Robust Multifunctional Free Standing Polypyrrole Sheet for Electromagnetic Shielding

A multifunctional free standing sheet of polypyrrole has been fabricated using a versatile in-situ chemical polymerization of pyrrole along with carbon fibers followed by thermal curing in the presence of phenolic-novolac resin for the electromagnetic shielding application. Different formulations have been designed in order to optimize the electrical, thermal and mechanical properties. The addition of carbon fibers endows to enhance the electromagnetic interference shielding effectiveness (23 dB) with absorption as the dominant shielding mechanism in the 12.4-18 GHz (Ku-Band) frequency range. This material has strength of 78.96 MPa with an electrical conductivity of 0.034 S/cm and outperforms many other sheet-like materials in stiffness and strength. Its combination of macroscopic flexibility and stiffness is a result of a unique interlocking arrangement of the polypyrrole-carbon fibers with phenolic resin. This work provides a promising methodology to fabricate lightweight polypyrrole-carbon fiber sheet with superior electrical and EMI shielding properties by simultaneously combining the functionality and reinforcement of the polypyrrole.