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In this study, the physiological response of a sensitive lichen species (Evernia prunastri) exposed for three months in a complex urban area (Milan, Italy) was evaluated in order to verify if the air pollution abatement measures adopted over the years resulted in a suitable air quality for the survival of this sensitive species. Parameters investigated rely on the photosynthetic activity of the photobiont (Fv/Fm, PIabs, and OJIP curves), damage to mycobiont (membrane damage and antiradical activity), and the production of secondary metabolites involved in the protective functions of the organisms. Results showed that although air quality in Milan still suffers from heavy pollution from PM and NOx, the overall situation is not as severe as to induce the death of this sensitive biomonitor, at least in the short term. Nevertheless, the vital status of the samples exposed in the study area showed a significant impairment compared to that of samples exposed in a control area, indicating that the current air quality in Milan still prevents the optimal survival of E. prunastri.
Tania Contardo; Stefano Gazzotti; Marco Aldo Ortenzi; Andrea Vannini; Stefano Loppi. Biological Effects of Air Pollution on Sensitive Bioindicators: A Case Study from Milan, Italy. Urban Science 2021, 5, 64 .
AMA StyleTania Contardo, Stefano Gazzotti, Marco Aldo Ortenzi, Andrea Vannini, Stefano Loppi. Biological Effects of Air Pollution on Sensitive Bioindicators: A Case Study from Milan, Italy. Urban Science. 2021; 5 (3):64.
Chicago/Turabian StyleTania Contardo; Stefano Gazzotti; Marco Aldo Ortenzi; Andrea Vannini; Stefano Loppi. 2021. "Biological Effects of Air Pollution on Sensitive Bioindicators: A Case Study from Milan, Italy." Urban Science 5, no. 3: 64.
The first example of solvent-free, organocatalyzed, polymerization of 1,3-dioxolan-4-ones, used as easily accessible monomers for the synthesis of polylactic acid (PLA), is described here. An optimization of reaction conditions was carried out, with p-toluensulfonic acid emerging as the most efficient Brønsted acid catalyst. The reactivity of the monomers in the tested conditions was studied following the monomer conversion by 1H NMR and the molecular weight growth by SEC analysis. A double activation polymerization mechanism was proposed, pointing out the key role of the acid catalyst. The formation of acetal bridges was demonstrated, to different extents depending on the nature of the aldehyde or ketone employed for lactic acid protection. The polymer shows complete retention of stereochemistry, as well as good thermal properties and good polydispersity, albeit modest molecular weight.
Stefano Gazzotti; Marco Aldo Ortenzi; Hermes Farina; Alessandra Silvani. 1,3-Dioxolan-4-Ones as Promising Monomers for Aliphatic Polyesters: Metal-Free, in Bulk Preparation of PLA. Polymers 2020, 12, 2396 .
AMA StyleStefano Gazzotti, Marco Aldo Ortenzi, Hermes Farina, Alessandra Silvani. 1,3-Dioxolan-4-Ones as Promising Monomers for Aliphatic Polyesters: Metal-Free, in Bulk Preparation of PLA. Polymers. 2020; 12 (10):2396.
Chicago/Turabian StyleStefano Gazzotti; Marco Aldo Ortenzi; Hermes Farina; Alessandra Silvani. 2020. "1,3-Dioxolan-4-Ones as Promising Monomers for Aliphatic Polyesters: Metal-Free, in Bulk Preparation of PLA." Polymers 12, no. 10: 2396.
1,3-Dioxolan-4-one (DOX) chemistry was exploited for the synthesis of poly(lactic acid) (PLA)-based copolymers. A new DOX monomer, bearing the naturally occurring carvacrol (CarvDOX) as a pendant, was synthesized and used as a model for the optimization of DOX-l-lactide, solvent-free, copolymerization reactions. A screening of conditions was carried out to find out the best catalytic system for both comonomers at the same time, as well as to maximize the growth of the molecular weight. The optimized copolymerization conditions were then applied to a second DOX derivative (CardDOX), bearing the naturally occurring 3-pentacylphenol (cardanol), as an appendage. Various copolymers between l-lactide and different amounts of CarvDOX or CardDOX were prepared and characterized through NMR and wide-angle X-ray scattering (WAXS), also assessing their thermal properties via differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). To exploit the potential use of such copolymers as functional additives in poly(lactic acid) (PLA), they were blended via solvent mixing with commercial PLA and the melt viscosity properties of the resulting blends were investigated through frequency sweep experiments.
