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Thermodynamic Properties of the Carbosilane Dendrimer of the Sixth Generation with Terminal Trimethylsilylsiloxane Groups

  • N. N. Smirnova,
  • S. S. Sologubov,
  • A. V. Markin,
  • S. A. Milenin,
  • E. A. Tatarinova,
  • A. M. Muzafarov

摘要

Abstract

The temperature dependence of the heat capacity of the sixth generation carbosilane dendrimer with terminal trimethylsilylsiloxane groups was determined by high-precision adiabatic vacuum calorimetry in the temperature range 6–318 K and differential scanning calorimetry in the range 300–600 K. Anomalous changes in the heat capacity were discovered in the range T = 179–200 K due to devitrification of the dendrimer and in the range 380–450 K due to the nanoscale effect characteristic of dendrimers of high generations. The thermal stability of the compound was studied by thermogravimetric analysis, and the temperature of the start of thermal destruction was found to be 600 K. The experimental data obtained were used to calculate the standard thermodynamic functions of the dendrimer for the range from T → 0 to 600 K for various physical states, as well as the standard entropy of its formation in the devitrified state at T = 298.15 K.