The Use of Glycerol Carbonate in the Preparation of Highly Branched Siloxy Polymers

Abstract

Glycerol is an important biomass feedstock readily available as a by-product from the production of fatty acid methyl esters (FAME). Glycerol can be converted to glycerol carbonate, which readily reacts with many nucleophilic reagents including amines. Here, we demonstrate the reaction of glycerol carbonate and 3-aminopropylalkoxylsilane to yield hydroxyl alkyl terminated silanes. This reaction follows a second order rate constant irrespective of the type of aminosilane that was used. These hydroxyl alkyl terminated silanes were further polymerized to yield highly branched siloxy polymers via self-polycondensation through exchange of the ethoxy groups attached to the silicon atom with the terminal hydroxyl groups. The biobased content of these products was determined by ASTM 6866 to be as high as 69 %. The synthesis of the silane monomers as well as the structure and key properties of the hydroxyl alkyl terminated siloxy polymers were determined by DSC, 1H NMR, FTIR, TGA and GPC.