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The synthesis and characterization of phosphonium and arsonium salts having anthraquinone and anthracene moiety was carried out by reacting equimolar amounts of halomethyl anthracene or anthraquinone with triphenylphosphine or triphenyl arsine in toluene solvent. The halide counter (Cl or Br) ion was exchanged with hexafluoro antimonate (SbF6-) which proved to be a useful photoinitiator for polymerizing cyclohexene oxide, styrene, p-methyl styrene, and N-vinylcarbazole. The experimental results demonstrate the effects of salt, monomer structures, and the photolysis time on the rate of polymerization and the number average molecular weight of the obtained polymer. These salts are easy to handle, nonhygroscopic under laboratory conditions, and they have good solubility in halogenated solvents such as dichloromethane and chloroform.

Taking advantage of the unique properties of two-component flavo-monooxygenases and the ability of [Cp*Ir(bpy-OMe)H]+ to transfer hydrides to reduce flavins, we extended the scope of the pH- and oxygen-robust iridium(iii)-complex to drive the enzymatic reaction of a FMN-dependent Baeyer-Villiger monooxygenase and a FAD-dependent styrene monooxygenase (respectively FPMO Group C and E), using formic acid as H-donor for NADH recycling.

The introduction of phosphine oxide as anchoring groups in the hydrophobic core of amphiphilic star-block copolymers leads to greatly improved confinement of rhodium nanoparticles (RhNPs) inside the nanoreactors with a benefit in aqueous biphasic catalysis. The copolymers are specially designed core-crosslinked micelles (CCMs) forming a stable latex by reversible addition-fragmentation chain-transfer (RAFT) polymerization. They possess a hydrophilic shell made of polycationic 4-vinyl-N-methylpyridinium iodide P(4VPMe+I−) chains, a triphenylphosphine oxide (TPPO)-functionalized polystyrene core and are crosslinked at the inner end of the polystyrene chains by diethylene glycol dimethacrylate (DEGDMA) (TPPO@CCM-C). Ex-situ synthesized RhNPs readily cross the hydrophilic shell and remain anchored within the CCM nanoreactor cores. The RhNP-loaded TPPO@CCM-C latex was applied as catalyst in the hydrogenation of styrene under mild conditions with complete selectivity towards ethylbenzene and average turnover frequency (TOF) up to 12000 h−1, corresponding to a corrected TOF (cTOF) up to 16800 h−1 based on only surface atoms of the RhNPs. Moreover, the catalytic phase proved recyclable after product extraction with diethyl ether, demonstrating efficient retention of the RhNPs by the core TPPO ligands. Although the activity decreased after the first catalytic run, it converged to a stable average TOF of ca. ∼1025 h−1 (cTOF of ca. ∼1440 h−1), which was similar to that of an extensively pre-washed RhNP-TPPO@CCM-C latex. This phenomenon is attributed to a promoter effect of adsorbed ligands, which were used as stabilizer for the RhNPs synthesis and were gradually removed during the work-up washings between recycles.

A series of ruthenium nanoparticles (RuNPs) were synthesized by the organometallic approach in different functionalized imidazolium ionic liquids (FILs). Transmission electron microscopy (TEM) showed well-dispersed and narrow-sized RuNPs ranging from 1.3 to 2.2 nm, depending on the IL functionalization. Thermal gravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS) allowed the interaction between the RuNPs and the ILs to be studied. The RuNPs stabilized by methoxy-based FILs (MEM and MME) displayed a good balance between catalytic activity and stability when evaluated in the hydrogenation of styrene (S) under mild reaction conditions. Moreover, the catalysts showed total selectivity towards ethylbenzene (EB) under milder reaction conditions (5 bar, 30 °C) than reported in the literature for other RuNP catalysts.

