Periodic Reporting for period 1 - SURE-Poly (Sustainable and Recyclable Polymeric Thermosets)
Reporting period: 2023-03-01 to 2025-02-28
The SURE-Poly project focuses on developing sustainable thermoset materials through an integrated approach. This involves utilizing renewable precursors derived from agro-alimentary and biomass waste, while simultaneously incorporating dynamic covalent bonds into polymeric networks to impart recyclable properties to the thermosets. The concerns connected to petroleum-based origin of polymeric materials and the problems related to the accumulation of plastic waste in the environment need an urgent solution. One possible strategy to address this dramatic situation is the exploitation of bio-based resources as precursors for polymers. The human activity produces 998 milion tonnes of agricultural waste and similar amount of food-waste are produced. The valorization of these wastes could be of paramount importance, but complex at the same time. In fact, finding a way to convert waste into added value products is the actual concern of most of the researchers in order to become greener and more sustainable.
The use of biobased polymers, monomers and oligomers can represent a green alternative since they are based on renewable resources and possess low CO2 emissions.
One promising strategy to achieve sustainable and recyclable thermosets is the implementation of dynamicity in crosslinked polymeric materials. This can be imparted into the polymeric networks by the presence of labile noncovalent and dynamic bonds capable of undergoing reversible formation and cleavage giving to the corresponding materials innovative recyclability properties.
Within this frame, this project aims to face the complex challenge of the production of sustainable and recyclable polymeric thermosets. The proposed target can be reached by exploiting the peculiar properties of dynamic covalent polymeric networks, which allows a direct recyclability or reprocessability of thermosets, together with the use of bio-based polymeric precursors. Therefore, the integration of dynamic covalent properties with bio-based materials appears a great combination of choice to achieve the expected aim, which goes beyond the state of the art, by put together sustainability and recyclability of advanced polymeric composites.
The use of biobased polymers, monomers and oligomers can represent a green alternative since they are based on renewable resources and possess low CO2 emissions.
One promising strategy to achieve sustainable and recyclable thermosets is the implementation of dynamicity in crosslinked polymeric materials. This can be imparted into the polymeric networks by the presence of labile noncovalent and dynamic bonds capable of undergoing reversible formation and cleavage giving to the corresponding materials innovative recyclability properties.
Within this frame, this project aims to face the complex challenge of the production of sustainable and recyclable polymeric thermosets. The proposed target can be reached by exploiting the peculiar properties of dynamic covalent polymeric networks, which allows a direct recyclability or reprocessability of thermosets, together with the use of bio-based polymeric precursors. Therefore, the integration of dynamic covalent properties with bio-based materials appears a great combination of choice to achieve the expected aim, which goes beyond the state of the art, by put together sustainability and recyclability of advanced polymeric composites.
The SURE-Poly project aims to develop sustainable thermoset materials through an integrated approach. Renewable precursors derived from agro-alimentary and biomass waste were utilized and functionalized using green chemistry. These precursors were then processed to form crosslinked polymeric networks. By introducing dynamic covalent bonds into these networks, recyclability and reduced waste generation was therefore achieved throughout the thermoset lifecycle. Overall, the activities have been performed according to the following steps:
Waste Recovery and Valorization
The project began with recovering and valorizing waste from agro-food industries. Plant and woody biomass serve as an attractive and abundant source of bio-based precursors for thermoset synthesis. Plant biomass, as the Earth's most abundant renewable feedstock, provides significant opportunities. For instance, the pulp and paper manufacturing industry is identified as a promising sector for bio-based plastics, leveraging its wood-based lignocellulose availability. Lignin, the second most abundant biopolymer globally and an industrial by-product of the pulp and paper industry, is produced at approximately 50 million tons annually. However, less than 2% of lignin is currently used for producing chemicals or lignin-based products, with the rest predominantly utilized for energy generation. Recognizing lignin’s potential, it was selected as a feedstock for this project. Various bio-derived building blocks were developed (WP1) and subsequently functionalized (WP2).
Functionalization of Bio-Based Polymers
In WP2, recovered bio-based polymers were functionalized through methacrylation, acrylation, allylation, and oxidation reactions to introduce epoxy functional groups. These functionalized monomers were then employed to produce bio-based polymer networks using environmentally friendly UV-curing processes, which emit low levels of volatile organic compounds (VOCs) and consume minimal energy. Traditional thermal curing methods were also applied (WP3). The resulting polymer networks were designed to exhibit dynamic covalent bonds properties, enabling network rearrangement under thermal stimuli. Stress-relaxation measurements confirmed these properties, as applied forces led to significant stress relaxation, absent in permanently crosslinked networks.
