Molecular Weight Distribution of Low Molecular Weight Polyols Derived from Fatty Acid Methyl Esters

A series of commercial polyether polyols with well-defined molecular weights (MW) was used along with propylene glycol and dipropylene glycol as gel permeation chromatography (GPC) calibration standards to determine the MW and oligomeric composition of the synthesized low MW fatty acid methyl ester (FAME) polyols, having an MW of lower than 600 Da. This GPC analysis was compared to the one calibrated against the commercially-available polystyrene (PS) standards and to the number-average molecular weight (M (n)) obtained via vapor pressure osmometry (VPO) technique. The MW of FAME polyols obtained with GPC calibrated against polyether polyols were closer to the M (n) values obtained via VPO than the MW obtained via GPC calibrated against PS standards. Using the reliable GPC calibration, the MW distribution and the hydroxyl functionality of FAME polyols were determined with greater confidence.