Skip to main content
Log in

Synthesis of ceramic precursor polycarbosilane (PCS) under supercritical fluids (SCFs) state

  • Published:
Science in China Series E: Technological Sciences Aims and scope Submit manuscript

Abstract

Using xylene as supercritical fluids (SCFs) media and polydimethylsilane (PDMS) as raw material, the ceramic precursor polycarbosilane (PCS) with moderate molecular weight and narrow molecular weights distribution was synthesized under high pressure and temperature in autoclave. Softening-point test, Fourier transform infrared spectroscopy (FT-IR), gel permeation chromatography (GPC), element analysis and the yield test of PCS were adopted to characterize the SCFs-method and compared with two other PCS synthesis methods named normal-pressure high-temperature (NP) method and high-pressure hith-temperature (HP) method. The results indicate that the PCS maintains a high Si-H content and its chemical formula is SiC1.91H7.27O0.05. The yield is 63.5 wt% which has been improved by about 20 wt%, the softening-point is 180–220°C, the number average molecular weight is 1477 and the molecular weights distribution index is 1.61. The synthesis method via supercritical fluids with good diathermancy and reaction uniformity is a new feasible method of synthesizing PCS with good qualities.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. Herzog A, Thunemann M, Vogt U, et al. Novel application of ceramic precursors for the fabrication of composites. J Euro Ceram Soc, 2005, 25: 187–192

    Article  Google Scholar 

  2. Yajima S, Hayashi J, Omori M, et al. Development of a SiC fibers with high tensile strength. Nature, 1976, 261: 683–685

    Article  Google Scholar 

  3. Song Y C, Wang L, Feng C X. The molecular weight distribution and spinability of polycarbosilane. High Techn Lett, 1996, 1: 6–10

    Google Scholar 

  4. Xue J G, Chu Z Y, Feng CX, et al. Synthesis PCS through PDMS pyrolysis and rearrangement. J National Univ Defense Techn, 2001, 5: 36–41

    Google Scholar 

  5. Cheng X Z, Song Y C, Xie Z F. Synthesis of polycarbosilane from polydimethylsilane at high temperature and high pressure. Mater Eng, 2004, 8: 39–45

    Google Scholar 

  6. Reverchon E, Adami R. Review nanomaterials and supercritical fluids. J Supercritical Fluids, 2006, 37: 1–22

    Article  Google Scholar 

  7. Yeo D, Kiran E. Formation of polymer particles with supercritical fluids: A review. J Supercritical Fluids, 2005, 34: 287–308

    Article  Google Scholar 

  8. Yao Y B, Xie T, Gao Y M. Handbook of Physico Chemistry. Shanghai: Shanghai Science and Technology Publishing Company, 1985. 1131

    Google Scholar 

  9. Song Y C, Yao S, Feng C X, et al. A study on the pyrolysis of polydimethylsilane. Acta Polym Sin, 1995, 12: 753–757

    Google Scholar 

  10. Fritz G, Grobe J, Kummer D. Carbosilanes. Advan Inorg Chem Radiochem, 1965, 7: 349–418

    Article  Google Scholar 

  11. Yajima S, Hasegawa Y, Hayashi J. Synthesis of continuous silicon carbide fiber with high tensile strength and high Young’s modulus. Part I Synthesis of polycarbosilane as precursor. J Mater Sci, 1978, 13: 2569–2576

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to DaXiang Yang.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Yang, D., Song, Y. & Li, Z. Synthesis of ceramic precursor polycarbosilane (PCS) under supercritical fluids (SCFs) state. Sci. China Ser. E-Technol. Sci. 51, 1445–1450 (2008). https://doi.org/10.1007/s11431-008-0108-7

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11431-008-0108-7

Keywords

Navigation