Stefano Gazzotti; Marco Aldo Ortenzi; Hermes Farina; Mariapina Disimino; Alessandra Silvani. Carvacrol- and Cardanol-Containing 1,3-Dioxolan-4-ones as Comonomers for the Synthesis of Functional Polylactide-Based Materials. Macromolecules 2020, 53, 6420 -6431.
AMA StyleStefano Gazzotti, Marco Aldo Ortenzi, Hermes Farina, Mariapina Disimino, Alessandra Silvani. Carvacrol- and Cardanol-Containing 1,3-Dioxolan-4-ones as Comonomers for the Synthesis of Functional Polylactide-Based Materials. Macromolecules. 2020; 53 (15):6420-6431.
Chicago/Turabian StyleStefano Gazzotti; Marco Aldo Ortenzi; Hermes Farina; Mariapina Disimino; Alessandra Silvani. 2020. "Carvacrol- and Cardanol-Containing 1,3-Dioxolan-4-ones as Comonomers for the Synthesis of Functional Polylactide-Based Materials." Macromolecules 53, no. 15: 6420-6431.
Polylactide (PLA)-based polymers, functionalized with biobased antioxidants, were synthesized, to develop an intrinsically active, biobased and potentially biodegradable material for food packaging applications. To achieve this result, phenolic antioxidants were exploited as initiators in the ring opening polymerization of l-lactide. The molecular weight, thermal properties and in vitro radical scavenging activity of the polymers obtained were compared with the ones of a PLA Natureworks 4043D, commonly used for flexible food packaging applications. The most promising synthesized polymer, bearing vanillyl alcohol as initiator (PLA-VA), was evaluated for active food packaging applications. Packaging with PLA-VA films reduced color and fat oxidation of salami during its shelf life.
Marco Aldo Ortenzi; Stefano Gazzotti; Begonya Marcos; Stefano Antenucci; Stefano Camazzola; Luciano Piergiovanni; Hermes Farina; Giuseppe Di Silvestro; Luisella Verotta. Synthesis of Polylactic Acid Initiated through Biobased Antioxidants: Towards Intrinsically Active Food Packaging. Polymers 2020, 12, 1183 .
AMA StyleMarco Aldo Ortenzi, Stefano Gazzotti, Begonya Marcos, Stefano Antenucci, Stefano Camazzola, Luciano Piergiovanni, Hermes Farina, Giuseppe Di Silvestro, Luisella Verotta. Synthesis of Polylactic Acid Initiated through Biobased Antioxidants: Towards Intrinsically Active Food Packaging. Polymers. 2020; 12 (5):1183.
Chicago/Turabian StyleMarco Aldo Ortenzi; Stefano Gazzotti; Begonya Marcos; Stefano Antenucci; Stefano Camazzola; Luciano Piergiovanni; Hermes Farina; Giuseppe Di Silvestro; Luisella Verotta. 2020. "Synthesis of Polylactic Acid Initiated through Biobased Antioxidants: Towards Intrinsically Active Food Packaging." Polymers 12, no. 5: 1183.
The information concerning the toxicity of sinking microplastics (MPs) on benthic marine animals, particularly benthic grazers, is still scant. No study focused on biological weathering of sinked MPs operated by benthic organisms. This study aims at investigating the ingestion and the effects induced by 7-days dietary exposure to environmentally relevant amount (8, 80 and 800 particles/g of food) of irregular shaped and sized (diameter 12.6−1,065 µm; mean diameter 316 ± 12 µm) polyethylene terephthalate microplastics (PET-MPs) on a common marine benthic grazer, the sea urchin Paracentrotus lividus. Adverse effects were investigated on digestive tract at biochemical (oxidative stress biomarkers) and tissue level (histopathological analyses). Potential alteration of MP structure/surface and PET macromolecules due to the ingestion of PET-MPs within the sea urchin digestive tract were investigated. Results showed that PET-MPs were efficiently egested by sea urchins without producing histological alterations on digestive tract tissues, only inducing a slight modulation of oxidative status. Sea urchin grazing activity and the related transit of PET-MPs within animal digestive tract slightly affected MP structure and PET composition. These findings suggest that PET-MPs might represent an hazard for benthic grazer organisms, which can partially contribute to the degradation of PET in marine ecosystems.
