Biorenewable materials from isosorbide

As petroleum feedstocks start to dwindle, it is becoming more important to find acceptable replacements for materials made from these feedstocks. Polyurethanes have classically been synthesized from petroleum-based feedstocks, and depending on its properties, polyurethanes can be used in everything from foams, to construction plastics. In recent years there has been an increasing amount of research trying to replace petroleum-based chemicals those derived from biobased sources. One such compound, isosorbide, is a rigid diol that has seen an increasing amount of research as a replacement for hard segments of polymers. While there has been much work incorporating isosorbide into polyurethanes as a diol, there has been relatively little work incorporating isosorbide as a diisocyanate. Previously, isosorbide has been directly functionalized via and SN2 and oxidation-reduction method. Our approach introduced a tether, succinic anhydride, which is increasingly produced through fermentation. Reaction of isosorbide with succinic anhydride results in a dicarboxylic acid that can be subsequently converted to a diacid chloride. The diacid chloride then undergoes a two-step Curtius Rearrangement to afford an isosorbide-based diisocyanate. Subsequent proof of concept polyurethanes were synthesized and characterized to analyze the properties of our newly synthesized diisocyanate. Tackifiers are a relatively unknown class of molecules that are used extensively in the adhesives industry. Usually derivatives of resin acids (diterpenes), terpenes, or petroleum-based starting materials, tackifiers, are used to improve wetting, tack and adjust the glass transition temperature of an adhesive. While most small molecules are crystalline and have a very distinctive transition from a solid to a liquid, tackifiers are glassy amorphous small molecules that have a glass transition, like a polymer. Tackifiers are usually blend with block copolymers to form pressure sensitive adhesives, i.e. tape.