Synthesis and characterization of novel main‐chain benzoxazines containing cycloaliphatic and aliphatic structures and their thermal and dielectric properties.

With the rapid development of ultra‐large‐scale integrated circuits and aerospace, the demand for materials with excellent overall performances is on the rise. In this study, we have successfully synthesized novel main‐chain benzoxazine precursors ((BPA‐AD/dd1)main) containing both cycloaliphatic and aliphatic structures by employing adamantanediamine and Priamine 1074 for the first time, and their chemical structures and polymerization behaviors were characterized using Fourier transform infrared spectroscopy (FT‐IR), NMR spectroscopy (1H‐NMR) and differential scanning calorimetry (DSC). The results showed that the exothermic onset of the (BPA‐AD/dd1)main shifted to lower temperatures with an increasing molar ratio of Priamine 1074. Furthermore, the thermal properties, dielectric properties, surface hydrophobicity, and tensile properties of P(BPA‐AD/dd1)main films were explored via dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), contact angle measuring instrument, an impedance analyzer and universal testing machine. The molar ratio of Priamine 1074 and 1,3‐Bis(4‐anilino)‐adamantane (AD) significantly influenced the thermal properties, dielectric properties, and surface hydrophobicity of P(BPA‐AD/dd1)main. P(BPA‐AD 0.75)main exhibited a high Tg of 296.8°C, excellent dielectric properties (Dk = 2.58 and Df = 0.0055 @ 10 MHz), and large water contact angle as high as 105.8°, qualifying it as a potential candidate for interlayer materials in ultra‐large‐scale integrated circuits and resin matrix in high‐performance composites. [ABSTRACT FROM AUTHOR]