Improved dispersion of reduced graphene oxide in benzoxazine composites via electrostatic interaction with M-cresol

Reduced graphene oxide (rGO) exerts excellent performance in polymers, but suffers from poor dispersion. Here, the electrostatic interaction between the phenolic hydroxyl group of m-cresol and rGO was discovered for the first time, and benzoxazine with m-cresol containing rGO as the phenolic source were synthesized to achieve a more uniform dispersion of rGO in benzoxazine. The results show that the in situ synthesized rGO/benzoxazine system exhibited superior properties, including a lower curing reaction temperature (21°C relative reductions in curing temperature (225.7°C) for the system with 2 wt% rGO added in situ), higher dielectric constant ((8.69) relative improvement of 0.79), higher electromagnetic shielding value at 8.2–12.4 GHz ((7.45 dB) relative improvement of 0.75 dB), and higher thermal diffusivity at room temperature ((0.162 mm 2 /s) relative improvement of 26%). This study provides a method to homogeneously disperse rGO in benzoxazine without using of a solvent or any other treatment.