Overview of advances in sugar-based polymers

Polymeric biomaterials, especially agricultural commodity-based polymers, have been moving forward quickly during the last few years because of the significant rise in oil and natural gas prices. From a life-cycle perspective, sugar is a renewable resource that has the potential to be used as an alternative to petroleum-based polymers. The objective of this work is to demonstrate the wide utility of a cereal-derived material, isosorbide, for high added value applications in polymers. As a bicyclic ether derivative of glucose, isosorbide is classified by the Food and Drug Administration as a "generally recognized as safe" (GRAS) material. Because of its rigidity, chirality, and nontoxicity, isosorbide can be incorporated into thermosets and thermoplastics. Such processes and products offer a more sustainable and "green" technology. By making the diglycidyl ether, isosorbide epoxy resins were synthesized in this work as a new class of thermosets with comparable dry mechanical property similar to bisphenol A (BPA) epoxide. These could be a potential replacement for BPA in coatings and adhesives. By controlling the stereochemistry, multiple isosorbide-derived AB monomers such as isosorbide methyl terephthalate were synthesized for future homopolymerization and copolymerizations with commercial available polymers like polyethylene terephthalate (PET) and PLLA. The increased glass transition temperature and semicrystalline morphology of these isosorbide copolyesters demonstrate a way to improve the performance of polyester thermoplastics in many applications such as hot-fill containers and engineering resins. All the intermediates generated during the syntheses were characterized by NMR. The thermal tests were conducted using the techniques of DSC and thermogravimetric analysis (TGA).