoxy nanocomposites

Varghese,

M. S.

2024

Three‐dimensional molybdenum disulfide (MoS2) functionalized MWCNTs hybrid nanoparticles were synthesized using in‐situ hydrothermal reaction. Two types of hybrids, MoS2/MWCNTs‐1 and MoS2/MWCNTs‐2 with MWCNTs to MoS2 precursor weight ratios 1:2 and 1:1 respectively were prepared with varying degrees of hybridization and the effects of their incorporation on tensile strength and fracture toughness properties of epoxies were investigated. Epoxy/MoS2/MWCNTs‐2 nanocomposites showed exceptional mechanical properties due to their improved dispersion, constrained chain mobility and excellent interfacial interactions. MoS2/MWCNTs‐2 nanocomposites showed maximum improvement of tensile strength by 28.52% at 0.5 wt% nanofiller concentration and the highest improvements in fracture toughness by 172% at 0.2 wt% nanofiller concentration. The excellent enhancement of fracture toughness properties was due to the synergic effect of MoS2/MWCNTs hybrid nanoparticles due to the crack pinning and bifurcation properties of MoS2 nanoparticles along with the pull‐out and crack bridging mechanisms of MWCNTs as observed in morphological analysis of fractures nanocomposites. The incorporation of 0.2 wt% of MoS2/MWCNTs‐2 increased the degradation temperatures of epoxy from 591 to 796°C at 95% weight loss due to the improved physical barrier effect.Highlights MoS2/MWCNTs nanoparticles were synthesized using in‐situ hydrothermal reaction 0.5 wt% MoS2/MWCNTs‐2 incorporated epoxies showed highest tensile strength 0.2 wt% MoS2/MWCNTs‐2 incorporated epoxy composites show improved K1c value Incorporation of MoS2/MWCNTs improved the thermal stability of epoxy Synergistic effect of nanocomposite due to crack pinning, bifurcation & bridging