PE Crystallinity by DSC
Near this problem will be attached some data sets as ASCII (text) files. One of them will show a DSC
melting and/or cooling curve for a standard, such as indium metal. You will be given the mass of the
indium. The other DSC trace will show the melting and/or cooling of polyethylene, and you will be given
the mass of PE.
1. Plot the results and determine the melting temperature, Tm. In case you have both heating and
cooling curves, it is better to get the Tm from the heating curve (why?).
2. If you have cooling curves, it is better to determine the heat of fusion from them, rather than
the heating curve (why?).
3. Use the two curves to determine the percent crystallinity of the polyethylene, assuming 100%
PE has a heat of fusion of 69 cal/g, AND DESCRIBE HOW YOU DID IT.
Grading criteria
Temperatures of In and PE transitions: 30%
PE Crystallinity: 50%
Description how you did it: 10%
Estimated uncertainty in PE Crystallinity: 10%