Performance of Graphite Filled Composite Based on Benzoxazine Resin. II. Decreasing the Moulding Time of the Composite

摘要

To put the fuel cell to practical use, it is necessary to reduce its cost for the production of the bipolar plate as one of the components in the cell. Decreasing the moulding (cure) time of the graphite filled composites as a bipolar plate can increase its productivity. In this study, we aimed to decrease the moulding (cure) time of graphite-filled composites based on benzoxazine resin for the bipolar plate. Therefore, phenol novolac resin was added to benzoxazine resin as a curing accelerator. Expanded graphite was used for the preparation of the graphite-filled composites. The composites were prepared by means of the compression moulding of mixtures of graphite and benzoxazine resin containing phenol novolac as a curing accelerator. The properties of the graphite filled composites based on benzoxazine resin containing phenol novolac as a curing accelerator were characterised by mechanical properties, gas permeability and electrical conductivity. As a result, the curing reaction of benzoxazine resin containing phenol novolac as a curing accelerator could proceed more rapidly than that of only benzoxazine resin, and the moulding (cure) time of the composite was decreased. It was found that phenol novolac was an effective moulding accelerator of the graphite filled composites based on benzoxazine resin, and that it could increase the productivity of the bipolar plate using the graphite filled composite based on benzoxazine resin. It was also found that graphite filled composites based on benzoxazine resin containing phenol novolac as a curing accelerator showed good gas impermeability, electrical conductivity and mechanical properties compared with those of the graphite-filled composites based on the conventional phenolic resins.