화학공학소재연구정보센터
Polymer, Vol.175, 302-309, 2019
Thermal responsiveness of hydrogen bonding and dielectric property of polybenzoxazines with different Mannich bridge structures
Variation of hydrogen bonding (HB) and dielectric properties of polybenzoxazines with different Mannich bridge structures at different temperatures are investigated by in-situ Fourier Transform Infrared (FTIR) Spectrometry, perturbation-correlation moving-window two-dimensional (PCMW2D) infrared spectroscopy and Broad Band Dielectric Spectrometer (BDS), respectively. It is found that in phenolic Mannich polybenzoxazine, -OH center dot center dot center dot O HB tends to rearrange into thermally stable -OH center dot center dot center dot N HB. In arylamine Mannich polybenzoxazine, -OH center dot center dot center dot O HB is favorable at relatively low temperature and will dissociate at higher temperature. The PCMW2D infrared spectroscopy reveals that the massive dissociation temperature of -OH center dot center dot center dot O HB occurs is generally higher than 100 degrees C and varies with different polybenzoxazines. The results from BDS suggest that the thermal responsiveness of dielectric properties is closely related to the HB and the thermal resistance of polybenzoxazines. The six-membered -OH center dot center dot center dot N HB is beneficial for high frequency stability and thermal stability of dielectric properties, which makes the phenolic Mannich polybenzoxazine promising candidate as high-temperature dielectric material.