Intriguing phase morphology was formed through self-assembly of polylactide-polystyrene (PLA-co-PS) graft copolymers blended with polylactide (PLA). PLA-co-PS graft copolymers were synthesized by exploiting a styrene-functionalized 1,3-Dioxolan-4-one (StyDOX) monomer through a two-step procedure and their structure was confirmed. Different amounts of PLA-co-PS and commercial PLA were solution cast to blend films. Etching of amorphous PLA revealed the presence of spherical micrometer sized domains dispersed within the films, arising from the self-assembly behavior of PLA-co-PS caused by the immiscibility of PS-grafts in the PLA matrix. EDS and IR imaging analyses further revealed that these microspheres were characterized by a PS-rich core opposed to the PLA-rich outer shell, which is expected to be miscible and able to form favorable interactions with the PLA matrix. PLA/PS blends were also prepared with different loadings of PLA-co-PS. The ability of PLA-co-PS to compatibilize the two phases was assessed through rheological analyses. Finally, the possibility to chemically recycle the copolymer was evaluated., QC 20230612

Cellulose nanofibers (CNFs) are bio-sourced nanomaterials, which, after proper chemical modification, exhibit a unique ability to disperse carbon-rich micro- and nanomaterials and can be used in the design of mechanically strong functional nanocomposites. When used in the preparation of graphite anodes for Li-ion batteries, they have the potential to outperform conventional binders such as carboxymethyl cellulose (CMC) and styrene-butadiene rubber (SBR) both electrochemically and mechanically. In this study, cellulose-rich fibers were subjected to three different chemical modifications (including carbonyl-, carboxyl-, and aldehyde-functionalization) to facilitate their fibrillation into CNFs during the preparation of aqueous slurries of graphite and carbon black. Using these binders, graphite anodes were prepared through conventional blade coating. Compared to CMC/SBR reference anodes, all anodes prepared with modified cellulosic fibers as binders performed better in the galvanostatic cycling experiments and in the mechanical cohesion tests they were subjected to. Among them, the aldehyde- and carboxyl-rich fibers performed the best and resulted in a 10% increase in specific capacity with a simultaneous two- and three-fold increase of the electrode material's stress-at-failure and strain-at-break, respectively. In-depth characterizations attributed these results to the distinctive nanostructure and surface chemistry of the composites formed between graphite and these fiber-based binders., QC 20230515

The catalytic performance of SWCNT was notably improved in the oxidative dehydrogenation of ethylbenzene (EB) to styrene (ST) upon a double-function purification in one step of the raw SWCNT. This consists of lowering the MeOx concentration and generating surface C=O groups after processing it in nitric acid at controlled conditions, while preserving the structure. The textural improvement was ascribed to the cutting of the tubes/bundles by oxidation and to MeOx removal itself (dilution effect). Both EB conversion and ST selectivity increased with a parallel lowering of the undesired COx selectivity. The conversion was interpreted by the enhancement of the intrinsic properties (i.e., more surface ketonic groups) but also to the higher load of SWCNT in the bed upon purification; both factors contribute to a higher number of active sites (C=O) in the bed for styrene formation. The most purified catalyst underperformed in conversion once the purification altered the SWCNT structure notably. Thus, preserving the structure is an important condition to achieve high conversion and yield. The better selectivity was explained in two ways; more styrene-forming sites (C=O) or less COx-forming sites (uncoated MeOx) in the bed, or both. The styrene yield per catalyst volume was improved by an average of ca. 240 % in comparison to the non-purified SWCNT. Deactivation is critical in maximizing the purification effect on the intrinsic and volumetric yields. In practical terms, the purification method proved to enhance the reaction; the selectivity towards the unwanted COx was significantly lowered with a gain towards styrene, achieving comparable selectivity values as in the conventional process, but operated at much lower temperature.

A molecular [Ru(bda)]-type (bda = 2,2’-bipyridine-6,6’-dicarboxylate) water oxidation catalyst with 4-vinylpyridine as the axial ligand (Complex 1) was immobilized or co-immobilized with 1-(trifluoromethyl)-4-vinylbenzene (3F) or styrene (St) blocking units on the surface of glassy carbon (GC) electrodes by electrochemical polymerization, in order to prepare the corresponding poly-1@GC, poly-1+P3F@GC, and poly-1+PSt@GC functional electrodes. Kinetic measurements of the electrode surface reaction revealed that [Ru(bda)] triggers the O–O bond formation via (1) the radical coupling interaction between the two metallo-oxyl radicals (I2M) in the homo-coupling polymer (poly-1), and (2) the water nucleophilic attack (WNA) pathway in poly-1+P3F and poly-1+PSt copolymers. The comparison of the three electrodes revealed that the second coordination sphere of the water oxidation catalysts plays vital roles in stabilizing their reaction intermediates, tuning the O–O bond formation pathways and improving the water oxidation reaction kinetics without changing the first coordination structures., QC 20201123

