Fabrication of carboxyl nitrile butadiene rubber composites with high dielectric constant and thermal conductivity using Al2O3@PCPA@GO hybrids

Owing to excellent adhesion and easy process, dopamine has been widely used as an intermediate for adjusting the molecular structure of nanoparticles . However, the high cost of dopamine largely impedes its large-scale applications. Herein, alumina@poly(catechol-polyamine)@graphene oxide (denoted as Al 2 O 3 @PCPA@GO) multilayer core-shell hybrids were prepared via poly(catechol-polyamine) (PCPA) modification. The as-prepared hybrids were added into the carboxyl nitrile butadiene rubber (XNBR) latex to produce composites with high thermal conductivity because of the strong interaction between polar groups in Al 2 O 3 @PCPA@GO core-shell hybrids and C N groups in XNBR matrix. Finally, the maximum thermal conductivity (0.48 W/mK) was obtained with 30 vol% Al 2 O 3 @PCPA@GO/XNBR composite, which was about three times of pure XNBR matrix (0.16 W/mK). Moreover, 30 vol% Al 2 O 3 @PCPA@GO composite showed a high dielectric constant (16.84 at 100 Hz) and low dielectric loss tangent (0.45 at 100 Hz). Besides, the 30 vol% Al 2 O 3 @PCPA@GO/XNBR composite displayed a high tensile strength of 11.86 MPa, which is an advantage for practical applications. The developed method has a shorter reaction time and lower cost compared with poly(dopamine) coating, suggesting potential applications as thermally conductive materials for electronic equipment.