Thermo-mechanical impact of novel 4C3PE-DGEBA/DETA over 4C–DGEBA/DETA carbon fiber laminates with reference to (Type-V) pressure vessel

Abstract Hydrogen storage in lightweight composite pressure vessels demands materials with excellent thermal stability, reliable dimensional properties, and consistent curing behavior. In this study, carbon fiber reinforced epoxy laminates based on 4 carbon fiber layers with epoxy bisphenol A diglycidyl ether and hardener Diethylenetriamine as (4C-DGEBA/DETA) and other with our novel schema of 4 carbon fibers and 3 polyethylene films hot pressed with identical epoxy system as (4C3PE–DGEBA/DETA) analyzed and compared by using thermogravimetric analysis (TGA), Dynamic-mechanical analysis (DMA), and differential scanning calorimetry (DSC). TGA identified the degradation onset and differences in thermal stability between the two systems, while DMA provided insights into temperature-dependent viscoelastic behavior, including stiffness retention and damping characteristics. DSC used to evaluate curing characteristics and glass transition temperatures, revealing links between resin chemistry and thermal performance. The comparison showed that the modified 4C3PE–DGEBA/DETA system exhibited superior thermal resistance and dimensional stability compared to the baseline 4C-DGEBA/DETA composite. These results also improve the understanding of composite behavior in liner-less (Type-V) hydrogen storage pressure vessels and guide material selection and design improvements, supported by SEM surface morphology analysis for a novel 4C3PE laminate geometry.