I've been trying to study the degree of crystallinity of Polypropylene using DSC. In the heating curve I find two melting peaks - one at around 150 and the other at 160 degree Celsius. I think the peak at 160 C is due to isotactic PP but I don't find any reason for the 150 peak. Is this an error of some sort or an artifact?
Also, the baseline will have a positive slope for the 2nd heating. Is it right?