A Primary Method for the Determination of Hydroxyl Value of Polyols by Fourier Transform Mid-Infrared Spectroscopy

作者：Tavassoli Kafrani M H; Curtis J M^*; van de Voort F R

来源：Journal of the American Oil Chemists' Society, 2014, 91(6): 925-933.

DOI：10.1007/s11746-014-2451-0

• Alcohols
• Polyols
• p-Toluenesulfonyl isocyanate
• Carbamate
• AOCS method Cd 13-60
• Hydroxyl value

A primary Fourier transform infrared (FTIR) method was developed to determine the hydroxyl value (OHV) of polyols produced from edible oils. The method is a modification of American Society for Testing and Materials 1899-08, using toluene as the solvent to dissolve the sample and to carry the reactive reagent p-toluenesulfonyl isocyanate (TSI). TSI reacts with OH groups to produce a carbamate, a functional group that can be measured spectrally between similar to 1780 and 1690 cm(-1) in the differential spectrum that is obtained from spectra collected before and after the reaction. Commercially available 1-nonanol, which has a defined OHV, is used to develop a calibration. The OHV for a variety of 1A degrees and 2A degrees alcohols, as well as petrochemical and lipid-based polyols, were then measured to evaluate the performance of the method and to assess the effects of moisture on the results. The FTIR OHV were in accord with the results obtained by AOCS method Cd 13-60 and were demonstrated to be unaffected by the presence of moisture in the sample. The new TSI-FTIR method is simpler, much faster (similar to 10 min), and more reproducible and accurate than the AOCS OHV titrimetric methods and is not affected by carboxylic acids, amines or moisture.

• 出版日期2014-6
• 单位McGill