The thermal analysis of polymers at high pressures

The extension of two techniques of thermal analysis into the region high pressures (50–100 MPa) are discussed. One is the extension of dilatometry (thus becoming pressure-volume-temperature measurements, PVT). This technique has been well established over the past few years. Some results obtained on typical polymer systems are presented and discussed. The second is the extension of the differential thermal analysis (DTA) principle to high pressures, trying to maintain some of the advantages of the DTA technique when compared to the PVT method, such as small sample size and productivity. DTA determinations of the pressure dependence of the melting points of pure metals and polymers are presented and compared with results from the PVT technique. Satisfactory agreement is obtained. The advantages and limitations of our current high-pressure DTA method are discussed.We gratefully acknowledge the partial financial support of the high-pressure DTA development by Metler Instrumente AG, Switzerland.