The effect of polymers and surfactants on the pour point of palm oil methyl esters

The objective of this research was to find some additives suitable to reduce the pour point (PP) of palm oil methyl esters. The PP properties of palm oil methyl esters (biodiesel) were evaluated with commercially available polymeric and surfactant compounds with various polarities, molecular sizes and structures. The compounds under study were poly(ethylene glycol), poly(methyl methacrylate), poly(ethylene-co-vinyl acetate), poly(styrene-co-maleic anhydride), poly(ethylene glycol) distearate, poly-(octadecyl methacrylate), poly(1-decene), poly(maleic anhydride-alt-1-octadecene), caprylic acid sodium salt, N-lauroylsarcosine sodium salt, polyoxyethylene(2) cetyl ether and polyoxyethylene(10) cetyl ether. Seven out of the twelve polymeric compounds tested were miscible in palm oil methyl esters due to similar polarities of the solute and biodiesel. The blends of the resultant seven polymeric compounds in palm oil methyl esters were evaluated respectively for their effect on the PP property. Poly-(maleic anhydride-alt-1-octadecene) was able to improve the PP of palm oil methyl esters from 12 to 6 °C when 2 wt-% was added. The cloud point was reduced from 12.9 to 8.1 °C, and the cold filter plugging point was reduced from 12 to 7 °C, whilst the flash point value remained unchanged at 156 °C when 2 wt-% of poly(maleic anhydride-alt-1-octadecene) was added to the palm oil methyl esters.