Manufacturability and performance of nano enhanced fiber reinforced polymeric composites.

摘要

Fiberglass reinforced polymeric composite materials (FRPC), have been widely used in automotive, mobiles phones cases, wind blades and sports equipment. FRPC advantages include low specific gravity, high internal damping, high strength to weight ratio, and high modulus to weight ratio. However, since the main load barer is the long fiber reinforcement while the polymer matrix provides shape and stiffness, failure at the interface between the matrix and the fibers or in the matrix itself, will decrease the mechanical properties of the composite.;One approach to reinforce the matrix is to add nanoparticles to the composite material. Due to their small size, nanoparticles become part of the matrix and thus provide reinforcing to the matrix phase. These materials are referred as Nano enhanced Fiber Reinforce Polymeric Composites. This approach combines the benefits of polymer nanocomposites with the inherent strength characteristics of conventional FRP, where the nanoparticles would address the matrix failure. Advantages of fiber reinforced polymer nanocomposites include customizable properties for special applications (such as increased thermal conductivity and surface abrasion resistance); disadvantages include safety concerns and lack of processability. The critical issue becomes how to successfully achieve incorporation of the nanoparticles into the FRP in a robust, affordable, and scalable process, while keeping an adequate processability.;In this study, two different glass mats were used one of them was Windstrand, a stitched equally-biaxial R-glass fabric and the other was Advantex, a unidirectional glass fiber mat. Both of them were provided by Owens Corning. The mats were sprayed with carbon nanofibers (CNF) on both sides. Mechanical properties of composites manufactured via vacuum assisted resin transfer molding (VARTM) were measured. Permeability, of the sprayed glass mats was measured as an indication of processability. Bulk mechanical properties are improved while permeability decreases with the addition of CNF.;Another way of using nanoparticles is for surface protection and to provide a conductive surface for applications that require EMI shielding and sand erosion resistance. CNF nanoparticles can be pre-sprayed onto a carbon veil to make a very thin film or nanopaper. The nanopaper can then be placed on top of the fiber preform in VARTM process. Elongation to break, fatigue, surface erosion resistance and EMI shielding effectiveness of the composite were improved using nanopaper enhanced FRPC. In order to evaluate processability of nanopaper enhanced FRPC, permeability of the nanopaper was measured through two different methods. With the data of permeability of nanopaper and fiber preform, FEM model was built up to compare with visualization experiments.