Novel processable precursor for BN by the polymer-derived ceramics route

Novel precursors polymerized from (alkylamino)borazines (AAB) were synthesized and transformation of processable poly-AAB to boron nitride (BN) was researched. The AAB monomers of the type (BNH)(3)(NHR)(3) were synthesized via ammolysis of 2,4,6-trichloroborazine (TCB) with different propylamines under mild conditions. The specially designed monomers served as molecular precursors for BN by the polymer-derived ceramics route. The processability of the polymeric precursors varied with propylamino-groups of AAB linked with boron atoms on (BNH)(3). The good processability of the poly[2,4,6-tris(iso-propylamino)borazine] (PTP(i)AB) was proven by melt-spinning it into polymer fiber. Furthermore, the PTP(i)AB gave a ceramic yield of about 53 wt% in Ar at 1200 degrees C by TGA. Based on FTIR, Raman, XRD, XPS and elemental analysis, the pyrolytic product of PTP(i)AB showed a composition of BN(1.07). In addition, the BN illustrated excellent oxygen resistance in air. (C) 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved.