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According to the 2021 World Drug Report, around 275 million people use drugs of abuse, and 36 million people suffer from addiction, fostering a thriving market for illicit substances. In Italy, 30,083 people were reported to the Judicial Authority for offenses in violation of the Italian Law D.P.R. 309/1990. These offences are sentenced after a qualitative–quantitative analysis of seized materials. Given the large quantity of seized drugs and the need to perform accurate analytical determinations, Italian forensic laboratories struggle to complete analyses in a short time, delaying the entire reporting process needed to achieve sentencing. For this purpose, an UHPLC-MS/MS-based platform was developed at the University of Milano-Bicocca to support law-enforcement authorities. Software was designed to easily manage street seizure acquisition, documentation registration, and sampling. A sensitive UHPLC-MS/MS method was fully validated for the quantification of the traditional illicit substances (cocaine, heroin, 6-MAM, morphine, amphetamine, methamphetamine, MDMA, ketamine, GHB, GBL, LSD, trans-∆9-THC, and THCA) at the ppb level. The final report is relayed to the Prefecture in 3–4 days, even within 24 h for urgent requests. The platform allows for semi-automatic data handling to minimize erroneous results for an accurate report generation by standardized procedures.

La metabolomica, che consiste nella identificazione di tutti i metaboliti presenti all’interno dei campioni biologici analizzati, è un approccio ampiamente applicato in diversi campi di ricerca quali: identificazione di biomarcatori, sviluppo di nuovi farmaci, scienze alimentari e ambientali. La metabolomica è strettamente legata alla capacità di tecniche analitiche fra queste una delle più applicate è la gas cromatografia accoppiata alla spettrometria di massa. Moderne piattaforme analitiche possono generare centinaia di migliaia di spettri, rilevando una quantità impressionante di molecole distinte. Nonostante i progressi tecnici raggiunti sul lato sperimentale, la conversione dei segnali misurati dagli strumenti in informazioni utili non è un passaggio scontato in studi metabolomici. Per ogni composto identificato, l’obbiettivo è ottenere la concentrazione relativa tra tutti i campioni analizzati e lo spettro di massa associato al composto, necessario per l’identificazione della molecola stessa. I software disponibili per l’analisi dei dati sperimentali sono stati ripetutamente indicati come una fonte importante di incertezza, limitando fortemente sia la quantità che la qualità delle informazioni estratte. Gli strumenti più applicati richiedono l’impostazione di diversi parametri da parte dell’operatore, influenzando il risultato dell’analisi. In questa tesi è descritto un nuovo approccio, chiamato AutoDise, per l’analisi dei dati GC-MS. L’elaborazione dei segnali sperimentali si basa su PARAFAC2. PARAFAC2 è un modello che scompone dati multidimensionali, discriminando tra i diversi segnali nei campioni. Grazie alle sue proprietà, PARAFAC2 non ha bisogno che i dati siano pretrattati e non richiede di impostare parametri, mentre software utilizzati in questo ambito richiedono di definire diversi parametri e un laborioso pretrattamento dei dati, richiedendo l’intervento di un utente esperto, inoltre la riproducibilità dei risultati è limitata, dipen, Metabolomics, which consists of identifying all the metabolites present in the biological samples analysed, is an approach widely applied in various research fields such as biomarker identification, new drug development, food and environmental sciences. Metabolomics is closely linked to the ability of analytical techniques, one of the most widely applied being gas chromatography coupled to mass spectrometry. Modern analytical platforms can generate hundreds of thousands of spectra, detecting an impressive number of distinct molecules. Despite the technical progress achieved on the experimental side, the conversion of signals measured by instruments into useful information is not an obvious step in metabolomic studies. For each identified compound, the goal is to obtain the relative concentration among all analysed samples and the mass spectrum associated with the compound needed to identify the molecule itself. The software available for analysing experimental data has repeatedly been cited as a major source of uncertainty, severely limiting both the quantity and quality of the information extracted. The most applied tools are based on univariate data analysis, considering each sample separately from the others and requiring the operator to set several parameters, affecting the result of the analysis. In this thesis, a new approach, called AutoDise, for the analysis of GC-MS data is described. The processing of the experimental signals is based on PARAFAC2. PARAFAC2 is a model that decomposes multidimensional data, discriminating between different signals in the samples. Due to its properties, PARAFAC2 does not need the data to be pre-processed and does not require parameters to be set, whereas software used in this field requires several parameters to be defined and laborious pre-processing of the data, requiring the intervention of an expert user, and the reproducibility of the results is limited, depending on the parameters chosen by the user. However, fitting PA

