heat capacity

Poly(-N-butyl--L-aspartate) (PANBLA) is nylon-3 derivative in which an alcoxycarbonyl group has been stereoregularly attached to -carbon of the repeating unit. Like poly(-isobutyl--L-aspartate) (PAIBLA) exists in two helical forms, namely hexagonal form (13/4 helix) and tetragonal form (4/1 helix), were characterized by X-ray diffraction. The hexagonal form appears to be poorly crystalline and it could not be obtained well oriented. On the other hand tetragonal form turns to be highly crystalline.

On the basis of literature data the constancy of heat capacity change during vaporization ( 2 %) and sublimation ( 8 %) has been determined at 298 K for different organic compounds. The obtained equations allow to recalculate the enthalpy according to Kirchhoff’s law easier compared with present techniques based on the increments method. The vaporization and sublimation enthalpies of 5-(2-nitrophenyl)-furan-2-carbaldehyde have been determined and recalculated for 298 K for the reliability proofing of the suggested method.