Starch-derived polyols for polymer technologies: preparation by hydrogenolysis on metal catalysts

Aqueous solutions of sorbitol derived from biosustainable resources are converted by catalytic hydrogenolysis to a mixture of C-4-C-6 polyols for the synthesis of alkyds dagger employed in paint manufacture. Copper catalysts were selected because of their larger activity in the dehydroxylation reaction than in C-C bond breakage. Reactions at 180 degrees C under H-2-pressure in the presence of CuO-ZnO catalyst gave a 73% yield of C4+ polyols, and more specifically, 63% of deoxyhexitols. The mixture of polyols was effectively employed as a substitute for hydrocarbon-derived polyols in the synthesis of alkyd polymers.