Marco Parolini; Cinzia Ferrario; Beatrice De Felice; Stefano Gazzotti; Francesco Bonasoro; Maria Daniela Candia Carnevali; Marco Aldo Ortenzi; Michela Sugni. Interactive effects between sinking polyethylene terephthalate (PET) microplastics deriving from water bottles and a benthic grazer. Journal of Hazardous Materials 2020, 398, 122848 .
AMA StyleMarco Parolini, Cinzia Ferrario, Beatrice De Felice, Stefano Gazzotti, Francesco Bonasoro, Maria Daniela Candia Carnevali, Marco Aldo Ortenzi, Michela Sugni. Interactive effects between sinking polyethylene terephthalate (PET) microplastics deriving from water bottles and a benthic grazer. Journal of Hazardous Materials. 2020; 398 ():122848.
Chicago/Turabian StyleMarco Parolini; Cinzia Ferrario; Beatrice De Felice; Stefano Gazzotti; Francesco Bonasoro; Maria Daniela Candia Carnevali; Marco Aldo Ortenzi; Michela Sugni. 2020. "Interactive effects between sinking polyethylene terephthalate (PET) microplastics deriving from water bottles and a benthic grazer." Journal of Hazardous Materials 398, no. : 122848.
The application of various isonitrile-based multicomponent reactions to protected (2-oxoethyl)boronic acid (as the carbonyl component) is described. The Ugi reaction, both in the four components and in the four centers–three components versions, and the van Leusen reaction, proved effective at providing small libraries of MIDA-protected β-aminoboronic acids. The corresponding free β-aminoboronic acids, quantitatively recovered through basic mild deprotection, were found to be quite stable and were fully characterized, including by 11B-NMR spectroscopy. Single-crystal X-ray diffraction analysis, applied both to a MIDA-protected and a free β-aminoboronic acid derivative, provided evidence for different conformations in the solid-state. Finally, the antimicrobial activities of selected compounds were evaluated by measuring their minimal inhibitory concentration (MIC) values, and the binding mode of the most promising derivative on OXA-23 class D β-lactamase was predicted by a molecular modeling study.
Emanuele Bassini; Stefano Gazzotti; Filomena Sannio; Leonardo Lo Presti; Jacopo Sgrignani; Jean-Denis Docquier; Giovanni Grazioso; Alessandra Silvani. Isonitrile-Based Multicomponent Synthesis of β-Amino Boronic Acids as β-Lactamase Inhibitors. Antibiotics 2020, 9, 249 .
AMA StyleEmanuele Bassini, Stefano Gazzotti, Filomena Sannio, Leonardo Lo Presti, Jacopo Sgrignani, Jean-Denis Docquier, Giovanni Grazioso, Alessandra Silvani. Isonitrile-Based Multicomponent Synthesis of β-Amino Boronic Acids as β-Lactamase Inhibitors. Antibiotics. 2020; 9 (5):249.
Chicago/Turabian StyleEmanuele Bassini; Stefano Gazzotti; Filomena Sannio; Leonardo Lo Presti; Jacopo Sgrignani; Jean-Denis Docquier; Giovanni Grazioso; Alessandra Silvani. 2020. "Isonitrile-Based Multicomponent Synthesis of β-Amino Boronic Acids as β-Lactamase Inhibitors." Antibiotics 9, no. 5: 249.
In this work, three types of cellulose nanocrystals (CNCs) were used: CNCSO3H extracted from wood pulp by sulfuric acid (H2SO4), CNCCOOH extracted from cotton linters by ammonium persulfate (APS) and CNCCOOR obtained by esterification of the previous two CNCCOOH and CNCSO3H. For a comparative assessment of gas barrier performance, plastic films such as PLA, PET, PE, PP, OPP and OPA were selected, coated with the three types of CNCs and finally laminated with a solvent-based polyurethanic adhesive. First, all dispersed CNCs were characterized by apparent hydrodynamic diameter and Z potential by means of dynamic light scattering (DLS) and electrophoretic light scattering (ELS) techniques, respectively, followed by the crystallinity index (XRD), thermogravimetric analysis (TGA) and evaluation of Fourier-transform infrared spectroscopy (FTIR), as well as the charges density. The surface chemistry of coated plastics (CNCs-P) was assessed by the Z potential through the electrokinetic technique (streaming potential method) and the optical contact angle (OCA). Lastly, laminated films (P-CNC-P) were evaluated by gas permeability measurements at 23 °C and 50–80% RH. It is worth noting that improvements between 90% and 100% of oxygen barrier were achieved after the lamination. This paper provides insights on the choice of cellulosic nanomaterials for the design and development of advanced and sustainable food packaging materials.
