Benzoxazine Containing Fluorinated Aromatic Ether Nitrile Linkage: Preparation, Curing Kinetics and Dielectric Properties

Benzoxazine containing fluorinated aromatic ether nitrile linkage (FAEN-Bz) had been synthesized from 2,6-dichlorobenzonitrile, 4,4’-(hexafluoroisopropylidene)diphenol (bisphenol AF), 3-Aminophenol, formaldehyde, phenol by condensation polymerization and Mannich ring-forming reaction. Structures of the monomer were verified by Proton NMR spectrum (1H-NMR) and Fourier transform infrared spectroscopy (FTIR). Curing behaviors and curing kinetics of designed monomers were investigated and discussed. The activation energy was calculated and possible polymerization mechanisms were also proposed. Then, properties of cured polymers including crosslinking degrees, thermal decomposition, surface wettability and energy, and dielectric properties were studied and discussed. Additionally, programmed integral decomposition temperature (IPDT) was also used to evaluate the thermal stability of final polymers. Results indicated that the incorporation of benzoxazine and nitrile resulted in increased thermal stability and char yields. Moreover, the surface wettability and dielectric properties of poly(FAEN-Bz) can be easily controlled by tuning the curing temperatures and time.