L’insufficienza cardiaca è una sindrome di grande rilevanza clinica nella quale il muscolo cardiaco non è in grado di pompare il sangue efficacemente nel corpo. Per il trattamento dei pazienti si ricorre, principalmente, ai glicosidi cardiaci o digitalici come la digossina, che svolgono la loro azione inibendo la pompa Na+/K+ e, conseguentemente, aumentando la concentrazione del calcio, favorendo una migliore contrazione. Il calcio viene però accumulato in alte concentrazioni nella cellula provocando nei pazienti cronici aritmie che possono portare, comunque, alla morte del paziente. Pertanto, lo scopo di questa tesi tesi è stato quello di sintetizzare nuovi candidati farmaci (drug leads) per il trattamento dell’insufficienza cardiaca che abbiano la stessa attività dei digitalici con indice terapeutico maggiore e minor tossicità, garantendo l’assenza di aritmie nei pazienti cronici. Il disegno delle molecole realizzate durante il periodo di tesi è partito dalla struttura chimica della molecola istaroxime: questo composto è attualmente in fase clinica III come farmaco cardiaco. Istaroxime è in grado di inibire efficacemente la pompa Na+/K+ evitando, allo stesso tempo, la comparsa di aritmie grazie alla sua azione stimolante su SERCA-2°, una proteina di membrana in grado di sequestrare il calcio citosolico durante il rilassamento cardiaco. Lo studio dei metaboliti di istaroxime ha portato all’identificazione di una molecola in cui il gruppo amminico della catena sull’ossima è stato ossidato a carbossile. Questa molecola, cosiddetta “PST3093”, è in grado di attivare selettivamente SERCA-2a senza inibire, invece, la pompa Na+/K+. Attualmente, questo composto costituisce l’unico candidato farmaco in grado di stimolare il rilassamento cardiaco evitando la comparsa di aritmie. Tuttavia, sia istaroxime che il suo metabolita presentano delle criticità legate alla presenza della funzionalità ossima, a cui è associata una componente genotossica nei trattamenti cr, Heart failure (HF) is one of the major causes of death in the world. Patients affected by HF presents a pathophysiological state in which the heart is not cable of pumping the blood efficiently in the body due to a loss of contractility of the myocardium, leading to a chronic condition in which oxygen and nutritional need of the body are not satisfied. The most important therapy involves inotropic agents, such as digitals glycosides, capable of improving the cardiac output. The most known digitalis glycoside is Digoxin extracted from Digitalis purpurea. Such compounds acts as inhibitor of the Na+/K+ pump, an active transporter capable of expelling Na+ from the cardiac cells introducing K+ against the natural gradient. The inhibition causes an accumulation of Na+ inside the cell. Sodium is so used from the Na+/Ca++ pump to introduce Ca++ inside the cell. The high concentrations of Ca++ accumulated inside cardiac cells induce contraction of the myocardium. However, digitalis compounds present a small gap between the active concentration and the toxic one. In fact, the over intracellular accumulation for long periods of Ca++ could leads to arrhythmic situations. At today is known only one compound able to stimulate a better contraction without causing arrhythmias, such molecule, called “Istaroxime”. Istaroxime is now under development for the treatment of acute decompensated heart failure. Detailed studies highlighted that a metabolite of Istaroxime, the so-called “PST3093”, acts as a pure activator of SERCA-2a, a protein able to sequestrate Ca2+ from the cytosol, without any action on Na+/K+ pump. PST3093 is the only example in the literature of a pure SERCA-2a activator, making an interesting case of study and a possible first in class drug. Despite the promising activity and the unique characteristic of this compound, there is still the main issue due to the genotoxicity of the carboxy-hydroxylamine formed after oxime degradation by metabolism. Within this thesis, t

Neural networks are rapidly gaining popularity in chemical modeling and Quantitative Structure–Activity Relationship (QSAR) thanks to their ability to handle multitask problems. However, outcomes of neural networks depend on the tuning of several hyperparameters, whose small variations can often strongly affect their performance. Hence, optimization is a fundamental step in training neural networks although, in many cases, it can be very expensive from a computational point of view. In this study, we compared four of the most widely used approaches for tuning hyperparameters, namely, grid search, random search, tree-structured Parzen estimator, and genetic algorithms on three multitask QSAR datasets. We mainly focused on parsimonious optimization and thus not only on the performance of neural networks, but also the computational time that was taken into account. Furthermore, since the optimization approaches do not directly provide information about the influence of hyperparameters, we applied experimental design strategies to determine their effects on the neural network performance. We found that genetic algorithms, tree-structured Parzen estimator, and random search require on average 0.08% of the hours required by grid search; in addition, tree-structured Parzen estimator and genetic algorithms provide better results than random search.