Ghislain Fotie; Stefano Gazzotti; Marco Aldo Ortenzi; Luciano Piergiovanni. Implementation of High Gas Barrier Laminated Films Based on Cellulose Nanocrystals for Food Flexible Packaging. Applied Sciences 2020, 10, 3201 .
AMA StyleGhislain Fotie, Stefano Gazzotti, Marco Aldo Ortenzi, Luciano Piergiovanni. Implementation of High Gas Barrier Laminated Films Based on Cellulose Nanocrystals for Food Flexible Packaging. Applied Sciences. 2020; 10 (9):3201.
Chicago/Turabian StyleGhislain Fotie; Stefano Gazzotti; Marco Aldo Ortenzi; Luciano Piergiovanni. 2020. "Implementation of High Gas Barrier Laminated Films Based on Cellulose Nanocrystals for Food Flexible Packaging." Applied Sciences 10, no. 9: 3201.
Microplastic (MP) contamination represents a serious threat for marine organisms. Several lab studies demonstrated adverse effects induced by exposure to different MP polymers toward diverse marine species. However, the information regarding toxicity of polyethylene terephthalate (PET) MPs is largely unknown. The present study was aimed at investigating the adverse effects induced by 7-day exposure to two concentrations (0.125 or 12.5 µg/ml) micronized, irregular shaped and variable size PET microparticles (PET-MPs) toward Manila clam (Ruditapes philippinarum). Histological analyses were performed to assess tissue damage on digestive glands, gonads, gut and gills, whereas oxidative stress-related effects, including the concentration of pro-oxidant molecules, activity of antioxidant (superoxide dismutase – SOD, catalase – CAT and glutathione peroxidase – GPx) and detoxifying (glutathione S-transferase – GST) enzymes, as well as levels of lipid peroxidation, were determined in gills and digestive gland. Our results showed that clams ingest and egest micronized PET-MPs, but no marked histological alterations to bivalve tissues occurred. Although PET-MPs did not produce oxidative stress in the digestive gland, these materials significantly altered oxidative status of gills, leading to lipid peroxidation. No apparent clear indication of a weakness of bivalve health status was obtained in this study.
Marco Parolini; Beatrice DE Felice; Stefano Gazzotti; Luisa Annunziata; Michela Sugni; Renato Bacchetta; Marco Aldo Ortenzi. Oxidative stress-related effects induced by micronized polyethylene terephthalate microparticles in the Manila clam. Journal of Toxicology and Environmental Health, Part A 2020, 83, 168 -179.
AMA StyleMarco Parolini, Beatrice DE Felice, Stefano Gazzotti, Luisa Annunziata, Michela Sugni, Renato Bacchetta, Marco Aldo Ortenzi. Oxidative stress-related effects induced by micronized polyethylene terephthalate microparticles in the Manila clam. Journal of Toxicology and Environmental Health, Part A. 2020; 83 (4):168-179.
Chicago/Turabian StyleMarco Parolini; Beatrice DE Felice; Stefano Gazzotti; Luisa Annunziata; Michela Sugni; Renato Bacchetta; Marco Aldo Ortenzi. 2020. "Oxidative stress-related effects induced by micronized polyethylene terephthalate microparticles in the Manila clam." Journal of Toxicology and Environmental Health, Part A 83, no. 4: 168-179.
