i prepared a semicrystalline polymer consisting of one crystalline and one amorphous monomer.I carried out DSC and now considering to calculate its degree of crystallinity using the following equation.
Degree of crystallinity = ((Delta Hf - Delta Hc)/Delta Hf,100%) x 100%
where Delta Hf is the enthalpy of melting, Delta Hc is the enthalpy of crystallization, and Delta Hf,100% is the enthalpy of melting for a fully crystalline polymer.
Here my question is which value to use for Delta Hf,100%? Should I carryout the DSC of the polymer consisting only the crystalline monomer and use its melting enthalpy or should I use any reported value for 100% crystalline polymer? kindly help.
Thanks in advance.
you should seek the information from the literature. i.e. use the value from literature.
however, if you want to determine this value experimentally you should see the following article.
Article The crystallinity of poly(ether ether ketone)
Thank you for your answer Dr. Abdul Al Lafi ,Can you tell me, how to choose the polymer? for example some polymer have Delta Hf,100% near 200 or 300 j/g while few have near 88 or 100. the result will affect a lot by these values. Thank in advance
Dear Kumkum Ahmed , you may see the attached paper regarding this issue. Here you will find two terms to calculate degree of crystallinity (ΔHm, the enthalpy of melting calculated from DSC and ΔHm° is the enthalpy of melting for 100% crystalline polymer, e.g., for PVA, ΔHm° is 138.6 J g-1).
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