Thermodynamics
posted by Tracy .
I am doing a lab and there is one question I can't get. We have the enthalpy of fusion of crystalline polyeythlene, mass, onset temperature and energy required for a phase change of both low density polyethylene and high density polyethylene. They as to calculate the percent crystallinity of both by calculating the fraction of crystalline polymer in the samples. I really have no clue how to go about this I'm stumped. Any help would be greatly appreciated. Thanks.

I realize that you have posted this question once before and got no responses. I regret that I am not able to answer it. I am hoping that another teacher will be able to help you.
I did try "googling" the words <crystalline polyethylene fusion> and came up with several references, some of which you might find helpful. I suggest that you try doing the same, if you haven't already. 
You might find chapter 5 of this book on polyethylene properties useful:
http://books.google.com/books?id=OPuWyxwJwJwC&pg=PA177&lpg=PA177&dq=crystalline+polyethylene+fusion&source=web&ots=VpCgGdCVbC&sig=Nc4SaE1AFejpwiDidKjj1WAV0qE#PPA125,M1