In contrast to conventional approaches, which are considered to be energy- and time-intensive, expensive, and not green, herein, we report an alternative microwave-assisted ammonium persulfate (APS) method for cellulose nanocrystals (CNCs) production, under pressurized conditions in a closed reaction system. The aim was to optimize the hydrolytic-oxidative patented procedure (US 8,900,706), replacing the conventional heating with a faster process that would allow the industrial scale production of the nanomaterial and make it more appealing to a green economy. A microwave-assisted process was performed according to different time–temperature programs, varying the ramp (from 5 to 40 min) and the hold heating time (from 60 to 90 min), at a fixed reagent concentration and weight ratio of the raw material/APS solution. Differences in composition, structure, and morphology of the nanocrystals, arising from traditional and microwave methods, were studied by several techniques (TEM, Fourier transform infrared spectroscopy (FTIR)-attenuated total reflectance (ATR), dynamic light scattering (DLS), electrophoretic light scattering (ELS), thermogravimetric analysis (TGA), X-ray diffraction (XRD)), and the extraction yields were calculated. Fine tuning the microwave treatment variables, it was possible to realize a simple, cost-effective way for faster materials’ preparation, which allowed achieving high-quality CNCs, with a defined hydrodynamic diameter (150 nm) and zeta potential (−0.040 V), comparable to those obtained using conventional heating, in only 90 min instead of 16 h.
Luana Amoroso; Giuseppe Muratore; Marco Aldo Ortenzi; Stefano Gazzotti; Sara Limbo; Luciano Piergiovanni. Fast Production of Cellulose Nanocrystals by Hydrolytic-Oxidative Microwave-Assisted Treatment. Polymers 2020, 12, 68 .
AMA StyleLuana Amoroso, Giuseppe Muratore, Marco Aldo Ortenzi, Stefano Gazzotti, Sara Limbo, Luciano Piergiovanni. Fast Production of Cellulose Nanocrystals by Hydrolytic-Oxidative Microwave-Assisted Treatment. Polymers. 2020; 12 (1):68.
Chicago/Turabian StyleLuana Amoroso; Giuseppe Muratore; Marco Aldo Ortenzi; Stefano Gazzotti; Sara Limbo; Luciano Piergiovanni. 2020. "Fast Production of Cellulose Nanocrystals by Hydrolytic-Oxidative Microwave-Assisted Treatment." Polymers 12, no. 1: 68.
The indium-mediated allylation of novel 3-(2-Boc-hydrazono)indolin-2-one derivatives, followed by a palladium-catalysed carboamination reaction, is described to afford unprecedented spirocyclic oxindoles in good yields.
Stefano Gazzotti; Marco Manenti; Leonardo Lo Presti; Alessandra Silvani. Allylation of isatin-derived N-Boc-hydrazones followed by Pd-catalyzed carboamination reaction: an entry to 3-spiro-pyrazolidyl-oxindoles. RSC Advances 2019, 9, 37788 -37800.
AMA StyleStefano Gazzotti, Marco Manenti, Leonardo Lo Presti, Alessandra Silvani. Allylation of isatin-derived N-Boc-hydrazones followed by Pd-catalyzed carboamination reaction: an entry to 3-spiro-pyrazolidyl-oxindoles. RSC Advances. 2019; 9 (65):37788-37800.
Chicago/Turabian StyleStefano Gazzotti; Marco Manenti; Leonardo Lo Presti; Alessandra Silvani. 2019. "Allylation of isatin-derived N-Boc-hydrazones followed by Pd-catalyzed carboamination reaction: an entry to 3-spiro-pyrazolidyl-oxindoles." RSC Advances 9, no. 65: 37788-37800.
Introduction: Multicomponent reactions are paramount in drug discovery for their ability to achieve high levels of diversity within the chemical space, generating complex structures from simple building blocks. Among them, the isocyanide-based Ugi-Joulliè reaction is particularly suited for the rapid synthesis of peptidomimetics and nitrogen-containing compounds. Areas covered: The latest achievements in drug discovery and synthetic chemistry regarding the application of the Ugi-Joulliè reaction in the field of natural compounds, peptidomimetics and small molecules, are reported in this article. All relevant literature was disclosed applying most common web-based literature searching tools, namely Web of Science, PubMed, SciFinder and Google Scholar. Expert opinion: The Ugi-Joulliè reaction represents an extremely versatile and simple synthetic methodology, useful for designing efficiently new molecular frameworks. Particularly relevant to drug discovery is the Ugi-Joulliè-based synthesis of conformationally constrained peptidomimetics and antibacterial depsipeptides. On the other hand, the many syntheses of new, nitrogen-containing heterocycles are not always followed by biological evaluation, losing opportunities for the disclosure of unprecedented lead compounds.
Stefano Gazzotti; Giulia Rainoldi; Alessandra Silvani. Exploitation of the Ugi–Joullié reaction in drug discovery and development. Expert Opinion on Drug Discovery 2019, 14, 639 -652.
