Comparative analysis on fatigue,creep,DMA,and flammability behavior of carbon nanotubes,onion peel extracted carbon quantum dots,and Kevlar fiber reinforced epoxy composite

Abstract

Biocomposite material are now gaining attention in recent decades, by reinforcing waste biomass as filler, and this will attribute to reduce the agro waste generating pollution as well as creating sustainable products. The present research study aim is to perform a thorough analysis of multiscale polymer composite using onion peel-derived carbon quantum dots (CQDs) and compare them to carbon nanotubes (CNTs) in polymer composite. Furthermore, Kevlar fiber is used to provide further reinforcement on hybrid composites. Using an abrasive water jet machine, test specimens are carefully sectioned from the composite plates then, rigorous adherence to ASTM standards is followed for the subsequent characterization, which covers features such as flammability, fatigue, creep strain, and dynamic mechanical analysis (DMA). The findings reveal that the composite designation which combines 2 vol.% CQDs with 35 vol.% Kevlar, and epoxy matrix (EKCQ3), exhibits higher fatigue strength. The EKCQ3 shows a 5.6% improvement in 25% UTS, 12.9% improvement in 50% UTS, and 8.7% improvement in 75% UTS fatigue counts when compared to composite designation with 2 vol.% of CNTs. This demonstrates the CQDs composite’s improved fatigue performance. In a similar way, the CQDs in composite produce less creep strain. In particular, with time intervals of 2000, 4000, 6000, 8000, and 10,000 s, the EKCQ3 shows creep strain values of 0.0022, 0.0031, 0.0046, 0.0065, and 0.0085. The composite designation exhibits improved mechanical performance as seen by its high storage modulus of 8.2 GPa in relation to DMA characteristics. All composite designations are flame-retardant in terms of flammability, and flame propagation speeds range from 5 to 9 mm/min. Thus over all, this study underscores a promising potential of CQDs in advancing composite materials for diverse applications in super capacitors, shielding of microwaves and lightweight automotives.