I pneumatici sono realizzati aggiungendo riempitivi alla matrice polimerica. Insieme ad altri additivi, le mescole per pneumatici vengono polimerizzate e modellate. I riempitivi convenzionali utilizzati nel processo sono nerofumo e silice. A causa delle preoccupazioni ambientali associate all'uso di questi riempitivi, in questo lavoro sono stati esplorati polisaccaridi leggeri derivati da fonti biologiche come possibile sostituzione. I riempitivi utilizzati in questo progetto erano nanocristalli di cellulosa e alfa 1,3 glucano. La loro chimica superficiale è simile a quella delle cariche di silice aventi abbondanti gruppi idrossilici superficiali. Questi bio-riempitivi sono idrofili e non compatibili con la matrice polimerica idrofobica come la gomma naturale. A questo proposito, sono stati modificati per essere compatibili con la matrice polimerica. Per ottenere questa modifica, sono stati impiegati due silani: TESPD, APS essendo silani alifatici e SID, SIB essendo silani ciclici. Tutti i composti sono stati confrontati con i composti di silice come riferimento. I risultati ottenuti con queste cariche hanno mostrato che i silani APS favoriscono una vulcanizzazione molto rapida e aumentano la densità di reticolazione. Con questo silano, è stato ottenuto un modulo di stoccaggio più elevato e le proprietà erano migliori rispetto ai composti di silice di riferimento. Lo svantaggio riscontrato con APS è il fatto che una grande quantità di silano influisce sulle proprietà di trazione. Il meccanismo di reazione osservato per i composti TESPD rivela che il modulo di conservazione dei composti con questo silano potrebbe non essere paragonabile a quello di APS, ma le proprietà di trazione erano notevolmente superiori. La decisione su quali silani da utilizzare sarebbe quindi collegata alle proprietà attese che è di interesse. Quando sono stati esplorati i silani ciclici, la loro natura reattiva ha reso la vulcanizzazione veloce. Molto interessante il rinforzo dell, Tires are made by adding fillers to polymeric matrix. Alongside other additives, the tire compounds are cured and shaped. The conventional fillers used in the process is carbon black and silica. Owing to the environmental concerns associated with the use of these fillers, lightweight polysaccharides derived from bio sources were explored in this work as possible replacement. The fillers that were used in this project were cellulose nanocrystals and alpha 1,3 glucan. Their surface chemistry is like that of silica fillers having abundant surface hydroxyl groups. These bio fillers are hydrophilic and not compatible with hydrophobic polymer matrix such as natural rubber. In this regard, they were modified to be compatible with the polymeric matrix. To achieve this modification, two silanes were employed: TESPD, APS being aliphatic silanes and SID, SIB being cyclic silanes. All the compounds were compared with silica compounds as reference. The results obtained with these fillers showed that the APS silanes promote very fast vulcanization and increases the crosslinking density. With this silane, a higher storage modulus was achieved, and properties were better than the reference silica compounds. The drawback that was experience with APS is the fact that large amount of the silane affects the tensile properties. The reaction mechanism observed for TESPD compounds reveals that the storage modulus of the compounds with this silane may not be comparable to that of APS but the tensile properties were remarkably higher. Deciding on which silanes to be used would therefore connect with the expected properties that is of interest. When the cyclic silanes were explored, their reactive nature made the vulcanization to be fast. The reinforcement of the various compounds was very interesting. However, it was observed that at low silane loading between 2-5%, the properties remain fairly the same even when the silane amounts were increased up to 12%. In fact, the cyclic silanes amoun

Le cariche rinforzanti sono i componenti principali dei compositi elastomericie vengono aggiunti per migliorarne le proprietà meccaniche. Il nero di carbonio e la silice sono i filler rinforzanti più comunemente usati nell'industria degli pneumatici a causa dei loro effetti di rinforzo. Nonostante le ottime proprietà conferite, la produzione di nerofumo proviene da combustibili fossili non rinnovabili e l’alta densità della silice rende la densità del prodotto finale piuttosto elevata e influisce negativamente sull'efficienza energetica delle automobili. Questi problemi hanno provocato una crescente richiesta per lo sviluppo di materiali a bassa densità, eco-compatibili, sostenibili e rinnovabili. Le biomasse lignocellulosiche sono emerse come potenziali risorse rinnovabili a causa della loro elevata disponibilità annuale e possono essere frazionate in prodotti a valore aggiunto. Il lavoro presentato in questa tesi è iniziato con il set up di un processo integrato di biorefinery per il recupero simultaneo di lignina, emicellulosa, silice e nanocristalli di cellulosa (CNC) da due biomasse lignocellulosiche: Arundo donax e lolla di riso. I CNC estratti da queste biomasse lignocellulosiche possono essere utilizzati come agente rinforzante grazie alle loro proprietà come la rinnovabilità, la biodegradabilità, la bassa densità, l'elevato aspect ratio e le elevate proprietà meccaniche. È stata studiata la possibilità di utilizzare i CNC in totale o parziale sostituzione della silice nelle mescole di gomma. L'incorporazione di CNC in mescole di gomma è stata effettuata utilizzando tre approcci. Nel primo approccio, la silice è stata parzialmente sostituita con i CNC in composti di gomma naturale preparati mediante miscelazione a secco. Lo studio delle proprietà meccanico/dinamiche e di trazione dei composti preparati ha dimostrato una diminuzione del rinforzo all'aumento del contenuto di CNC. La tendenza dei CNC a formare aggregati a causa dei forti legam, Reinforcing fillers are the primary component of rubber compounds which are added to improve the properties of elastomers. Carbon black and silica are the most commonly used reinforcing fillers in the tire industry due to their outstanding reinforcing effects. Despite the high reinforcing effects, the production of carbon black from non-renewable fossil fuels and high densities of these two fillers make the density of final product relatively high and impart a negative effect on the fuel efficiency of automobiles. These challenges have triggered the increasing concerns for the development of low-density, eco-friendly, sustainable, and renewable materials. Lignocellulosic biomasses have been emerged as potential renewable resources due to their annual renewability and large biomass stock and can be fractionated into value-added products. The work presented in this thesis was started by setting up an integrated biorefinery process for the simultaneous recovery of lignin, hemicelluloses, silica, and cellulose nanocrystals (CNCs) from two lignocellulosic biomasses; Arundo donax and rice husk. The CNCs extracted from these lignocellulosic biomasses can be used as promising reinforcing filler due to their fascinating properties. The feasibility of using CNCs instead of or along with silica in the rubber compounds was studied by investigating the effect of CNCs incorporation on the final properties of the rubber compounds. The incorporation of CNCs in rubber compounds was carried out using three approaches. In the first approach, silica was partially replaced with CNCs in natural rubber compounds prepared through the dry-mixing process. An investigation of the dynamic and tensile mechanical properties of the prepared compounds demonstrated a decrease in the reinforcement of the rubber compounds with the increase of CNCs contents. The tendency of CNCs to form aggregates due to strong hydrogen bonding between hydroxyl groups of CNCs resulted in poor dispersion in the polymer

