A novel approach for qualitative determination of residual tin based catalyst in poly(lactic acid) by X-ray photoelectron spetroscopy

Abstract

This work is focused on description of qualitative determination of residual tin based catalysts in poly(lactic acid) by using X-ray photoelectron spectroscopy and fluorimetry as standard technique. Three types of poly(lactic acid) were prepared by direct melt polycondensation of lactic acid by using methanesulfonic acid (w = 0.5 %) or various amount of stannous 2-ethylhexanoate (w = (0.5 and 2) %). The results from both methods show that the amount of observed tin in the samples correlates with the concentration of the stannous 2-ethylhexanoate used for polycondensation. X-ray photoelectron spectroscopy was proven to be suitable for detection of tin residuals in polymer matrix.