Submitted to: Journal of Biobased Materials and Bioenergy
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/5/2013
Publication Date: 6/24/2013
Citation: Wyatt, V.T., Yadav, M.P., Latona, N.P., Liu, C. 2013. Thermal and mechanical properties of glycerol-based polymer films infused with plant cell wall polysaccharides. Journal of Biobased Materials and Bioenergy. 7:348-356. Interpretive Summary: Developing new outlets for glycerol would have a significant impact on the economics of biodiesel production if value-added products can be made from glycerol. Glycerol is the major by-product generated from biodiesel production. Before the introduction of biodiesel-derived glycerol, the glycerol market was already saturated. Therefore, increased production of glycerol from biodiesel made the situation worse and created a need to find uses for newly generated amounts of glycerol. In this study, we have shown that bioplastics made from glycerol can be physically strong and heat stable. These properties make them viable candidates for applications in the food and drug industries.
Technical Abstract: Poly(glutaric acid-co-glycerol) films were produced by first synthesizing polymer gels from uncatalyzed polyesterification of glutaric acid to glycerol in toluene. Residual amounts of starting materials in the gel matrices were determined by gas chromatography (GC) to contain 15 percent glycerol and 0.6 percent glutaric acid or 0.2 percent glycerol and 16.4 percent glutaric acid, respectively for the 2:1 and 1:2 (glutaric acid:glycerol) molar ratio formulations. The 2:1 (glutaric acid:glycerol) formulation was cured at 135 deg C for 12 h to form polymer films with and without the incorporation of lignocellulosic biomass or purified plant cell wall polysaccharides (sugarcane bagasse, corn fiber gum, pectin, or microcrystalline cellulose. The 1:2 (glutaric acid:glycerol) gel formulation was cured at 135 deg C for 24 h. FTIR results suggest that the films were completely cured. Heat capacity ('delta'Cp) and glass transition temperature (Tg) for all specimens averaged 0.41(+/-0.1) J/g* deg C and -14.82 (+/-2.01) deg C, respectively. The thermal curves of the polymers showed total degradation for all polymer films at approximately 400 deg C. The addition of microcrystalline cellulose into the polymer matrix showed a 3-fold increase in tensile strength and Young’s modulus and a two-fold increase in fracture energy when compared to the control.