Dottore di ricerca

ciclo: XXXV

supervisore: Francesca Leonelli

Titolo della tesi: Renewable feedstocks, applications, and new exchange reactions: a prospective in the field of Covalent Adaptable Networks

Covalent Adaptable Networks (CANs) are a new class of dynamic polymeric materials. CANs possess a cross-linked structure formed by reversible covalent bonds that makes them recyclable and reprocessable (thanks to the dynamicity of the cross-links) with the application of the appropriated stimulus, but at the same time lend them excellent mechanical properties (thanks to the 3D cross-linked network). In this way, CANs possess the finest characteristic of both thermoplastics and thermosets. This PhD thesis is focused on the preparation of innovative Covalent Adaptable Networks, both employing monomers obtainable from renewable feedstock and both applying new, and never reported, covalent dynamic chemistries. An introduction, containing an analysis and some considerations on the actual situation of the polymeric material field, is reported in Chapter 1. In the second chapter is reported the first application of the catalyzed transamidation reaction in the preparation of a CAN. A renewable feedstock (oleic acid) has been employed as the starting material for the polymer preparation. The insertion of a catalyst (boric acid) allow the exploitation of the transamination reaction, thus generating a dynamic polymeric material with excellent mechanical and thermal properties, that can be tuned by varying the B(OH)3 content. In the third chapter it has been tried to merge the preparation of new CANs with the investigation on their possible applications. A series of dynamic polymers, prepared starting from oleic acid and containing aromatic disulfide moieties, have been prepared and characterized. Moreover, their application as polymeric reusable adhesive for metals (copper and aluminum) has been investigated. The tested materials revealed great adhesive properties towards copper and, being fully recyclable, the joint created with these materials could be easily reprocessed with just a slight decrease of the shear strength, thus confirming their possible application as innovative, bio-based, reusable metal adhesive. In the last chapter a new exchange reaction, that is oxime metathesis, has been reported. The latter, in contrast to imine chemistry, exhibits high hydrolysis resistance. The proposed mechanism is well supported by both experimental and computational studies, and it has been demonstrated the possibility to tune the metathesis reaction rate by changing the substituents attached to the aromatic ring bringing the oxime function. Finally, to demonstrate how this new reaction can be employed as a new dynamic chemistry, a cross-linked dynamic polymeric material, that exploits it to gain the ability to be recycled and reprocessed while maintaining its mechanical properties, has been prepared and characterized.

Produzione scientifica

11573/1698957 - 2023 - Oxime Metathesis: Tuneable and Versatile Chemistry for Dynamic Networks
Sardon, Haritz; Pettazzoni, Luca; Ximenis, Marta; Leonelli, Francesca; Vozzolo, Giulia; Bodo, Enrico; Elizalde, Fermin - 01a Articolo in rivista
rivista: CHEMICAL SCIENCE (Cambridge : Royal Society of Chemistry, 2010-) pp. - - issn: 2041-6520 - wos: (0) - scopus: 2-s2.0-85182382195 (0)

11573/1659670 - 2022 - Self-Healing and reprocessable oleic acid-based elastomer with dynamic S-S bonds as solvent-free reusable adhesive on copper surface
Pettazzoni, Luca; Leonelli, Francesca; Marrani, Andrea; Migneco, Luisa; Vetica, Fabrizio; Celio, Lorenzo; Napoleone, Valerio; Alfano, Sara; Colecchia, Andrea; Amato, Francesco; Di Lisio, Valerio; Martinelli, Andrea - 01a Articolo in rivista
rivista: POLYMERS (Basel : Molecular Diversity Preservation International) pp. - - issn: 2073-4360 - wos: WOS:000887814700001 (0) - scopus: 2-s2.0-85142439389 (0)

11573/1624598 - 2022 - Transamidation-based vitrimers from renewable sources
Pettazzoni, Luca; Leonelli, Francesca; Martinelli, Andrea; Migneco, Luisa Maria; Alfano, Sara; Di Luca, Daniele; Celio, Lorenzo; Di Lisio, Valerio - 01a Articolo in rivista
rivista: JOURNAL OF APPLIED POLYMER SCIENCE (New York, NY : John Wiley & Sons) pp. - - issn: 1097-4628 - wos: WOS:000772884300001 (5) - scopus: 2-s2.0-85127259201 (5)

11573/1610507 - 2022 - Organocatalyst design for the stereoselective annulation towards bicyclic diketones and analogues
Vetica, Fabrizio; Pandolfi, Fabiana; Pettazzoni, Luca; Leonelli, Francesca; Bortolami, Martina - 01g Articolo di rassegna (Review)
rivista: SYMMETRY (Basel : Molecular Diversity Preservation International) pp. 355- - issn: 2073-8994 - wos: WOS:000764147400001 (6) - scopus: 2-s2.0-85124661300 (5)

¬© Università degli Studi di Roma "La Sapienza" - Piazzale Aldo Moro 5, 00185 Roma