In this work, cyclocarbonated modified lignin, the most abundant reservoir of aromatic moieties in nature, was used as a green bio-based cross-linker on polyhydroxy urethane formulations. As a preliminary study, a complete 13C NMR characterization of the aminolysis products of cyclocarbonated lignin with 1,12-diaminododecane was provided. The best reaction conditions found for the aminolysis reaction were applied for the preparation of thermoset resins. Cyclocarbonated lignin was then reacted with 1,12-diaminododecane, acting as a chain extender, in the presence of poly(ethylene glycol) bis cyclic carbonate, a soft segment used to tune the resin properties. Different (total cyclocarbonates)/(total amines) equivalent ratios and diverse poly(ethylene glycol)/lignin stoichiometry were tested. The evolution in time of the molecular weight distribution of a selected composition was followed by gel permeation chromatography until the solubility in THF was appreciable. Moreover, some significant resin samples were subjected to DSC analysis to evaluate favourable changes in the glass transition temperature and compared to blank experiments that did not include lignin in the composition

Il lavoro di tesi si colloca nel più ampio progetto del Corimav intitolato materiali elastomerici da fonti rinnovabili. In particolar modo è incentrato sulla valorizzazione di substrati lignocellulosici a basso costo tramite l’ottenimento di prodotti ad elevato valore aggiunto che possono essere utilizzati in sostituzione degli ingredienti tradizionali all’interno di mescole elastomeriche per pneumatici o per l’introduzione di nuove proprietà. In una prima fase del lavoro mi sono occupato della messa a punto di un processo di biorefinery che ci ha consentito di frazionare i substrati di partenza in tre componenti potenzialmente interessanti: lignina, nanocellulosa e silice. Il processo risulta interessante per la possibilità di recuperare simultaneamente tutti e tre i prodotti, con un elevato grado di purezza e una resa discreta. In un secondo memento una modifica del processo di biorefinery ci ha permesso di preparare un materiale ibrido lignina-cellulosa potenzialmente estremamente interessante in quanto combina le caratteristiche della silice (filler di punta nei pneumatici di ultima generazione) e della lignina (rinnovabile, leggera, proprietà antiossidanti). Dopo uno screening iniziale delle proprietà in mescola dei prodotti ottenuti dal frazionamento dei substrati lignocellulosici mi sono concentrato sull’utilizzo della lignina, cercando di migliorare le proprietà meccaniche dei compositi con la gomma naturale. Il lavoro è proseguito su tre fronti: identificazione delle caratteristiche strutturali della lignina che migliorano le proprietà termiche e meccaniche dei composti elastomerici, miglioramento delle proprietà finali mediante modifica della struttura della lignina con diversi trattamenti (frazionamento, processi termici e modifiche chimiche) e ottimizzazione delle caratteristiche del biofiller lignina-silice per aumentarne la capacità di rinforzo., The industrial PhD project was linked to the broader Corimav-Pirelli project named elastomeric materials from renewable resources. The work dealt with the valorization of low value lignocellulosic substrates, focusing on the production of new materials for elastomeric compounds. The target was to produce renewable materials that could be used as a replacement for traditional materials in tyres manufacturing. At first I`ve focused my efforts on setting up a biorefinery process that allowed to fractionate the raw lignocellulosic substrates into three potentially interesting products: lignin, cellulose nanocristals and silica. With the process, it was possible to recover simultaneously all the main fractions with high purity and reasonable yield. Later, through a modification of the biorefinery process a fourth material was prepared, a biofiller composed by lignin and silica. This material is potentially extremely interesting since it combines the desirable characteristics of both silica (state of the art filler in high performance tyres) and lignin (renewable, lightweight, with antioxidant properties). At first all the products generated through the process form the lignocellulosic substrates were tested in rubber model compounds. After the first screening of the properties in composites with natural rubber, the effort focused on lignin based materials, studying the influence of their properties on the thermal and mechanical properties of their composites with natural rubber. The work followed three main topics: identification of relationships between lignin molecular structure and the performances in the elastomeric compounds, improvement of the characteristics by means of different thechniques (fractionation, thermal processes and chemical modifications) and optimization of the lignin-silica biofiller in order to improve its reinforcing capability.