AMA StyleStefano Gazzotti, Giulia Rainoldi, Alessandra Silvani. Exploitation of the Ugi–Joullié reaction in drug discovery and development. Expert Opinion on Drug Discovery. 2019; 14 (7):639-652.
Chicago/Turabian StyleStefano Gazzotti; Giulia Rainoldi; Alessandra Silvani. 2019. "Exploitation of the Ugi–Joullié reaction in drug discovery and development." Expert Opinion on Drug Discovery 14, no. 7: 639-652.
PLA-based materials with eugenol moieties covalently bonded to the macromolecular chains were synthesized for potential application in bioactive food packaging. The synthetic strategy relies on the exploitation of O-Carboxyanhydrides (OCAs) as versatile and easily modifiable monomers. More precisely, eugenol-bearing L-malic acid-derived OCA (L-MalOCA) was synthesized and used as monomer, in homo- and co-polymerization reactions. In the latter case, two different ratios of functionalized L-MalOCA were employed, with respect to the standard L-lactic acid-derived OCA (L-LacOCA) monomer. Homopolymer and copolymers were fully characterized and their thermal properties were investigated, highlighting the effect on the final polymer of varying the concentration of the L-MalOCA-derived monomer. A moderate antimicrobial activity was detected for the eugenol-rich L-MalOCA-derived homopolymerization product, making it promising for developments in the field of bioactive and biodegradable PLA-based materials.
Stefano Gazzotti; Simona Alessandra Todisco; Claudia Picozzi; Marco Aldo Ortenzi; Hermes Farina; Giordano Lesma; Alessandra Silvani. Eugenol-grafted aliphatic polyesters: Towards inherently antimicrobial PLA-based materials exploiting OCAs chemistry. European Polymer Journal 2019, 114, 369 -379.
AMA StyleStefano Gazzotti, Simona Alessandra Todisco, Claudia Picozzi, Marco Aldo Ortenzi, Hermes Farina, Giordano Lesma, Alessandra Silvani. Eugenol-grafted aliphatic polyesters: Towards inherently antimicrobial PLA-based materials exploiting OCAs chemistry. European Polymer Journal. 2019; 114 ():369-379.
Chicago/Turabian StyleStefano Gazzotti; Simona Alessandra Todisco; Claudia Picozzi; Marco Aldo Ortenzi; Hermes Farina; Giordano Lesma; Alessandra Silvani. 2019. "Eugenol-grafted aliphatic polyesters: Towards inherently antimicrobial PLA-based materials exploiting OCAs chemistry." European Polymer Journal 114, no. : 369-379.
One-pot in situ polymerization approach was explored for the preparation of polylactide (PLA)-cellulose nanofibril (CNF) bio-nanocomposites. CNF were first prepared through enzymatic and mechanical treatment of bleached hardwood kraft pulp. The bio-nanocomposites- were then fabricated through ring opening polymerization (ROP) of L-lactide, in the presence of various amounts of fibrils. Molecular weight, thermal properties, surface morphology, mechanical and wettability properties of the PLA-CNF nanocomposites were evaluated. DSC analysis demonstrated the effect of CNF on crystallization and crystalline morphology of PLA. Improved modulus for the nanocomposites with respect to standard PLA was demonstrated, however, the differences in tensile stress were small probably due to the counteracting effects of reinforcement from CNF and the decreasing molecular weight as a function of CNF concentration. The absence of pulled-out fibers was assessed, highlighting the strong interface and covalent attachment of PLA chains on CNF surface. Finally, the covalent bonding of PLA chains on CNF surface was demonstrated by isolating the non-soluble part, consisting of PLA-grafted CNF, and characterization of this residue.
Stefano Gazzotti; Riccardo Rampazzo; Minna Hakkarainen; Daniele Bussini; Marco Aldo Ortenzi; Hermes Farina; Giordano Lesma; Alessandra Silvani. Cellulose nanofibrils as reinforcing agents for PLA-based nanocomposites: An in situ approach. Composites Science and Technology 2018, 171, 94 -102.
AMA StyleStefano Gazzotti, Riccardo Rampazzo, Minna Hakkarainen, Daniele Bussini, Marco Aldo Ortenzi, Hermes Farina, Giordano Lesma, Alessandra Silvani. Cellulose nanofibrils as reinforcing agents for PLA-based nanocomposites: An in situ approach. Composites Science and Technology. 2018; 171 ():94-102.
