Zur Frage reversibler thermischer Effekte bei Deformation von Hochpolymeren

Thermodynamic properties of high polymers as a function of their pretreatment as determined by specific heat measurements

“…It is difficult to measure A H inasmuch as it cannot be done directly, because during the drawing process there are both reversible and irreversible heat effects. The liberation or absorption of heat during mechanical cold working has been recently investigated by Mi~ller and coworkers (30,31). However, if the measurements are sufficiently accurate, the difference in enthalpy, /t H, between the cold drawn polymer and the undrawn, either amorphous or annealed, can be calculated from the differences in enthalpy required to bring each form of polymer into a standard state where all forms have the same cnthalpy.…”