Cross‐Linking via Electron Beam Treatment of a Tailored Polysilazane (ABSE) for Processing of Ceramic SiCN‐Fibers

Cost‐efficient ceramic SiCN fibers were produced by the precursor route consisting of four processing steps: synthesis of the polymer, melt‐spinning, curing via electron beam (e‐beam) and subsequent pyrolysis at 1100°C in a nitrogen atmosphere. A special solid and meltable fiber polymer, the so‐called polycarbosilazane ABSE has been developed for this purpose, which is easily curable by e‐beam. In this article the influence of the curing dose and the molecular weight of the used precursor on polymer cross‐linking are discussed. The degree of cross‐linking of the e‐beam treated precursor ABSE is characterized by the gel fraction and the pyrolysis behavior. The gel fraction increases with the e‐beam dose as well as with higher molecular weight of the used precursor fraction. By an optimal adjustment of the e‐beam dose on the molecular weight of the precursor the curing treatment leads to unmeltable polymer fibers at reduced costs as well as to an improved flexibility of the green fibers which is very important for the continuous pyrolysis process to ceramic fibers.

Keywords:

• Precursor ceramic
• SiCN‐fibers
• Radiation curing
• Gel fraction

Acknowledgments

The technical assistance of Beta Gamma Service Company for carrying out the curing by e‐beam is thankfully appreciated.

Thanks to the staff members of the chair Keramische Werkstoffe und Bauteile of the University of Bremen for measurement the mechanical properties of the fibers.