Preparation of polybenzoxazine/resorcinarene composites with low dielectric constants

A series of polybenzoxazine (PBZ)/resorcinarene composites with low dielectric constants were prepared by the thermal curing of a siloxane‐containing benzoxazine (P‐aptmds) with C‐methylcalix[4]resorcinarene (CMCR). CMCR with active hydroxyl groups could serve to lower the thermal curing temperature of P‐aptmds. The results of differential scanning calorimetry (DSC) showed that the peak exothermic temperature of P‐aptmds decreased from 262°C to 192°C. The introduction of CMCR increased the crosslinking density of the PBZ/CMCR composites and improved the thermal properties. Due to the incorporation of CMCR with macrocyclic structure, the dielectric constant and the dielectric loss of the PBZ/CMCR composite could be reduced to 2.63 and 0.0055 at 1 MHz, respectively. Moreover, the PBZ/CMCR composites possessed good hydrophobicity and low water absorption. This approach was expected to provide a facile design strategy of low dielectric composite materials.