Curing kinetics, thermal, and adhesive properties of acetylene-terminated benzoxazine

摘要

The acetylene-terminated benzoxazine monomer (BB-apa) has been synthesized using 2,2-bis(4-hydroxyphenyl) butane, 3-aminophenylacetylene, and paraformaldehyde. The structure of the monomer was characterized by FTIR spectroscopy and H-1 NMR spectra, which indicated that the reactive oxazine ring and acetenyl groups existed in molecular structure of BB-apa. The polymerization behavior was monitored by FTIR and non-isothermal differential scanning calorimetry (DSC), which showed that the BB-apa had completely cured with multiple polymerization mechanisms according to oxazine ring-opening and ethynyl addition polymerization. The curing kinetics results revealed that the introduction of ethynyl groups can accelerate the ring-opening polymerization of benzoxazine, leading to a lower curing temperature and apparent activation energy. Moreover, the thermoset derived from the BB-apa exhibits higher thermal stability and lap shear strength (at 350 degrees C) with the glass transition temperature of 353 degrees C compared with the traditional benzoxazine polymer without ethynyl groups (BB-a). (C) 2016 Wiley Periodicals, Inc.