Study of two novel siloxane-containing polybenzoxazines with intrinsic low dielectric constant

Abstract

The new generation of high-speed and low-loss electronic equipment requires the dielectric constant and dielectric loss of materials to be as low as possible. In this paper, two novel siloxane-containing benzoxazine monomers P-aptmds (1,3-bis(3-(6-(tert-butyl)-3,4-dihydro-2H-1,3-benzoxazine-3-yl)propyl)-1,1,3,3-tetramethyldisiloxane) and P-appdms (1,3-bis(3-(6-(tert-butyl)-3,4-dihydro-2H-1,3-benzoxazine-3-yl)propyl)-polydimethylsiloxane) with different lengths of dimethylsiloxane segments were successfully synthesized. It was noted that PP-appdms had excellent thermal stability due to the long dimethylsiloxane segments. Compared with PP-aptmds, the surface free energy and water absorption of PP-appdms was significantly lower. The static water contact angle of PP-appdms was 111.2° and the surface free energy was only 13.37 mN/m2. Due to the presence of bulky tert-butyl groups and non-polar siloxane segments, both PP-aptmds and PP-appdms showed good dielectric properties with dielectric constant of 2.82 and 3.09 respectively.