Check the following researches, they might be of help:
DOI: 10.1039/TF9444000251
DOI: 10.1021/ma60048a040
DOI: 10.1021/ja01611a10
DOI: 10.1007/s101890070030
Melting of crystalline materials is a first order phase transition, according to Ehrenfest classification. Also following that classification, the glass transition can be interpreted as resembling a second order phase transition ─ under idealized circumstances not realized in practice. For further discussion, see:
Article Aspects of the non-crystalline state
the peak position (285.2 EV) in the xps spectra for carbon is corresponding to which type of carbon (SP,SP2 or SP3).
thank you
Dear Aisha Alasfar,
Flowing and melting only regards thermoplastics, which can be purely amorphous, but are in most cases semi-cristalline. In practice, Young's modulus or the E-modulus as a function of temperature is very suitable to illustrate the (mechanical) behaviour. If a polymer would be 100% crystalline, a sharp decrease of the E-modulus proceeds at Tm, the melting temperature of the polymer crystals. However, this behaviour will never be found in practice, since the structure in the crystalline regions will not always be perfect. The result of imperfection is a statistical distribution of melting points, the upper limit being the melting point of a perfect polymer crystal and the lower limit being that of the most imperfect crystal. The distribution of melting temperatures causes the E-modulus to decrease gradually in the region between the glass transition and the melting point.
A further discussion of melting of semi-cristalline thermoplastics can be found in Section 3.5.4 of the Reference, where the following issues are treated as well: necessary condition for crystallization (regular chain structure), the flexibility of the polymer chain and the influence of chain interactions.
Reference
Materials Science in Design and Engineering, Delft NL, 2012
http://www.delftacademicpress.nl/m017.php
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