In a closed MASc oral exam Yasaman Yasoubi will present their research on : Nanocellulose in Bioplastics for Sustainable Packaging.
Abstract:
The current packaging materials market is dominated by petrochemical-derived, single-use, and inexpensive plastics that are incredibly stable in the environment. After their sole use, only a small fraction is recycled, with the remaining ending up in landfills, incineration facilities, or littered in the environment threatening the health of our environment.
To solve environmental problems related to using petroleum-based packaging materials, Bio-based materials have attracted widespread attention for packaging applications since they are biodegradable, renewable, and have a low carbon footprint. They provide a great opportunity to reduce the extensive use of fossil fuels and develop packaging materials with good properties, addressing environmental problems and contributing significantly to sustainable development.
However, weak mechanical properties, high gas/water permeability and poor stability during processing of bioplastics in comparison with non-biodegradable materials have limited their application.
There are different methods to enhance these properties among which the addition of nanomaterials, especially cellulose nanofibers, is the most effective method.
These days, thermoplastic starch (TPS) has attracted much attention among bioplastics. Cassava Starch is cheap, non-toxic, abundant, and biodegradable but it is hard to process and shows low barrier and mechanical properties. To overcome the processing problem, we can add plasticizer like Glycerol to the blend that causes a reduction in water resistance. In addition, blends of Polybutylene succinate (PBS) and TPS (30%) were prepared as a means of producing low-cost composite materials with good performance. The TPS and PBS blends were prepared by extrusion and Hot press and their morphological, mechanical, barrier properties were evaluated. The results showed the presence of fiber in the composite acted as reinforcement in the matrix and improved the mechanical properties and to some extent barrier properties, especially after adding Citric Acid as a compatibilizer.
The main goal of this project is making biodegradable nanocomposite films for packaging application with good barrier properties. PBS has good transparency and mechanical properties as well as good resistance to Water but high cost and poor resistance against oxygen. So, in this study PBS blended with CNF to increase biobased content, increase biodegradation rate, and reduce the price. But the CNF produced in our lab from the Hemp after bleaching and refining. Nanocomposites composed of CNF and PBS were prepared using an Extruder and hot press. Microstructure, barrier, and mechanical properties of the nanocomposites were studied. Scanning electron microscopy (SEM) micrographs revealed better distribution of nanoparticles in the polymer matrix for lower contents (less than 15 %), but also that a higher content
(30 and wt%) of CNF was easily agglomerated. This caused the nanocomposites act as a brittle material The results of water vapor permeability (WVP) tests showed that the use of nanofibers had no significant effect on the permeability of films. But the oxygen permeability improves a lot.
Overall, the PBS/CNF nanocomposites in this research offered good properties for sustainable packaging depends on the final application of products. But still some works needed to improve and enhance the final properties.