| In the recent years, many investigators have attempted use of nanomaterials to enhance mechanical properties of composite structures. The present work outlines the role of nanomaterials in the improvement of mechanical properties of polymeric composites. In particular, the current work is focused on the development of nanoengineered prepregs. Since delamination is the most critical problem for the laminated composite materials, the current study only focuses on the development of nanoengineered prepregs as a possible solution to alleviate delamination problems in laminated composites. Curing characteristics are one of the most important process parameters in the development of various polymer applications including prepregs. For optimum properties of the prepreg, it is very crucial that the exact degree of cure has been ensured. To obtain a certain degree of cure, during the prepreg fabrication, it is mandatory to know the cure kinetics of the material system. Fiber reinforced composites typically consist of two materials and show significant variations in cure behavior with a minor difference in material compositions. To enhance the performance of composite materials, in addition to the resin and conventional fibers, usually, electrospun nanofibers are used in the fabrication of nanoengineered prepregs. However, change in cure kinetics due to the addition of nanofiber layer is not fully explored. In the current research, the effect of electrospun carbon nanofiber mats on the curing profile of the Epon862-W system is investigated. The cure profiles were obtained by different isothermal scans using differential scanning calorimeter. The obtained data is fitted with nth order polynomial and using an acceleration reaction model. The chemical parameters such as activation energy, reaction orders have been estimated. Based on the estimated deviation (for cure estimation) from the experimental values, it is observed that for nanoengineered Epon 862-W resin system, acceleration model is sufficient to describe the cure behavior. Using this cure kinetics model, nanoengineered prepregs comprising of carbon nanofibers and plain weave carbon fabric infused with Epon 862-W were successfully fabricated and characterized to obtain the mechanical properties. It has also been observed that with the addition of nanofiber the fracture toughness of the short beam coupons shows higher values in a polymer matrix carbon composites. |
