Determination of the properties ofThermoplastics by Differential Thermal Analysis

Abstract

The purpose of this research is to use Differential Scanning Calorimetry to find numerous thermal properties of a number of polymer samples. The credibility of the Differential Scanning Calorimetry device to be used was tested using Indium metal as a reference material. Indium was used because its melting temperature is low enough to coincide with the temperature range in which most of the polymer transitions that apply to this research occur. Also, it has a well-defined melting point with an accepted melting temperature and enthalpy of melting of 156oC and 28.5J/g respectively. The values obtained using DSC were 156oC and 21.445J/g, which shows that the enthalpy measurement is off by approximately 25% and the temperature measurements are almost right. The polymers analysed were as follows: 1. Polyethylene (high density) (HDPE) 2. Poly(Vinyl Chloride) high molecular weight (high MW PVC) 3. Poly(Vinyl Chloride) low molecular weight (low MW PVC) 4. Poly(Acrylic Acid) (PAA) 5. Poly(Methyl Methacrylate) (PMMA) 6. Polystyrene 7. Poly(Vinyl Alcohol) (PVA)

As well as the points of melting and enthalpy of melting, found the temperatures of the glass transition for some polymers above (which are available) and attempts were made to explain any deviations from the ideal,such as affected of Poly Acrylic Acid by contaminantsemergence of deviation in the graph at lower temperature.