Application in 3D Printing
In the final phase (WP4), the previous investigated bio-based formulations were employed in 3D printing technologies. This approach enabled the creation of complex 3D structures with dynamic topology properties. These structures demonstrated reprocessability and recyclability, advancing the potential for sustainable applications of bio-based polymers.
Through its innovative integration of waste valorization, green chemistry, and advanced processing techniques, the SURE-Poly project underscores the viability of sustainable thermoset materials for a circular economy.
Waste Recovery and Valorization
The project began with recovering and valorizing waste from agro-food industries. Plant and woody biomass serve as an attractive and abundant source of bio-based precursors for thermoset synthesis. Plant biomass, as the Earth's most abundant renewable feedstock, provides significant opportunities. For instance, the pulp and paper manufacturing industry is identified as a promising sector for bio-based plastics, leveraging its wood-based lignocellulose availability. Lignin, the second most abundant biopolymer globally and an industrial by-product of the pulp and paper industry, is produced at approximately 50 million tons annually. However, less than 2% of lignin is currently used for producing chemicals or lignin-based products, with the rest predominantly utilized for energy generation. Recognizing lignin’s potential, it was selected as a feedstock for this project. Various bio-derived building blocks were developed (WP1) and subsequently functionalized (WP2).
Functionalization of Bio-Based Polymers
In WP2, recovered bio-based polymers were functionalized through methacrylation, acrylation, allylation, and oxidation reactions to introduce epoxy functional groups. These functionalized monomers were then employed to produce bio-based polymer networks using environmentally friendly UV-curing processes, which emit low levels of volatile organic compounds (VOCs) and consume minimal energy. Traditional thermal curing methods were also applied (WP3). The resulting polymer networks were designed to exhibit dynamic covalent bonds properties, enabling network rearrangement under thermal stimuli. Stress-relaxation measurements confirmed these properties, as applied forces led to significant stress relaxation, absent in permanently crosslinked networks.
Application in 3D Printing
In the final phase (WP4), the previous investigated bio-based formulations were employed in 3D printing technologies. This approach enabled the creation of complex 3D structures with dynamic topology properties. These structures demonstrated reprocessability and recyclability, advancing the potential for sustainable applications of bio-based polymers.
Through its innovative integration of waste valorization, green chemistry, and advanced processing techniques, the SURE-Poly project underscores the viability of sustainable thermoset materials for a circular economy.
The use of biobased polymers, monomers and oligomers can represent a green alternative to fossil based polymers, since they are based on renewable resources and characterized by low CO2 emissions during production. However, it is important to stress that the term biobased does not include biodegradability in its definition, therefore not every biobased polymer is biodegradable and recyclable.
Besides, the current bio-based polymer market is dominated by thermoplastics, while the market of thermosetting polymers is still even more limited. Traditional thermosets are network polymers that cannot be thermally reprocessed; hence recycling is difficult if not impossible. Taking into consideration the large diffusion of polymeric thermosets in sectors such as automotive, boat industry, composites and constructions, the development of bio-based reprocessable and/or recyclable thermosets still represents a great challenge for both industry and academics.
The important advancement of our project is the design of biobased precursors, derivatized by agro-food industrial waste, which were exploited in UV and thermal curing of thermosets characterized by dynamic covalent network. We have demonstrated the feasibility of achieving biobased thermosets which could be recycled and reshaped by simple thermal treatment, as a classical thermoplastic material.
We have completed a circular economy attitude achieving new sustainable biobased recyclable thermosets materials starting from precursors extractable from bio-waste.
Besides, the current bio-based polymer market is dominated by thermoplastics, while the market of thermosetting polymers is still even more limited. Traditional thermosets are network polymers that cannot be thermally reprocessed; hence recycling is difficult if not impossible. Taking into consideration the large diffusion of polymeric thermosets in sectors such as automotive, boat industry, composites and constructions, the development of bio-based reprocessable and/or recyclable thermosets still represents a great challenge for both industry and academics.
The important advancement of our project is the design of biobased precursors, derivatized by agro-food industrial waste, which were exploited in UV and thermal curing of thermosets characterized by dynamic covalent network. We have demonstrated the feasibility of achieving biobased thermosets which could be recycled and reshaped by simple thermal treatment, as a classical thermoplastic material.
We have completed a circular economy attitude achieving new sustainable biobased recyclable thermosets materials starting from precursors extractable from bio-waste.