Wood artefacts undergo complex alteration and degradation during ageing, and gaining information on the chemical composition of wood in archaeological artefacts is fundamental to plan conservation strategies. In this work, an integrated analytical approach based on innovative NMR spectroscopy procedures, gel permeation chromatography and analytical pyrolysis coupled with gas chromatography/mass spectrometry (Py-GC-MS) was applied for the first time on archaeological wood from the Oseberg collection (Norway), in order to evaluate the chemical state of preservation of the wood components, without separating them. We adopted ionic liquids (ILs) as non-derivatising solvents, thus obtaining an efficient dissolution of the wood, allowing us to overcome the difficulty of dissolving wood in its native form in conventional molecular solvents. Highly substituted lignocellulosic esters were therefore obtained under mild conditions by reacting the solubilised wood with either acetyl chloride or benzoyl chloride. A phosphytilation reaction was also performed using 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholan. As a result, the functionalised wood developed an enhanced solubility in molecular solvents, thus enabling information about modifications of lignin, depolymerisation of cellulose and structure of lignin-carbohydrate complexes to be obtained by means of spectroscopic (2D-HSQC-NMR and (31)P-NMR) and chromatographic (gel permeation chromatography) techniques. Py-GC-MS was used to investigate the degradation undergone by the lignocellulosic components on the basis of their pyrolysis products, without any pre-treatment of the samples. The application of all these combined techniques enabled a comprehensive characterisation of the whole cell wall of archaeological wood and the evaluation of its state of preservation. High depletion of carbohydrates and high extent of lignin oxidation were highlighted in the alum-treated objects, whereas a good preservation state was found

An epoxidized lignin derivative was prepared directly inserting epichlorohydrin on the phenolic functionalities. The epoxidized lignin was then converted to cyclic carbonates through the coupling reaction of CO2 with the oxirane rings. Imidazolium based ionic liquids, acting as both solvents and catalysts, were successfully employed in the carbonation reaction. Moreover, the ionic liquid was reused up to three times without significant loss in activity. Finally, an exhaustive spectroscopic characterization was carried out on the epoxidized and carbonated lignins by quantitative 31P and 13C NMR analyses.

The aim of this work is to elucidate the relationship between lignin main features and its behavior in natural rubber compounds, in particular focusing on thermal stability and mechanical properties. Five lignins obtained from different sources and through different extraction processes were characterized in terms of purity, sulfur content, molecular weight distribution (GPC), and qualitative and quantitative functional group distribution (FTIR and 31P NMR). Then, the lignins were incorporated in natural rubber by two different approaches, namely coprecipitation and dry-mixing. Thermal stability and mechanical properties of lignin/natural rubber blends were investigated in both masterbatches and vulcanized compounds. The oxidation induction time (OIT) was used to determine the thermal stabilization of the lignin/NR masterbatchs, while tensile stress-strain properties of the compounds were evaluated after vulcanization. It was found that differences in the chemical and morphological characteristics of lignin influence its antioxidant and reinforcement capability. The addition of lignin to vulcanized compounds demonstrated the possibility to improve mechanical properties hypothetically through a tandem mechanism of protection and reinforcement.

An integrated biorefinery process based on acidic leaching, alkaline treatment and concentrated sulfuric acid hydrolysis was set up for the simultaneous recovery of lignin, hemicelluloses, silica, and cellulose nanocrystals (CNCs) from Arundo donax and rice husk. These fractions can serve as viable source of bio-chemicals with potential high-value applications. A chromatographic and spectroscopic characterization demonstrated that a combined acidic-alkaline treatment enhanced the degradation of lignin-carbohydrates complexes releasing lignin and hemicelluloses in higher yield and purity than the sole alkaline treatment. The remaining cellulose rich solid was bleached through a totally chlorine free process, and then hydrolyzed for cellulose nanocrystals isolation. A. donax cellulose nanocrystals were extracted and characterized for the first time in literature. Moreover, from rice husk, pure amorphous silica was obtained almost in 90% yield and 99% purity, avoiding incineration. In term of mass balance, it was possible to refine the investigated biomasses for the production of lignin, hemicelluloses, silica and CNCs in almost 40% overall yield.

The consolidation of samples of waterlogged wood was attempted using allylated lignin as cross-linker and compatibilizer in the silicone oil conservative treatment. During the curing of the composite, allylated lignin was reacted with a poly(dimethylsiloxane) hydride terminated on both the ends of the silicone chain through a hydrosilylation reaction in the presence of the Karstedt’s catalyst. Three lignin–silicone hybrids were prepared using different allyl/hydride group ratios. Preliminary wood consolidation was thus accomplished treating pieces of wood with lignin–silicone hybrids prepared in situ with silicone and allylated lignin in different concentrations in the presence of the Karstedt’s catalyst. IR and SEM-EDX analysis proved that the growth of the silicone–lignin polymer was easier within the external layers. In addition, water uptake tests and contact angle measurements were performed on consolidated wood samples to evaluate the extent of hydrophobicity.

