Chemo-rheological optimization of hot-melt epoxy resin systems for shape memory polymer smart prepregs

Shape memory polymer prepregs are a type of smart composite material that combines shape memory functionality with pre-impregnated fibre reinforcements. A novel diglycidyl ether of bisphenol A (DGEBA) based resin matrix with integrated shape memory effect was systematically developed as a suitable resin system for the manufacturing of hot-melt prepregs. Neopentyl glycol diglycidyl ether (NGDE) was integrated to enhance the shape memory performance of DGEBA while minimizing the effect on thermal and mechanical properties. The resin formulation, including resin content, latent curing agent and accelerator amounts, was determined through chemo-rheological analysis. Isothermal curing revealed 70 ℃ as the optimum resin impregnation temperature for prepreg manufacturing. Neat SMP epoxy exhibited tensile strength of 37.8 MPa, while the SMP prepregs exhibited resin content of 46% and excellent tack properties. The curing kinetics was performed using the modified Kamal-Sourour method, achieving a higher correlation ( R 2 of 0.9965), and validated across a wide dynamic heating range (1 to 25 ℃/min). The system demonstrates shape memory performance with over 98% shape recovery and 95% shape fixity, and combines high-temperature curing capability and extended pot-life, offering significant advancement over conventional prepreg technology through the development of smart prepregs for civil and aerospace engineering applications.