Formou literární rešerše byly vybrány možné přípravy -substituovaných -nitrostyrenů. Bylo vybráno 5 metod, které byly testovány při přípravě -methyl--nitrostyrenu. Metody přípravy této látky Henryho reakcí se nepodařilo replikovat. Z metod příprav -substituovaných -nitrostyrenů pomocí nitrace methylstyrenu byla vybrána nitrace pomocí dusitanu sodného za katalýzy dusičnanem amonno-ceričitým s výtěžkem 54 %. Byl identifikován problém nitrač-ních reakcí - vznik isomerního produktu (3-nitroprop-1-en-2-yl)benzenu, který se velmi obtíž-ně odstraňuje pomocí sloupcové chromatografie. Dále byla vyvinuta snaha vybranou metodou připravit -methyl--nitro-(4-nitrostyren) s výtěžkem 49 % a -methyl--nitro-(4-methoxystyren), který se nepodařilo izolovat., In available literature methods of syntheses of -substituted -nitrostyrenes were selected, 5 of them were tested by synthesising -methyl--nitrostyrene. Methods using the Henry reacti-on could not be replicated. From methods of syntheses of -substituted -nitrostyrenes by nitration of methylstyrene was selected procedure using sodium nitrite and ammonium ceri-um(IV) nitrate with 54 % yield. An issue with nitration reactions was indentified - forming of isomer product (3-nitroprop-1-en-2-yl)benzene, which is difficult to separate with column chromatography. Afterwards by using the selected method -methyl--nitro-(4-nitrostyrene), with 49% yield, and -methyl--nitro-(4-methoxystyrene), which could not be isolated, were prepared., Fakulta chemicko-technologická, Proč se nepodařilo reprodukovat Henryho reakci acetofenonu? Pozorovali jste vznik iminu? K čemu se mohou nitrostyreny použít? Prováděl jste osobně analýzu produktů a vyhodnocení analýz? Dotazy byly uspokojivě zodpovězeny., Dokončená práce s úspěšnou obhajobou

In this work, the potential of a microwave (MW)induced atmospheric pressure plasma jet (APPJ) in film deposition of styrene and methyl methacrylate (MMA) precursors is investigated. Plasma properties during the deposition and resultant coating characteristics are studied. Optical emission spectroscopy (OES) results indicate a higher degree of monomer dissociation in the APPJ with increasing power and a carrier gas flow rate of up to 250 standard cubic centimeters per minute (sccm). Computational fluid dynamic (CFD) simulations demonstrate nonuniform monomer distribution near the substrate and the dependency of the deposition area on the monomercontaining gas flow rate. A nonhomogeneous surface morphology and topography of the deposited coatings is also observed using atomic force microscopy (AFM) and SEM. Coating chemical analysis and wettability are studied by XPS and water contact angle (WCA), respectively. A lower monomer flow rate was found to result in a higher C–O/C–C ratio and a higher wettability of the deposited coatings., V této práci je zkoumán potenciál využití mikrovlnně indukovaného plazmového jetu generovaného za atmosférického tlaku (APPJ) při depozici tenkých filmů z prekurzorů styrenu a metyl-metakrylátu (MMA). Studovány jsou vlastnosti plazmatu během depozice a charakterizace výsledných vrstev. Výsledky z optické emisní spektrometrie (OES) ukazují na vysoký stupeň disociace monomeru v APPJ s rostoucím výkonem a při průtoku nosného plynu do 250 sccm. Simulace pomocí metody CFD ukázala na nejednotnou distribuci monomeru v blízkosti substrátu a závislost oblasti depozice na průtoku plynu obsahujícího monomer. Nehomogenní morfologie a topografie povrchu deponované vrstvy byla také pozorována pomocí mikroskopie atomárních sil (AFM) a SEM. Chemická analýza vrstvy a její smáčivost byly studovány pomocí XPS, respektive měření kontaktního úhlu vody (WCA). Bylo zjištěno, že nižší průtok monomeru vede k vyššímu poměru C–O/C–C a vyšší smáčivosti deponované vrstvy.

