Journal of Materials Science

, Volume 25, Issue 5, pp 2389–2393 | Cite as

The thermal behaviour of copper diphosphates made by wet process

  • Makoto Watanabe
  • Shigeru Onoda


Copper diphosphates (Cu2P2O7 · 5H2O, Cu1.6K0.8P2O7 · 1.7H2O, and Cu1.5K1.0P2O7 · 2.8H2O) were made by mixing aqueous solutions of tetrapotassium diphosphate and copper dichloride. When the diphosphates were heated, the decomposition of the diphosphates to orthophosphate was observed at a temperature lower than 150° C. The orthophosphate was polymerized by condensation to polyphosphates in the temperature range of about 150 to 450° C. The polyphosphates reorganized to diphosphate at 450 to 550° C according to the following reaction:
$${\text{MO}} - \mathop {\text{P}}\limits_{\mathop {\text{|}}\limits_{\mathop {\text{O}}\limits_{\text{M}} } }^{\mathop {{\text{||}}}\limits^{\text{O}} } - {\text{O}} - (\mathop {\text{P}}\limits_{\mathop {\text{|}}\limits_{\mathop {\text{O}}\limits_{\text{M}} } }^{\mathop {{\text{||}}}\limits^{\text{O}} } - {\text{O}}) - \mathop {\text{P}}\limits_{\mathop {\text{|}}\limits_{\mathop {\text{O}}\limits_{\text{M}} } }^{\mathop {{\text{||}}}\limits^{\text{O}} } - {\text{OM + }}n{\text{MO}} - \mathop {\text{P}}\limits_{\mathop {\text{|}}\limits_{\mathop {\text{O}}\limits_{\text{M}} } }^{\mathop {{\text{||}}}\limits^{\text{O}} } - {\text{OM}} \to {\text{(}}n + 1){\text{ MO}} - \mathop {\text{P}}\limits_{\mathop {\text{|}}\limits_{\mathop {\text{O}}\limits_{\text{M}} } }^{\mathop {{\text{||}}}\limits^{\text{O}} } - {\text{O}} - \mathop {\text{P}}\limits_{\mathop {\text{|}}\limits_{\mathop {\text{O}}\limits_{\text{M}} } }^{\mathop {{\text{||}}}\limits^{\text{O}} } - {\text{OM}}$$
where M stands for 1/2 copper and/or potassium.


Polymer Copper Orthophosphate Potassium 5H2O 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Chapman and Hall Ltd. 1990

Authors and Affiliations

  • Makoto Watanabe
    • 1
  • Shigeru Onoda
    • 1
  1. 1.Department of Industrial ChemistryChubu UniversityAichiJapan

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