Graphene Polyurethane nanocomposite: Duel enhancement of barrier and mechanical properties

Sivan Peretz Damari, Chemical Engineering, Ben Gurion University, Beer-Sheva, Israel
Oren Regev, Chemical Engineering, Ben Gurion University, Beer-sheva, Israel


Polymer based nanocomposites (PNC) have become a prominent area of current research and development. Reduction in polymer permeability is both fundamentally important and a practical necessity in the polymer industry. The barrier properties of polymers can be significantly altered by inclusion of impermeable lamellar fillers with sufficient aspect ratio to alter the diffusion path of gas-penetrant molecules. The most common barrier material encountered in the PNCs literature is clay. However, clays are much less efficient for reducing water vapor permeability since they absorb water and swell, consequently degrading other properties of the PNC such as the mechanical strength. In this study we focused on graphene nanoplatelets (GNPs) as barrier fillers. The tremendous interest in graphene lies in its one-atom-thick nature, with a densely packed conjugated structure that is capable of exhibiting unprecedented electrical, thermal, and mechanical properties. In addition, high aspect ratio (l/d > 1000) graphene are known to be impermeable to most gases and liquids, much like clay, making them of great interest for the preparation of barrier PNCs. However, only limited amount of data is available on the barrier properties of GNP-loaded PNCs compared to clay-loaded PNCs. This study focuses on the permeability and mechanical properties of GNP-loaded polyurethane through bulk films, and the effect of the GNP concentration on the barrier properties.