Characterization and Performance Assays

Calibration of the MALS detector was performed with a polystyrene standard with Mw = 17 500, Mw/Mn = 1.02 and dn/dc = 0.185. The RI peak and light scattering (LS) detector peak for polystyrene standard were aligned within the ASTRA software. A sample of commercial PCL purchased from Sigma-Aldrich with Mw 14 000 was diluted in TH F and injected to GPC for confirmation of molecular weight value by MALS detector. It was confirmed that GPC-MALS is capable of accurate determination of absolute molecular weight, even for lower molecular weight polymers of about 14000. 

A series of polystyrene standards were purchased from Waters Corporation and American Polymer Standards Corporation for creating a calibration curve and determination of molecular weight by elution time based on polystyrene standards number. The calibration curve was created using Chemstation GPC module software. The molecular weight determined by this method was used for comparison with literature data, since polystyrene standards are commonly used for reference. 

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