Production of bio-degradable polyurethane foam from sugarcane bagasse and biodiesel-derived crude glycerine

Abstract

As the threat of the depletion of fossil based fuels becomes more of a reality, there is a need to find alternative carbon sources for the production of a wide range of chemicals, polymers and plastics. One plastic that is used in almost every aspect of everyday life is polyurethane foam. Currently it is produced through polyols and diisocyanates that are all obtained from fossil based resources such as crude oil and coal. Lignin is a by-product from the second generation bioethanol process and crude glycerol is a by-product of biodiesel production through transesterification. These two by-products can be combined to produce polyurethane foam of high quality. In this study, the influence of reaction parameters such as temperature, pH of the crude glycerol, and reaction time on the hydroxyl numbers and the properties of the produced foam was investigated. Foam properties such as density, cell size and compression strength was studied. Results showed that the hydroxyl numbers and thus the properties of the lignin and crude glycerin used as reagents have a significant influence on the foam density and rigidity. The foams were tested for biodegradability using a standard ASTM method and it was shown that the produced foams degraded faster than commercial rigid polyurethane foam. Polyurethane foams were also applied as ssDNA immobilization scaffolds by the DST/NWU Preclinical Drug Development Platform, on campus, to determine the potential to be used as part of a diagnostic system. Results showed that polyurethane foam is a viable starting material for immobilization scaffolds in the development of an affordable and practical point-of-care tuberculosis diagnostic system