Thermodynamics of 2-methyltrimethylene urethane, its polymerization in bulk and of poly(2-methyltrimethylene urethane) between 0 and 335 K

Full Paper: In an adiabatic vacuum calorimeter the temperature dependence o f the heat capacity C-p(0) of crystalline 2-methyltrimethylene urethane (MT U; systematic name: 5-methylperhydro-1,3-oxazin-2-one) and of amorphous pol y(2-methyltrimethylene urethane) [PMTU; systematic name: poly(5-methyl-2-ox o-1-oxa-3-azahexamethylene)] was studied between 6 and 335 K with an uncert ainty of about 0.2%. In a calorimeter with a static bomb and an isothermal shield the energies of combustion DeltaU(comb) of the monomer and of the po lymer were measured. From the experimental data the thermodynamic functions C-p(0)(T), H-0(T)-H-0(0), S-0(T), G(0)(T)-H-0(0) were calculated in the ra nge of 0 to 340 K, and enthalpies of combustion DeltaH(comb)(0) and thermod ynamic parameters of formation DeltaH(f)(0), DeltaS(f)(0), DeltaG(f)(0) of the substances studied were estimated at T = 298.15 K and standard pressure . The configurational entropy S-conf(0) of the polymer was estimated. The r esults were used to calculate the thermodynamic characteristics of MTU poly merization in bulk (DeltaH(pol)(0), DeltaS(pol)(0), DeltaG(pol)(0)) with ri ng-opening and formation of linear PMTU in the range of 0 to 340 K.