L’introduzione di co- e ter-monomeri nella catena di polietilene, ottenuta con catalizzatori Ziegler-Natta permette di modularne le proprietà fisiche e chimiche come la temperatura di transizione vetrosa (Tg) e di incrementare le proprietà meccaniche e termiche del materiale. In particolare, i copolimeri etilene-norbornene (E-N) ottenuti per sintesi metallocenica hanno alta resistenza termica, elevata resistenza all’azione di solventi, elevate proprietà barriera ai gas e alta trasparenza ottica (I. Tritto, L. Boggioni, D.R. Ferro, Coordination Chemistry Reviews, 250, 212-241, (2006)). Copolimeri ad alto contenuto di norbornene mantengono queste ottime caratteristiche ma sviluppano una componente fragile. Per sopperire a questo svantaggio, si è deciso di esplorare una nuova strategia di sintesi, introdotta nel 2006 dalla Dow Chemical Company (D.J. Arriola, E.M. Carnahan, P.D. Hustad, R.L. Kuhlman, T.T. Wenzel, Science, 312, 714 (2006)), chiamata “Chain Shuttling polymerization” (CSP). CSP permette di ottenere copolimeri con microstruttura multiblocco in cui differenti microstrutture sono legate insieme in una sequenza alternata all’interno della stessa catena polimerica. Il sistema catalitico della CSP è composto da tre componenti fondamentali: due catalizzatori con differente affinità alle unità monomeriche e un trasferitore di catena (CTA) che scambia le catene crescenti da un centro catalitico ad un altro. A questo proposito abbiamo selezionato: i) un catalizzatore con alta affinità al norbornene, ii) un catalizzatore con bassa incorporazione di norbornene, iii) dietilzinco come agente di chain shuttling (CSA) e studiato due diversi sistemi catalitici: i) due zirconoceni con differenti leganti, per valutare l'influenza del legante sulle proprietà finali del polimero; ii) due metalloceni con diverso metallo centrale e gli stessi leganti. L'attivazione del catalizzatore è stata effettuata con dimetilanilinio tetrakis(pentafluorofenil)borato per entrambi i

The present invention relates to a tyre for vehicle wheels comprising at least one structural element comprising a crosslinked elastomeric material obtained by crosslinking a crosslinkable elastomeric compn. comprising a predispersion of natural rubber and lignin obtained by co-pptn. from latex, where said lignin has a concn. of phenolic groups higher than 2 mmol per g of lignin, and where said predispersion comprises an amt. of said lignin such as to provide, in said crosslinkable elastomeric compn., a concn. of lignin equal to or lower than about 25 phr

A sample of hardwood from the Riksapplet shipwreck (Dalaro, 1676) and a softwood sample treated with PEG found near the Vasa warship (Stockholm, 1628) wreck site were chemically characterized. The different fractions (namely extractives, lignin and holocellulose) composing the hardwood and softwood samples were isolated and compared with a sound reference sample of the same genus. Two-dimensional Heteronuclear Single Quantum Coherence, 31Phosphorous NMR and gel permeation chromatography showed no differences between the wood samples recovered from the shipwrecks and the reference samples concerning extractives, lignin and holocellulose. Moreover, innovative analyses by gel permeation chromatography of the entire derivatized wood cell wall material that allows for the detection of all substrate components namely, cellulose, hemicellulose, and lignin, particularly focusing on the presence of lignin-carbohydrate complexes, suggested that the molecular weight distributions of the waterlogged wood samples were comparable with the references confirming a good state of preservation. Maximum water content (MWC %), iron and sulfur content have also been measured and related to the result from chemical characterizations.

Lignocellulosic biomass is a natural complex composite of cellulose, hemicellulose, lignin, ashes and other soluble substances called extractives. The significant difficulties related to the separation of lignin-carbohydrates complexes are the major obstacle to overcome for lignocellulosic biomass utilization. In order to free the locked polysaccharides in cellulose, a number of lignocellulose pretreatment technologies is under intensive investigations, such as steam explosion, organosolv process, chemical treatment with acids or bases (ammonia, NaOH) and ionic liquid pretreatment. The relevance of lignocellulosic biorefinery relies not only on the recovery of carbohydrates, but also on the added value of lignin which is the second most abundant natural polymer, exceeded only by cellulose and hemicellulose. Lignin’s structure is determined by its botanical origin and the adopted isolation process. Depending on the plant source, lignins can be divided into three classes: hardwood (angiosperm), softwood (gymnosperm) and annual plant (graminaceous); on the other hand, according to the isolation process, lignins can be divided into two groups: lignin from sulfite process and sulfur free lignin. The latter is receiving increasing attentions because it offers a greater versatility than the former and it can be heat-processed avoiding the irritating odor-release commonly associated with commercial kraft lignin. In addition to cost advantages, annual renewability and huge availability are factors that could promote the use of sulfur-free lignin. Lignin’s structure contains a variety of chemical functional groups that affect its reactivity making it able to meet the needs of industry. It’s worth noting that lignin can be used for several industrial applications owing to its surface-active properties. It has also been applied as a filler in many elastomers (butadienestyrene- butadiene, isoprene-styrene-butadiene; styrenebutadiene) or in natural rubber. Moreover, lignin has sh

The effect of raw material and pretreatment procedure on the structure and properties of industrial lignins was evaluated by detailed chemical and physical characterization. The application potential of studied lignins was considered based on those. Hydrolysis lignin and steam exploded lignins had clearly distinct characteristics compared to the spent liquor lignins; higher molar mass, significantly higher amount of native aryl ether linkages and thereby low phenol content. The hydrolysis lignin also contained significant amount of carbohydrate and protein residues, which may affect the applicability. For resin applications, the kraft lignins seem most reactive in respect of high phenol content. The high molar mass of hydrolysis lignin and steam exploded lignins could be beneficial for dispersants and composites

The conversion of lignin into value-added products is traditionally hampered by its stochastic structure and its complex reactivity. In this work, for the first time, is reported the allylation reaction and the aromatic Claisen rearrangement of the allyl group on lignin as chemical modifications aimed at the development of new lignin-based materials and the improvement of its compatibility and ease of processing. In particular, the Claisen rearrangement of lignin was foreseen as a valuable approach to release phenolic groups in an already chemically modified lignin, giving additional reactive sites for further transformation. These reactions were carried out on a purely guaiacylic lignin (TMP), taken as reference material for its simplicity, and on a more structurally complex herbaceous lignin (P1000®). The Claisen rearrangement of the allylic chain was successfully achieved by treatment in dimethylformamide at reflux temperature for 15 hours. Finally, a screening of the antioxidant activity of reference, allylated, and Claisen rearranged lignins was carried out. Rearranged lignins exhibited satisfying antioxidant activities if compared to the reference ones.

