The heat capacity of 2-amino-2-methyl-1 3-propanediol was measured from 280 K to its m.p. by means of an automated adiabatic calorimeter. A bifurcated solid-solid transition was found for the compound with the temps. of the max. occurring at 352.89 ?0.01 and 353.72 ?0.01 K. The total enthalpy of the bifurcated transition was determine to be 23.46 ?0.29 kJ/mol, and resolved into the enthalpies of the transitions were determine It may be assumed that there are O-H-O, N-H-O, O-H-N, and N-H-N H bondings in the mols. of 2-amino-2-methyl-1,3-propanediol. The difference in strength between O-H...O and N-H-N bond is considered to be a reasonable explanation of the bifurcated transition.

Key words: PHASE TRANSFORMATION, ENTHALPY, PROPANEDIOL P, CALORIMETRY, SPECIFIC HEAT, BUTANAMINE P