Synthesis and characterization of fluorinated compounds for industrial applications

The presence of fluorine atoms in the structure of an organic molecule alters in an extraordinary way its physico-chemical properties and the countless applications of organo-fluorine compounds are a strong testimony of it. The unique properties of fluorinated surfaces (low surface tension, dielectric constant, friction coefficient) derive from the particular features of the C-F bond (Chapter 1). Thanks to their exceptionally low intermolecular interactions, fluorinated compounds produce surfaces with very low interfacial energies which are hardly wet by aqueous and organic liquids, have anti-adhesive properties and low friction coefficients. Thanks to these unique properties fluoro-polymers play an important role in various fields of modern industry. Fluorinated thermoplastic polymers endowed with high thermal stability, low dielectric constants, excellent chemical resistance, very low surface tensions have now become commonly used both in the industrial practice and in everyday life applications (non-stick cookware, waterproof and breathable fabrics, optical fibers, to name a few). In 2006 the EPA (Environmental Protection Agency) demonstrated the bio-accumulative effects of several perfluoro organic compounds with long perfluoro alkyl chain (and their derivatives). This environmental aspect led to the progressive banning of all long chain fluorotelomers compounds within 2015 (Chapter 2). Many of these compounds are currently comprised in the candidate list for SHVC (substances of very high concern) enclosed in the CLP Regulation. As a consequence of these decisions companies involved in the manufacture and marketing of fluoro-compounds for surface treatment are replacing long perfluorinated alkyl compounds with shorter ones. The shortening of the chain length of the fluorinated moiety has posed challenging technological issues because of the dramatic loss of performances. The goal of researchers is to find new molecular solutions able to maintain the same performances of “old” long chain molecules with shorter compounds. In this work the study of alternative fluorinated polymers, obtained by controlled radical polymerization techniques (Chapter 3) were investigated. In particular, the synthesis of fluoroalkyl styrene monomer with short fluorinated chain was carried out (Chapter 4) and the optimization of the synthesis of its precursor, 4’-nonafluorobutyl acetophenone, was also studied. The fluoroalkyl styrene monomer was polymerized by conventional radical polymerization and controlled radical polymerization (Chapter 5). Further, the telomerization of polyvinylidene fluoride in presence of 1-iodoperfluorobutane and trifluoromethyl iodide as chain transfer agents were investigated. The telomers synthesized were characterized by NMR analyses and the structure of the telomers chains were determined (Chapter 6)

Synthesis and characterization of fluorinated compounds for industrial applications

