Development of a semi-quantitative attenuated total reflection infrared spectroscopy analysis method for the study of compatibility of hindered amine stabilizers in polyethylene films

摘要

Attenuated total reflection (ATR) infrared analysis has been applied to low density polyethylene films containing a certain amount of high molecular weight hindered amine stabilizers (HAS), in order to estimate the surface concentration increase with time at different temperatures. A semi-quantitative method that gives a nominal concentration value has been developed, by making use of mathematically corrected ATR spectra that can be compared with transmittance spectra of samples containing known amounts of the additives. The limitations of such methods are critically discussed. Even though spectra manipulations limit the accuracy and the significance of a "surface concentration" is not fully rigorous, the output values can be useful to make comparisons between different additives; those examined are both very compatible in the polymer matrix and only the permanence at 60 degreesC for >1 year results in a certain increase of the concentration near the surface, due to migration. (C) 2001 Elsevier Science Ltd. All rights reserved. [References: 10]