Chicago/Turabian StyleStefano Gazzotti; Riccardo Rampazzo; Minna Hakkarainen; Daniele Bussini; Marco Aldo Ortenzi; Hermes Farina; Giordano Lesma; Alessandra Silvani. 2018. "Cellulose nanofibrils as reinforcing agents for PLA-based nanocomposites: An in situ approach." Composites Science and Technology 171, no. : 94-102.
1,3-dioxolan-4-one (DOX) chemistry was explored for production of “one-pot” biobased polyester thermosets. DOX monomer was first functionalized by naturally occurring eugenol to introduce a structural element, which could induce crosslinking reaction through cationic polymerization of the double bond. The feasibility of polymerizing DOX monomers bearing bulky side groups was proved by model phenol-substituted DOX monomer (PhDOX). Once the reaction was shown to be effective, the same protocol was applied to eugenol-substituted monomer (EuDOX). A brief screening of the optimal catalyst concentration was performed, to obtain a highly crosslinked product. The synthesized thermoset showed good thermal resistance and high mechanical strength probably due to the rich aromatic content. The obtained thermoset was further subjected to microwave-assisted hydrothermal degradation test, which demonstrated complete recyclability to water or methanol soluble products. NMR and MALDI-MS analysis of the obtained degradation products unveiled the structure of the thermoset strongly indicating that the polymerization of eugenol functionalized DOX monomer resulted in polylactide-like chains connected with aromatic-aliphatic segments resulting from the reaction of the eugenol double bonds. The presence of free hydroxyl and carboxyl groups shed light to the mechanism behind the observed shape-memory and self-healing properties.
Stefano Gazzotti; Minna Hakkarainen; Karin H. Adolfsson; Marco Aldo Ortenzi; Hermes Farina; Giordano Lesma; Alessandra Silvani. One-Pot Synthesis of Sustainable High-Performance Thermoset by Exploiting Eugenol Functionalized 1,3-Dioxolan-4-one. ACS Sustainable Chemistry & Engineering 2018, 6, 15201 -15211.
AMA StyleStefano Gazzotti, Minna Hakkarainen, Karin H. Adolfsson, Marco Aldo Ortenzi, Hermes Farina, Giordano Lesma, Alessandra Silvani. One-Pot Synthesis of Sustainable High-Performance Thermoset by Exploiting Eugenol Functionalized 1,3-Dioxolan-4-one. ACS Sustainable Chemistry & Engineering. 2018; 6 (11):15201-15211.
Chicago/Turabian StyleStefano Gazzotti; Minna Hakkarainen; Karin H. Adolfsson; Marco Aldo Ortenzi; Hermes Farina; Giordano Lesma; Alessandra Silvani. 2018. "One-Pot Synthesis of Sustainable High-Performance Thermoset by Exploiting Eugenol Functionalized 1,3-Dioxolan-4-one." ACS Sustainable Chemistry & Engineering 6, no. 11: 15201-15211.
This article describes for the first time the pseudo-living radical activity of 4-vinyl-1,3-dioxolane-2-one (VEC) monomer towards a free radical homo-polymerization: a kinetic study of VEC homo-polymerization was performed up to 168 hours and it was found that molecular weights, determined via gel permeation chromatography (GPC), and VEC conversion, measured via 1H NMR spectroscopy, continue to grow over time showing a molecular weights distribution typical of pseudo-living polymerizations.Until today, in co-polymerization with styrene, just a few VEC moieties could be inserted into VEC-styrene co-polymers; in this work VEC controlled radical activity allows, for the first time, the synthesis of di-block co-polymers between styrene and vinyl groups bearing cyclic carbonate functionalities that can be used for further cross-linking reactions. VEC-styrene co-polymers were synthesized with different molar ratios between co-monomers and characterized by GPC analyses and 1H NMR spectra; excellent reaction yields and solubility in apolar solvents were obtained.
Valentina Sabatini; Stefano Gazzotti; Hermes Farina; Stefano Camazzola; Marco A. Ortenzi. The Case of 4-Vinyl-1,3-dioxolane-2-one: Determination of Its Pseudo-Living Behavior and Preparation of Allyl Carbonate-Styrene Co-Polymers. ChemistrySelect 2017, 2, 10748 -10753.
