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Thermodynamics of 2,2‐dimethyltrimethylene carbonate, of its bulk polymerization process and of poly(2,2‐dimethyltrimethylene carbonate) from 0 to 470 K at standard pressure
Author(s) -
Lebedev Boris V.,
Kulagina Tat'yana G.,
Telnoy Vadim I.,
Vasil'ev Valery G.
Publication year - 1995
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.1995.021961105
Subject(s) - thermodynamics , heat capacity , isothermal process , polymerization , chemistry , polymer , adiabatic process , calorimetry , calorimeter (particle physics) , standard enthalpy of formation , enthalpy , glass transition , polymer chemistry , materials science , organic chemistry , physics , detector , optics
In the present work the thermodynamic properties of 2,2‐dimethyltrimethylene carbonate (DTC) and poly‐2,2‐dimethyltrimethylene carbonate (PDTC) were studied by precise calorimetry. In adiabatic and dynamic vacuum calorimeters the temperature dependence of the heat capacity of DTC and PDTC was studied between 5 and 470 K. Temperature and enthalpies of physical transitions were determined, and in an isothermal calorimeter energies of combustion of the above compounds were measured. From the results the thermodynamic functions C p 0 ( T ), H °( T )– H °(0), S °( T ), G °( T )– H °(0) were calculated for various physical states of the monomer and the polymer from 0 to 470 K. The standard enthalpies of combustion and thermochemical parameters of formation Δ H f 0 , Δ S f 0 , Δ G f 0of the objects studied were estimated at T =298,15 K and p = 101,325 kPa. The zero entropy S gl 0 (0) and configurational entropy S conf 0of PDTC in the glassy state and the difference in zero enthalpies of the polymer in the glassy and crystalline states H gl 0 (0)– H cr 0 (0) were estimated. The results were used to calculate the thermodynamic parameters of the bulk polymerization of DTC (Δ H pol 0 , Δ S pol 0 , Δ G pol 0 ) in the range of 0 to 420 K. It was established that for the process DTC → PDTC, Δ G pol 0< 0 if the polymer is crystalline and Δ G pol 0> 0 in the case of amorphous PDTC (glassy or liquid). The ceiling temperature is T c 0= 500 K.