A method was validated intralaboratory to analyze low molecular weight P(D,L)LA (polylactic acid) in tetrahydrofuran (THF) with respect to the number average molar mass (Mn) and weight average molar mass (Mw). For this purpose, a KNAUER HPLC system was used in combination with a linear GPC column. The obtained molar masses were compared with the values of the absolute methods and any deviations were discussed. The method was validated with respect to its repeatability and robustness to changes in flow rate, temperature, injection volume and sample concentration.
14-point PS universal calibration in THF
Mn (dots) and Mw (squares) values at 0.3-, 0.5-, 1.0-, 2.0-, and 3.0 mg/ml sample concentration. Triple determination with relative standard deviation
|Substances||polylactide, polylactic acid|
|Key words||PLA, polylactide, polylactic acid, GPC, SEC, polymer, biopolymers, bioplastic, biodegradable, universal calibration, PS, polystyrene, PMMA, green SEC, green GPC, biobased plastic, validation|
|Version||Version 1/ 11/2021|
Determining molecular weights of polylactic acids
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