Determining PCL Crystallinity by DSC

The produced filaments were analyzed by Differential Scanning Calorimetry (DSC; Q2000 TA instruments, Leatherhead, UK) to investigate the crystallinity of PCL. Tzero pans (TA instruments) were filled with approximately 5–10 mg of sample and placed in the DSC instrument after being non-hermetically sealed with Tzero lids using a Tzero Press (TA instruments). An empty Tzero pan was used as a reference. A heating run at a rate of 10 °C/min from 0 to 100 °C was performed. The DSC instrument was equipped with a refrigerated cooling system and dry nitrogen at a flow rate of 50 mL/min. The percentage of PCL crystallinity was calculated based on the following equation using the melt enthalpy obtained in the DSC experiments: $$Crystallinity=\frac{H_s}{H_{fc}\times R}\times 100\%$$

Hs is the melting enthalpy of a sample

R is the PCL content in a sample

Hfc is the melting enthalpy of 100% crystalline PCL which is 142 J/g [9 (link)]