The crystallinity of a compound can be calculated using differential scanning calorimetry (DSC) data by comparing the melting enthalpy of the sample to that of a fully crystalline reference material. Here are the steps:
Obtain the DSC thermogram of the sample and note the melting peak temperature and the melting enthalpy (ΔH) of the sample.
Choose a fully crystalline reference material that has a well-defined melting peak at a similar temperature range as the sample. The melting enthalpy of the reference material should be known.
Normalize the melting enthalpy of the sample (ΔH_sample) by dividing it by the theoretical melting enthalpy of the reference material (ΔH_ref) calculated by multiplying its enthalpy of fusion (ΔH_fus) by its degree of crystallinity (X_c):ΔH_sample/ΔH_ref = ΔH_sample/(ΔH_fus X_c)Here, ΔH_fus is the enthalpy of fusion of the reference material, which can be obtained from literature or experiment.
Solve for the degree of crystallinity (X_c):X_c = ΔH_sample/(ΔH_fus ΔH_ref)The degree of crystallinity (X_c) represents the fraction of the sample that is crystalline, expressed as a percentage.
It is important to note that the accuracy of the crystallinity calculation depends on the choice of reference material and the assumptions made regarding its degree of crystallinity and enthalpy of fusion. Additionally, DSC is a bulk analytical technique and may not accurately represent the crystallinity of specific regions or phases within a sample.
You can calculate percentage of crystallinity from Differential Scanning Calorimetry (DSC) study. By dividing the amount of the crystalline phase by the total amount of the material and multiplying by 100
Normalize the melting enthalpy of the sample (ΔH_sample) by dividing it by the theoretical melting enthalpy of the reference material (ΔH_ref) calculated by multiplying its enthalpy of fusion (ΔH_fus) by its degree of crystallinity (X_c):ΔH_sample/ΔH_ref = ΔH_sample/(ΔH_fus X_c)Here, ΔH_fus is the enthalpy of fusion of the reference material, which can be obtained from literature or experiment.