The presence of fluorine atoms in the structure of an organic molecule alters in an extraordinary way its physico-chemical properties and the countless applications of organo-fluorine compounds are a strong testimony of it. The unique properties of fluorinated surfaces (low surface tension, dielectric constant, friction coefficient) derive from the particular features of the C-F bond (Chapter 1). Thanks to their exceptionally low intermolecular interactions, fluorinated compounds produce surfaces with very low interfacial energies which are hardly wet by aqueous and organic liquids, have anti-adhesive properties and low friction coefficients. Thanks to these unique properties fluoro-polymers play an important role in various fields of modern industry. Fluorinated thermoplastic polymers endowed with high thermal stability, low dielectric constants, excellent chemical resistance, very low surface tensions have now become commonly used both in the industrial practice and in everyday life applications (non-stick cookware, waterproof and breathable fabrics, optical fibers, to name a few). In 2006 the EPA (Environmental Protection Agency) demonstrated the bio-accumulative effects of several perfluoro organic compounds with long perfluoro alkyl chain (and their derivatives). This environmental aspect led to the progressive banning of all long chain fluorotelomers compounds within 2015 (Chapter 2). Many of these compounds are currently comprised in the candidate list for SHVC (substances of very high concern) enclosed in the CLP Regulation. As a consequence of these decisions companies involved in the manufacture and marketing of fluoro-compounds for surface treatment are replacing long perfluorinated alkyl compounds with shorter ones. The shortening of the chain length of the fluorinated moiety has posed challenging technological issues because of the dramatic loss of performances. The goal of researchers is to find new molecular solutions able to maintain the same performances of “old” long chain molecules with shorter compounds. In this work the study of alternative fluorinated polymers, obtained by controlled radical polymerization techniques (Chapter 3) were investigated. In particular, the synthesis of fluoroalkyl styrene monomer with short fluorinated chain was carried out (Chapter 4) and the optimization of the synthesis of its precursor, 4’-nonafluorobutyl acetophenone, was also studied. The fluoroalkyl styrene monomer was polymerized by conventional radical polymerization and controlled radical polymerization (Chapter 5). Further, the telomerization of polyvinylidene fluoride in presence of 1-iodoperfluorobutane and trifluoromethyl iodide as chain transfer agents were investigated. The telomers synthesized were characterized by NMR analyses and the structure of the telomers chains were determined (Chapter 6).La presenza di atomi di fluoro all’interno di una molecola organica è in grado di alterarne le proprietà chimico-fisiche in modo significativo e le innumerevoli applicazioni dei composti fluorurati ne sono la prova. Le proprietà superficiali dei composti fluorurati sono attribuibili alle particolari caratteristiche del legame C-F. (Capitolo 1). Le basse interazioni intermolecolari proprie dei composti fluorurati conferiscono alle superfici proprietà chimico-fisiche uniche: difficile bagnabilità da parte di liquidi acquosi ed organici, spiccate proprietà anti-adesive e basso coefficiente d’attrito. I composti fluorurati giocano pertanto un ruolo importante in svariati ambiti dell’industria moderna. I polimeri termoplastici fluorurati sono dotati di alta stabilità termica, bassa costante dielettrica, eccellente resistenza chimica, bassissima tensione superficiale. Nel 2006 l’EPA (Environmental Protection Agency) dimostrò gli effetti di bio-accumulo di diversi composti perfluoroorganici dotati di una lunga catena perfluoroalchilica (e relativi derivati). Gli aspetti ambientali hanno portato alla progressiva dismissione di tutte le molecole fluorocarburiche a catena lunga entro il 2015 (capitolo 2). Alcuni di questi composti sono già presenti nella candidate list per le SVHC (substances of very high concern) del Regolamento CLP. In conseguenza di queste decisioni le aziende coinvolte nella produzione e commercializzazione di prodotti foluorurati hanno cercato di adeguarsi rimpiazzando i prodotti fluorurati a lunga catena fluorocarburica con prodotti a catena corta. L’accorciamento della catena fluorocarburica ha posto un problema tecnologico legato alla perdita delle performance dei nuovi composti fluorurati. Lo scopo dei ricercatori è quello di sintetizzare nuove molecole, in grado di mantenere le stesse performance dei vecchi composti a catena lunga e che non ne presentino più le caratteristiche di bioaccumulo e tossicità. In questo lavoro di ricerca si è studiata un’alternativa ai composti fluorurati a lunga catena per applicazioni superficiali utilizzando tecniche di polimerizzazione radicalica controllata di monomeri a corta catena fluorurata (Capitolo 3). In particolare, si è studiata la sintesi di un monomero fluoroalchil stirenico a catena fluorocarburica corta, ottimizzando la sintesi del suo precursore, il 4’-nonafluorobutil acetofenone (Capitolo 4). Il monomero fluoroalchil stirenico è stato quindi polimerizzato attraverso una reazione di polimerizzazione radicalica convenzionale e controllata (Capitolo 5). Infine, si è studiata la telomerizzazione del vinilidene fluoruro in presenza di 1-iodoperfluorobutano e trifluorometilioduro come chain transfer agents. I telomeri sintetizzati sono stati caratterizzati attraverso misure di spettroscopia NMR, le quali hanno permesso di determinare la struttura delle catene (Capitolo 6)

Synthesis and Characterization of Partially Fluorinated Ethers

A series of partially fluorinated ethers PFE-m,n with general formula F(CF2)(m)CH(2)CH(2)O(CH(2))(n)H(m = 4, 6, 8 and n = 2, 3, 5, 8, 14, 18, 21) has been synthesized and characterized. The present work aimed to investigate the synthesis of PFE-m,n and evaluate some of their fundamental physico-chemical properties such as: specific gravity, refractive index, viscosity, solid-solid transitions, solubility and amphiphile surface activity in a variety of solvents. Further, a comparison between PFE-m,n and the well known semifluorinated n-alkanes F(CF2)(m)-(CH(2))(n)H (FHm, n) with the same value of the m/n ratio have been reported