AMA StyleValentina Sabatini, Stefano Gazzotti, Hermes Farina, Stefano Camazzola, Marco A. Ortenzi. The Case of 4-Vinyl-1,3-dioxolane-2-one: Determination of Its Pseudo-Living Behavior and Preparation of Allyl Carbonate-Styrene Co-Polymers. ChemistrySelect. 2017; 2 (33):10748-10753.
Chicago/Turabian StyleValentina Sabatini; Stefano Gazzotti; Hermes Farina; Stefano Camazzola; Marco A. Ortenzi. 2017. "The Case of 4-Vinyl-1,3-dioxolane-2-one: Determination of Its Pseudo-Living Behavior and Preparation of Allyl Carbonate-Styrene Co-Polymers." ChemistrySelect 2, no. 33: 10748-10753.
Stefano Gazzotti; Hermes Farina; Giordano Lesma; Riccardo Rampazzo; Luciano Piergiovanni; Marco Aldo Ortenzi; Alessandra Silvani. Polylactide/cellulose nanocrystals: The in situ polymerization approach to improved nanocomposites. European Polymer Journal 2017, 94, 173 -184.
AMA StyleStefano Gazzotti, Hermes Farina, Giordano Lesma, Riccardo Rampazzo, Luciano Piergiovanni, Marco Aldo Ortenzi, Alessandra Silvani. Polylactide/cellulose nanocrystals: The in situ polymerization approach to improved nanocomposites. European Polymer Journal. 2017; 94 ():173-184.
Chicago/Turabian StyleStefano Gazzotti; Hermes Farina; Giordano Lesma; Riccardo Rampazzo; Luciano Piergiovanni; Marco Aldo Ortenzi; Alessandra Silvani. 2017. "Polylactide/cellulose nanocrystals: The in situ polymerization approach to improved nanocomposites." European Polymer Journal 94, no. : 173-184.
Cellulose nanocrystals (CNCs) are unique, renewable top-down nano particles from which coatings with improved gas barrier properties and new functionalities can be prepared. In this paper, the potential for obtaining such high performing nanocrystals from low-cost lignocellulosic by-products or raw materials is proved by a comparison study on CNCs obtained both from cotton linters and kraft pulp, by means of the ammonium persulfate (APS) process. Morphological and chemical characterization of the nanocrystals obtained, as well as the main functional properties of the poly(ethylene terephthalate) coated films, showed quite similar characteristics and performances of CNCs obtained from pure cellulose raw material (cotton linters) and the nanoparticles produced from a potential discard of paper making processes (kraft pulp). In particular, the gas barrier properties of the coating produced with CNCs obtained from kraft pulp were very promising, providing oxygen and carbon dioxide permeability values hundreds of times lower than those of equal thickness in comparison with common barrier synthetic polymers, over a broad range of temperatures. The results obtained are relevant not only for the outstanding performances achieved, but also because they evoke a possible positive example of industrial symbiosis in the packaging field, merging together the requirements and needs of the paper and plastic industries and addressing the way towards a better management of waste and materials. Copyright © 2017 John Wiley & Sons, Ltd.
Riccardo Rampazzo; Derya Alkan; Stefano Gazzotti; Marco Aldo Ortenzi; Giulio Piva; Luciano Piergiovanni. Cellulose Nanocrystals from Lignocellulosic Raw Materials, for Oxygen Barrier Coatings on Food Packaging Films. Packaging Technology and Science 2017, 30, 645 -661.
AMA StyleRiccardo Rampazzo, Derya Alkan, Stefano Gazzotti, Marco Aldo Ortenzi, Giulio Piva, Luciano Piergiovanni. Cellulose Nanocrystals from Lignocellulosic Raw Materials, for Oxygen Barrier Coatings on Food Packaging Films. Packaging Technology and Science. 2017; 30 (10):645-661.
Chicago/Turabian StyleRiccardo Rampazzo; Derya Alkan; Stefano Gazzotti; Marco Aldo Ortenzi; Giulio Piva; Luciano Piergiovanni. 2017. "Cellulose Nanocrystals from Lignocellulosic Raw Materials, for Oxygen Barrier Coatings on Food Packaging Films." Packaging Technology and Science 30, no. 10: 645-661.