Synthesis and Thermal Behavior of New Precursors for B-C-N Ceramics

Three new borazine derivatives, 2,4,6-tri(allylamino)borazine (CH2=CHCH2NHBNH)3 (1), 2,4,6-tri(3-ethynylanilino)borazine (CH≡CC6H4NHBNH)3 (2), and 2,4,6-tri(4-propargyl oxyanilino)borazine (CH≡CCH2OC6H4NHBNH)3 (3) were synthesized by reaction of 2,4,6-trichloro-borazine Cl3B3N3H3 (TCB) with corresponding primary amines, respectively. Their thermal behavior was studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). These molecules were easily crosslinked via thermal polymerization of reactive ethynyl or vinyl groups. The pyrolytic residues of borazines were investigated by X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (XRD), and scanning electron microscopy (SEM). The analytic results indicated that B-C-N ceramics were formed upon pyrolysis of the borazines under an inert atmosphere.