Optimization of the Synthesis of 4-nonafluorobutylacetophenone by metal Catalysed Cross-Coupling Reactions

In this work, the synthesis of 4'-nonafluorobutylacetophenone (1) by the reaction between perfluorobutyl iodide and 4'-bromoacetophenone in the presence of N,N dimethylformamide (or dimethyl sulfoxide) as the solvent, was carried out with different transition metals as Cu0, Cu(I), Cu(II), Fe0, Fe(II), and Fe(III). Investigation on the effects of ligands, solvents, temperature and metal catalyst on the yields was optimized[5], with the purpose to find out the best conditions for the synthesis of the product

Controlled radical polymerization vs conventional radical polymerization: differences in surface properties of 4 -nonafluorobutyl styrene polymers

4\u2019-Nonafluorobutyl styrene was synthesized and polymerized by conventional and controlled radical polymerization (CRP) based on iodine transfer polymerization (ITP) technique. The fluorinated monomer was prepared from Ullmann coupling between 1-iodoperfluorobutane and 4\u2019-nonafluorobutyl acetophenone followed by a reduction and a dehydration in overall 50% yield. The radical polymerization of 4\u2019 - nonafluorobutyl styrene was initiated by AIBN and controlled by 1-iodoperfluorohexane in 84% monomer conversion and in 50% yield. The benefits of ITP of 4\u2019-nonafluorobutylstyrene featured (i) a fast monomer conversion, monitored by 1H and 19F NMR in the presence of 1,2-dichloroethane as the internal standard, (ii) the evolution of the ln([M]0/[M]) versus time that evidenced a linear behavior

Optimization of the synthesis of 4-nonafluorobutylacetophenone by metal catalysed cross-coupling reation

The synthesis of 4\u2032-nonafluorobutylacetophenone by metal-assisted cross-coupling reaction of 1-iodo-perfluorobutane and 4\u2032-bromoacetophenone is presented. The effect of metal (iron, copper) metal salt (copper(I) bromide, copper(II) chloride), ligand (2,2\u2032-bipyridine, N,N,N\u2032,N\u2033,N\u2034,N\u2034-hexamethyltriethylenetetramine, N,N,N\u2032,N\u2033,N\u2033-pentamethyldiethylenetriamine), and solvent (N,N-dimethylformamide, dimethylsulfoxide) was studied in order to elucidate their role in the optimization of the reaction conditions. The best conditions were found for the reaction carried out in presence of copper as catalyst, 2,2-bipyridine as ligand and in presence of N,N-dimethylformamide as solvent that led to 73% yield of the desired product (for a quantitative conversion of both 1-iodo-perfluorobutane and 4\u2032-bromoacetophenone). The resulting product was characterized by nuclear magnetic resonance, IR, and mass spectroscopy

Optimal inductor design for nanofluid heating characterisation

Purpose-Magnetic fluid hyperthermia experiment requires a uniform magnetic field in order to control the heating rate of a magnetic nanoparticle fluid for laboratory tests. The automated optimal design of a real-life device able to generate a uniform magnetic field suitable to heat cells in a Petri dish is presented. The paper aims to discuss these issues. Design/methodology/approach-The inductor for tests has been designed using finite element analysis and evolutionary computing coupled to design of experiments technique in order to take into account sensitivity of solutions. Findings-The geometry of the inductor has been designed and a laboratory prototype has been built. Results of preliminary tests, using a previously synthesized and characterized magneto fluid, are presented. Originality/value-Design of experiment approach combined with evolutionary computing has been used to compute the solution sensitivity and approximate a 3D Pareto front. The designed inductor has been tested in an experimental set-up

Physical characterization of high rate heating magnetic nanoparticles for MFH

Flower-shaped magnetic nanoparticle powders, synthetized by thermal decomposition, dispersible in water have been submitted to a physical characterization to evaluate their magnetic behavior in view of their use Magnetic Fluid Hyperthermia treatments