The evolution of electronic communication technology raises higher requirements for low dielectric constant (low-

k

) materials. For this

a benzoxazine functional organosilicon (HP-aptes) with dense Si—O—Si crosslinking networks and large sterically hindered

tert

-butyl groups was prepared by the sol–gel method. Then

a series of polybenzoxazine composites (PPHP) were prepared from intrinsically low dielectric constant bis-functional benzoxazine monomer (P-aptmds) and HP-aptes. The double crosslinking networks of polybenzoxazine and organosilicon further increased the crosslinking density and decreased the dipole density of composites

which endowed the composites with enhanced low-

k

properties. When the content of HP-aptes is 30% (mass)

the crosslinking density was 2.05×10

-3

mol·cm

-3

while that of PP-aptmds was 3.31×10

-3

mol·cm

-3

. In addition

the dielectric constant and dielectric loss of PPHP composite at 1 MHz could reach 2.61 and 0.0056

respectively.