Andrea Dorigato

In this thesis work, various types of bio-based polymers (preferably biodegradable) will be considered as matrices for the development of innovative and eco-friendly polymer composites based on nanochitin, for applications in the packaging sector. Following the optimization of materials, production processes, and formulations, an extensive morphological and thermo-mechanical characterization will be then conducted.

Piezoelectric materials, by converting mechanical stress or deformation into electrical energy, are promising candidates for the development of new actuators, energy storage devices, and medical devices. The proposed thesis project will focus on the development of eco-friendly and multifunctional polymer nanocomposites with high piezoelectric properties, to be used in the field of energy harvesting (actuators and devices for energy conversion and storage). Following the optimization of the synthesis process of ceramic nanofillers, a thorough structural and microstructural characterization will be conducted. The nanofillers will then be introduced into various bio-based and/or biodegradable polymer matrices with properties suitable for the intended application, adding compatibilizing agents to promote the dispersion of the nanofillers. Samples for analysis will be produced using low environmental impact net-shape technologies (e.g., additive manufacturing). Extensive electrical and piezoelectric characterization will follow the determination of the microstructural and thermo-mechanical properties of the prepared nanocomposites, to assess their suitability in energy harvesting applications.

Currently, summer conditioning accounts for over 25% of total electricity consumption worldwide, and this figure is expected to further increase in the next decade. The barocaloric effect (BCE) belongs to emerging solid-state refrigeration technologies. The solid-state nature of refrigerants in these technologies prevents the accidental release of refrigerants into the atmosphere, unlike traditional vapor compression systems. Therefore, the objective of this thesis project is to develop new polymeric composites for barocaloric applications, featuring high versatility, fatigue resistance, high efficiency, and rapid heat transfer during the thermo-mechanical cycles.

In this thesis project, the possibility of developing synthetic polymer foams (e.g., polyurethane, phenolic resin) with high thermal insulation and reduced environmental impact will be considered. Recycled insulation material will be used to reduce the environmental impact of these insulation products. The materials will be mixed during production, and optimal formulations and process conditions will be defined. The resulting samples will be fully characterized from a morphological and thermo-mechanical perspective.

Within this thesis project, an innovative soil cover (top soil cover) will be developed based on a biodegradable bio-composite with water regulation properties. This multifunctional material is intended to control rainwater absorption and soil evaporation rate, aiming to reduce erosion and nutrient leaching. This cover will enable new seeding methods to expand forests and contribute to planting young trees in unfavorable sites (e.g., arid regions). The produced top soil cover will then be characterized from a physical, mechanical, and chemical standpoint. Additionally, a life cycle assessment (LCA) will be conducted to evaluate the environmental impact of the introduced innovation.

It has been demonstrated that the introduction of conductive nanofillers into fiber-reinforced polymers allows for electrical monitoring of structural health and stress in the produced materials. Additionally, the use of polymer matrices with relatively low melting temperatures in combination with polymer matrices for structural composites can enable damage repair within the material through thermal effects. The idea of the present work is to develop composite systems capable of electrically monitoring damage and self-repairing through Joule heating by introducing electrically conductive nanofillers. Various polymer matrices (both biodegradable and non-biodegradable) and different carbonaceous nanofillers will be considered.

The activity will be carried out within the European project NORUBTREET_4_LIFE. The thesis work aims to address the challenge posed by the EU regulation prohibiting the use of used tires as secondary raw materials in the production of playgrounds for children and sports fields, due to the release of polycyclic aromatic hydrocarbons (PAHs), substances proven to be hazardous to human health and the environment. An effective solution to this problem involves designing a closed-loop recycling process for used tires, i.e., producing tires from tires. This would mitigate the impact of the aforementioned restrictions introduced by the new EU regulations on the management of end-of-life tires. In these new rubber blends, a zero content of PAHs will be achieved. This will create conditions for the elimination ab initio of the impact of PAHs, not only in the tire recycling phase but also during the primary life, with obvious positive consequences for health and the environment. Furthermore, the feasibility of eliminating PAHs from rubber materials obtained from used tires will be explored by designing a suitable recycling process, during which PAH-containing substances will be removed, while providing rubber materials fully compliant with the required performance specifications and existing legislation. These PAH-free materials will be tested and validated, both regarding their functional properties and emission behavior.

Furan based polyesters represent an innovative and sustainable alternative to traditional petroleum-based polymers. In this thesis project, various types of furanoates will be used for the production of non-woven textiles via an electrospinning process, to be employed in two crucial sectors for the development of modern society: the production of transdermal drug release patches for biomedical applications and the fabrication of porous separator membranes for lithium batteries. The materials will be processed through electrospinning, optimizing process conditions based on the intended application. The developed networks will then undergo thorough microstructural, chemical, and thermo-mechanical characterization, and the most promising formulations will subsequently undergo an extensive technological validation campaign to determine the technical and economic potential of the introduced innovation.

The work will be carried out partly at the SETA Polymers Srl plant (Fontanive, PD) and partly at the Department of Industrial Engineering of UNITN. The thesis activity will involve the preparation of new polymeric compounds, to be used in the footwear sector, by blending three different types of polymeric matrices (TPU, EVA, and PE), using recycled materials. The materials will be processed according to expanded material processing technologies. The first part of the work will involve identifying the most promising formulations for the expanded blends, which will then be characterized from a morphological and thermo-mechanical perspective.