Chemically Derived BN Ceramics: Extensive ¹¹B and ¹⁵N Solid-State NMR Study of a Preceramic Polyborazilene

Abstract

Polyborazilene, a precursor for hexagonal boron nitride (h-BN) ceramics, has been extensively characterized by 15N and 11B MAS NMR. The various B and N sites have been identified according to their first neighboring atoms as well as to the second ones in the case of 15N and have also been quantified. This study demonstrates that a suitable choice of NMR techniques together with the use of isotopic enrichment can lead to a large improvement in spectral resolution, which allows better understanding of such complex BN preceramic polymer structures.