Lignocellulosic materials, biomass not destinated for human and/or animal consumption, are the base of the second generation bioethanol production plants. These materials are composed primarily by cellulose, hemicellulose and lignin. After hydrolysis, the sugars from the polysaccharides can be converted into ethanol by fermentation, and the residues of the process are composed mainly of lignin. Considering the growing interest in this type of plants, large amounts of lignin will be available in the future. Currently, the lignin is a by-little used. Obvious economic and environmental reasons require to enhance this product

Lignins from a steam explosion process in crude and purified forms and modified sulphur-free commercial lignin (Protobind 3000®) were characterised to establish their chemical compositions. Then, the lignins were tested again after treatment with hexamethylenetetramine (HMT). The resulting products were used to make rubber composites, and their mechanical properties were compared to rubber composites made with carbon black to test the possibility of using HMT-treated lignins as a partial replacement for carbon black in the production of rubber composites. In the crude lignin, a significant amount of impurities were detected, such as ash and residual polysaccharides, and these substances interfered in filler-elastomer interactions. The purified lignin maintained a high content of strongly polarised hydroxyl groups that interfered with the interaction of the filler and elastomer, resulting in low performance. Improvements in the mechanical properties were observed using Protobind 3000® lignin or purified lignin with HMT added during mixing with the rubber. Finally, the mixing of HMT-treated lignin with elastomers resulted in composites with higher reinforcement abilities compared to previously described rubber composites. However, in all samples, a poor and unsatisfactory dispersion of lignin in the polymeric matrix was observed. This is likely due to the incompatibility of lignin with the hydrophobic rubber, resulting in lower performances compared to the carbon black.

A series of experimental tests has been conducted to investigate the efficiency and the by-product generation of high dose ozonation (10 to 60 mg O3 L-1) for complete colour removal from a treated effluent with an important component of textile dyeing wastewater. The effluent is discharged into an effluent-dominated stream where no dilution takes place, and thus, the quality requirement for the effluents is particularly strict. Three contact times were adopted: 30, 60 and 90 min. Colour was measured as absorbance at 426, 558 and 660 nm wavelengths. The experimental work showed that at 50 mg L-1 colour removal was complete and at 60 mg O3 L-1 the final aldehyde concentration ranged between 0.72 and 1.02 mg L-1. Glyoxal and methylglyoxal concentrations were directly related to colour removal, whereas formaldehyde, acetaldehyde, acetone and acrolein were not. Thus, the extent of colour removal can be used to predict the increase in glyoxal and methylglyoxal concentrations. As colour removal can be assessed by a simple absorbance measurement, in contrast to the analysis of specific carbonyl compounds, which is much longer and complex, the possibility of using colour removal as an indicator for predicting the toxic potential of ozone by-products for textile effluents is of great value

The present invention relates to a tyre for vehicle wheels comprising at least one structural element comprising a crosslinked elastomeric material obtained by crosslinking a crosslinkable elastomeric compn. comprising (a) at least one dienic elastomeric polymer; (b) at least one carbon black reinforcing filler; and (c) at least one functionalized lignin selected from the group consisting of esterified lignin and etherified and esterified lignin

We describe a new use of switchable-polarity solvents for the simultaneous derivatization and extraction of triacylglycerols from vegetable oils before gas-chromatographic analysis. Different equimolecular mixtures of the commercially available amidine 1,8-diazabicyclo[5.4.0]undec-7-ene and n-alkyl alcohols were tested. Triolein was used as a model compound. Very good results were achieved by using butanol (recovery of butyl oleate was 89 ± 4%). The procedure was applied for the characterization of the fatty acid profile of different vegetable oils. No statistically significant differences from the results obtained with the application of two traditional methods were evidenced. Moreover, the use of switchable-polarity solvents showed many advantages: owing to the basicity of the amidines, no catalyst was required; the transterification reaction was conducted under mild conditions, one step and in situ; no particular matrix interferences were evidenced; the solvent was recovered

The increasing use of new generation plastics has been accompanied by the development of standard methods for studying their biodegradability. Generally, test methods are based on the measurement of CO2 production, i.e. the mineralization degree of the tested materials. However, in order to describe the biodegradation process, the determination of the residual amount of tested material which remains in the environment and its chemical characterization can be very important. In this study, the biodegradation in soil of a model polyester (poly(butylene sebacate)) was monitored. Gel Permeation Chromatography and Nuclear Magnetic Resonance (31P-NMR and 1H-NMR) were used in order to obtain information about the polyester structure and the possible by-products that can be found in soil during and at the end of the incubation. The polyester mineralization (i.e. the CO2 production) was tested according to ASTM 5988 standard method for 245 days. When the polyester mineralization was about 21% and 37% (after 78 and 140 days of incubation) and at the end of the process (63% of mineralization, 100% if compared to the cellulose used as reference material), the soil was extracted with chloroform (solvent of the tested substance) and the extracts were analyzed using GPC and NMR acquisitions. The analytical acquisitions showed high molecular weight polyester in soil during the incubation (78 and 140 days): the polyester concentration decreased but its structure remained almost the same with a slow decreasing in molecular weight. At the end of the test (245 days) no film of the polyester could be extracted from the soil: NMR acquisitions and GPC analyses of the extracts suggested a strong degraded structure of the residual polyester. Even if at the end of the process only 63% of carbon had been lost by mineralization, the whole of the added polyester seems to have disappeared after about eight months of incubation, suggesting substantial biomass formation

