The increasing global materials consumption and the long-lasting detrimental effects of polluting manufacturing industries call urgently for innovative and sustainable new materials. Plastics, in particular, albeit ubiquitous and useful in an enormous range of applications, are associated with un-sustainable sourcing, manufacturing as well as end-of-life fates. During the past decades, various biodegradable plastics with properties comparable to those of commodity plastics have been pioneered. However, despite being biodegradable, these plastics were designed to degrade in aerobic environments, not in general landfills which is the place they usually end up in. As a result, even biodegradable plastics degrade at an unsustainably slow rate.<br/><br/>In this work we discuss the plasticization mechanism, as well as mechanical and thermal properties of bioplastics produced from selected plant and algal biomass. The biomass-based bioplastics are prepared by introducing various amounts (1-40 wt%) of low-carbon sugars as plasticizers and compounding the mixtures. We use a design of experiments to guide the formulations and processing conditions for each mixture. Specifically, we vary heating time, temperature, and shear stress in the extrusion process. The effects of varying the plasticizer amount and altering the processing parameters on the micro-morphology, mechanical and thermal properties of the produced bioplastics are characterized. We study the biomass particle morphology before compounding, through scanning electron microscopy (SEM). After the extrusion process, the bioplastic films are evaluated in terms of micro-morphology again through SEM, and their crystalline features are examined through X-ray diffraction (XRD). Tests are conducted to characterize the mechanical properties of the bioplastics (modulus, strength, elongation to break) and thermal stability is assessed through thermogravimetric analysis (TGA). The processing parameters as well as composition of the prepared bioplastics are correlated to the measured mechanical properties. Finally, a biodegradation assessment of the prepared bioplastics is conducted through characterizing their mass loss profiles during soil burial tests.

Effects of processing conditions and plasticizer concentration on the mechanical and thermal properties of bioplastics from plant and algal biomass

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.