High dielectric, low curing with high thermally stable renewable eugenol‐based polybenzoxazine matrices and nanocomposites

Abstract

ABSTRACTIn the present work, a new type of bio‐based benzoxazines were prepared by using aniline, N, N‐dimethyl amino propyl amine (DMAPA) and caprolactam modified DMAPA with eugenol. The benzoxazines resulted were characterized for their molecular structure by Fourier transform infrared and nuclear magnetic resonance spectroscopy. The polymerization process of benzoxazines and their thermal behavior were studied by differential scanning calorimetry and thermogravimetric analysis, respectively. Moreover, the effect of chemical blending of the synthesized benzoxazines with conventional benzoxazines [bisphenol A benzoxazine (BPAb) and bisphenol F benzoxazine (BPFb)] and bismaleimide was studied to bring down the polymerization temperature by creating supplementary potential sites for polymerization. Furthermore, to reduce the polymerization temperature, the benzoxazines synthesized in the present study were partially incorporated with 10 wt % of catalysts (4‐hydroxy phenylmaleimide, 4‐amino phenol, and 4‐hydroxy acetophenone). The graphene reinforced polybenzoxazine composites were also prepared by incorporating varying weight percentages (1, 3, 5, 7, and 10 wt %) of graphene oxide to obtain hybrid nanocomposites. From the results obtained, it was observed that the polymerization temperature (Tp) was significantly reduced (more than 31 °C) in both the cases of blends of conventional BPAb and BPFb. It was also observed that the values of the dielectric constant of graphene reinforced hybrid composites are significantly enhanced. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47050.