The recalcitrance of lignocelluloses toward enzymatic hydrolysis necessitates pretreatments. Ionic liquid pretreatment with 1-allyl-3-methylimidazolium chloride ([amin]Cl) was applied to risk husk and cellulose-containing fractions were recovered from the ionic liquid solutions by acidic, alkaline, and alkaline-acidic regeneration respectively. Enzymatic hydrolysis of the recovered materials was carried out and results demonstrated that: (i) acidic regeneration was not substantial to ensure enhanced enzymatic digestibility; (ii) alkaline regeneration increased the enzymatic hydrolysis; (iii) alkaline-acidic regeneration led to an almost complete hydrolysis of the carbohydrate fraction. The obtained results were rationalized by means of chromatographic analyses of soluble fractions collected after the different regeneration processes: the removal of hemicellulose, which increased going from the acidic to the alkaline-acidic regeneration, seemed to play a crucial role in enhancing the rice husk saccharification.

The PhD project is inserted within the broad field of lignocellulose chemical characterization and comprehensive utilization, as promoted by the biorefinery approach. Lignocellulose is an extremely structurated natural material made up of three main biopolymers: cellulose, hemicellulose, and lignin. Cellulose consists of linear chains of beta(1-4) linked D-glucopyranose units which, when found in cell wall, is difficult to break down into glucose because of its extensive inter- and intra-molecular H-bonded network and highly organized crystalline structure. Hemicellulose is a carbohydrate heteropolymer composed of several different sugars including five-carbon and six-carbon which is easily broken down into its building blocks. Lignin is a complex and irregular polymer network, composed of randomly cross-linked phenylpropanoid units, and acts as a glue holding cellulose and hemicellulose together. The biorefinery concept is analogous to today’s petroleum refinery that produces multiple fuels, power and chemical products from petroleum. Biorefinery systems generally work by processing a bio-based feedstock input to create fuel, chemicals, feed or power/heat as an output. Lignocellulose biorefinery generally includes three fundamental steps: first, a pretreatment to fractionate the recalcitrant lignocellulose structure; secondly, an enzymatic hydrolysis of the isolated cellulose moiety to obtain fermentable sugars; and third, the fermentation, to produce cellulosic ethanol or other bio-based chemicals. Because of the resistant structure of crystalline cellulose and natural composite structures of lignocellulosics, efficient pretreatment technologies are needed prior to the enzymatic hydrolysis. The PhD project find its common thread in the development and application of an integrated analysis protocol that encloses different chromatographic and spectroscopic techniques, and the utilization of innovative solvent media (i.e., ionic liquids) for the functionalization and

Lipids are a broad group of naturally occurring molecules, which includes fats, oils, waxes, sterols, terpenes, fat-soluble vitamins, monoglycerides, diglycerides, phospholipids and others. Lipids have been widely used in human history and they are often present in archaeological finds. In particular, in the field of medicine and cosmetics, lipids have been employed as base in the preparation of unguents, salves and balms. The characterization of these products and their degradation products induced by ageing is important for an understanding of the ancient pharmaceutical techniques and to assess the state of conservation. 1H-NMR and, for the first time, 31P-NMR spectroscopy have been applied to the characterization of such compounds. By derivatization of the samples with 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane, it is possible to recognize, quantify and evaluate the degradation degree of lipids in archaeological unguent samples. With this new approach, lipids have been recognized in 17th-century archaeological ointments from the Aboca Museum. Moreover, severe hydrolysis and oxidation markers have been detected

Ozonation of N-aryl-cyclic amines in organic solvents gave N-aryl-lactams regioselectively. In particular, 4-(4-aminophenyl)-morpolin-3-one, a key intermediate in the preparation of factor Xa inhibitors, was obtained in fair yields. The method represents an alternative approach for the lactamization of tertiary N-arylic substrates and is based on a “metal-free” introduction of the carbonyl function into the heterocyclic ring.

Rice husk lignin was isolated by means of acidolytic (AL) or alkaline enzymatic (AEL) extraction method. Biocomposites of poly(3-hydroxybutyrate) (PHB) and acetylated lignin were prepared by casting from chloroform solution. The morphological, structural and thermal characteristics of the biocomposites were extensively studied. The ligno-derivatives features, i.e. purity, chemical structure and molecular weight, influenced the thermal properties of the PHB-based biocomposites. The AL sample evidenced a marked interference on the crystallization behaviour and thermo-oxidative degradation of the PHB. The decrease of PHB crystallization rate and the increase of thermal stability were observed as a function of the lignin amount in PHB-AL biocomposite series.