Fabrication and characterization of bio-based and biodegradable cellulosic composites in polyhydroxyalkanoate matrix

Environmental concerns are increasingly important in modern society, and the development of innovative and sustainable materials, which can substitute the oil-based polymers, is one of the main achievement for science and industry. This PhD thesis deals with the fabrication of bio-based and biodegradable composites, obtained melt compounding a poly(3- hydroxybutyrate-co-3-hydroxyhexanoate) matrix with different cellulose agents. Here, a dual approach to the topic was investigated, first cellulose industrial by-product was used as inert filler to replace the biopolymer matrix and hence valorizing an agro-food waste. Secondly, chemically modified cellulose nanocrystals were used to obtain improved and tunable final properties of the composites. Furthermore, 3D-printability of these biocomposites was proved by developing structures of complex designs with a Fused Deposition Modeling 3D printer. The applicability of these innovative materials in biomedical field gave some promising results, and hence a deeper investigation was dedicated to biological characterization and use in tissue engineering. Findings from this research study can serve as an important step forward toward the development of ecofriendly materials for 3D-printing complex architectures with tailored mechanical properties and functionalities.