Synthesis and Pyrolysis of Soluble Cyclic Hf-Schiff Base Polymers


Soluble Hf-containing polymers are significant processable precursors for the fabrication of ultra-high temperature ceramics. In this work, cyclic Hf-Schiff base polymers were synthesized via direct polymerization of hafnium alkoxide and bis-salen monomers. The defined structure and molecular weight of the polymers were characterized by NMR spectroscopy, gel permeation chromatography and MALDI-TOF mass spectroscopy. The feed ratio of monomers regulated the molecular weight and solubility of the polymers. This synthetic strategy features simple operation under ambient conditions, efficient reaction with high yield and cyclic polymers as the main products. The Hf-Schiff base polymers were converted to HfC/C materials after pyrolysis under argon at 1600 °C, which was identified by XRD measurements, elemental analyses and Raman spectroscopy. This work will inspire more precise and efficient synthesis and applications of metallopolymers.

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This work was financially supported by the National Natural Science Foundation of China (No. 21604090). The authors are grateful for helpful advices from Lianjun Zheng and Pingxia Zhang on the manuscript.

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Correspondence to Tong Zhao.

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Wu, YH., Ye, L., Sun, YN. et al. Synthesis and Pyrolysis of Soluble Cyclic Hf-Schiff Base Polymers. Chin J Polym Sci (2021).

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  • Hf-containing polymer
  • Schiff base
  • Cyclic polymer
  • Preceramic polymer
  • Hafnium carbide