Manufacturing functionalized mono-crystalline diamond containing electrospun fibers reinforced epoxy composites with improved mechanical characteristics

Official URL: http://dx.doi.org/10.1016/j.diamond.2017.04.018

Diamond in polymeric composites provides superior mechanical and thermal properties due to its controllable surface chemistry and large accessible surface area. Homogeneous dispersion of diamond in matrix and improved interfacial bondings between diamond and matrix are two important issues to achieve high performance and prevent structural failures in composite manufacturing. In the present work, the surface of submicron scale mono-crystalline diamond was functionalized by hydrazine hydrate and then dispersed in polymethyl methacrylate (PMMA) matrix homogenously by electrospinning technique. This process circumvented aggregations of diamond particles and provided homogeneous dispersion in polymer matrix. Structural morphologies of diamond reinforced PMMA electrospun fibers were adjusted by tailoring polymer concentration, diamond content, flow rate and applied voltage to attain an ideal fiber structure having continuous network without beads. PMMA was used as a polymeric carrier to improve the bonding interactions with epoxy matrix. Flexural tests indicated that the addition of 1 wt% functionalized diamond based electrospun fiber in epoxy matrix improved flexural modulus by 36.4% and flexural strength by 28.1%. Therefore, controlling the surface chemistry of diamond provides better interfacial interactions in reinforcing agent and thus load transfer was realized efficiently in epoxy specimen. In addition, thermal stability of epoxy composites was improved by the addition of diamond particles in electrospun structure.