Über die druckabhängigkeit der viskoelastischen und physikalisch-chemischen eigenschaften von polymeren, 2. Spezifisches volumen und thermische ausdehnung einiger polymeren beim schmelzen und kristallisieren

Measurements of specific volumes are described as function of temperature and pressure of melting or crystallizing linear polyethylene, isotactic polypropylene, and polyoxymethylene. A pressure range of 50 to 1600 bar permits determination of relative volume changes as function of temperature and pressure. Pressure influence on melting points, temperature hysteresis between melting and crystallization and their volume changes as well as the thermodynamic driving force of phase change have been investigated. Clausius-Clapeyron's equation permits calculation of heats of crystallization.