화학공학소재연구정보센터
Thermochimica Acta, Vol.440, No.2, 188-194, 2006
Thermodynamic properties of carbosilane dendrimers of the third to the sixth generations with terminal butyl groups in the range from T -> 0 to 600 K
In the present work temperature dependences of heat capacity of carbosilane dendrimers with butyl terminal groups of the third and the fourth generations as well as of the fifth and the sixth generations have been determined first in the range from 6 to 340 K and between 6 and 600 K, respectively, by precision adiabatic vacuum and dynamic calorimetry. In the above temperature ranges the physical trans formations have been detected and their thermodynamic characteristics have been estimated and analyzed, The experimental data were used to calculate standard thermodynamic functions, namely the heat capacity C-p(o)(T), enthalpy H-o(T)-H-o(0), entropy S-o(T)-S-o(0) and Gibbs function G(o)(T)-H-o(T), for the range from T -> 0 to (340-600) K. Linear dependences of changing the corresponding thermodynamic functions of the dendrimers on their molecular weight and the number of butyl groups on an outer sphere have been determined. (C) 2005 Elsevier B.V. All rights reserved.