Carbon dioxide (CO2) is an attractive one-carbon (C1) building block in terms of sustainability and abundance. However, its low reactivity limits applications in organic synthesis as typically high-energy reagents are required to drive transformations. Here, we present a redox-neutral C-H carboxylation of arenes and styrenes using a photocatalytic approach. Upon blue-light excitation, the anthrolate anion photocatalyst is able to reduce many aromatic compounds to their corresponding radical anions, which react with CO2 to afford carboxylic acids. High-throughput screening and computational analysis suggest that a correct balance between electron affinity and nucleophilicity of substrates is essential. This novel methodology enables the carboxylation of numerous aromatic compounds, including many that are not tolerated in classical carboxylation chemistry. Over 50 examples of C-H functionalizations using CO2 or ketones illustrate a broad applicability. The method opens new opportunities for the valorization of common arenes and may find application in late-stage C-H carboxylation.

This study aims to compare the resistance against subterranean termites of wood–polymer composites produced by in situ polymerization. The biological tests were carried out by choice and no-choice feeding tests. Poly (furfuryl alcohol), poly(styrene) and poly (methyl methacrylate) were studied here. They were impregnated into a Brazilian fast-growing pine wood using a vacuum:pressure method and then cured under simple heating. These treatments were evaluated using chemical (by infrared spectroscopy) and morphological (by scanning electron microscopy) analyses. The termite attack was evaluated by mass loss determination and photography. In general, all the treatments were effective in protecting the fast-growing pine wood. Results obtained by no-choice tests indicated that the treatment solution with 75% of furfuryl alcohol was less effective than the others, which indicates that both choice and no-choice tests may be important in a comprehensive study on the termites resistance of solid woods.

A series of CMK-3-like carbon replicas was synthesized by precipitation polycondensation of furfuryl alcohol in an aqueous slurry of SBA-15 at a polymer/SiO2 mass ratio of 0.50–2.00. Changes in textural and structural parameters of SBA-15 after polymer deposition were studied by N2 adsorption and X-ray diffraction. Morphology of the replicas was investigated by transmission electron microscopy, while their surface composition was determined by temperature-programmed desorption and X-ray photoelectron spectroscopy. The mechanism of deposition of poly(furfuryl alcohol) (PFA) onto silica surface was elucidated. It was found that PFA accumulates in SBA-15 pores randomly; certain channels are completely filled, while others remain partially empty. The incomplete filling of mesopores results in “pseudo-CMK-3” structures featuring the bimodal porosity (the typical mesopores of CMK-3 are accompanied by broader ones formed by the coalescence of adjacent partially hollow pores). The total filling of pores with PFA leads to the formation of good-quality CMK-3. The carbon replicas exhibited the presence of abundant amounts of superficial oxygen-containing moieties. These entities are responsible for high activity of the materials in the oxidative dehydrogenation (ODH) of ethylbenzene, bringing evidence supporting the mechanism of active coke, considered as governing the catalytic performance of carbon materials in ODH of alkanes.

In this paper, we present the results of liquid low-level radioactive wastes (LLLRW) treatment by direct contact membrane distillation (DCMD) using polyethylene terephthalate (PET) track-etched membranes (TeMs). PET TeMs were modified by styrene and triethoxyvinylsilane (TEVS) using UV-induced grafting. Modification led to increase in the contact angle to 99° of PET TeMs (pore size from 150 to 300 nm). Hydrophobic PET TeMs were investigated by X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), goniometric analysis, gas permeability test, liquid entry presser (LEP) analysis and scanning electron microscope (SEM). Prepared membranes were tested in treatment of LLLRW by DCMD. The influence of pore size on water flux and rejection degree was studied. Rejection degree was evaluated by conductometry and atomic emission methods. Decontamination factors (evaluated by gamma-ray spectroscopy) for 60Co, 137Cs, and 241Am were found to be 85, 1900 and 5 respectively. In most cases degree of rejection of Cs, Mo, Sr, Sb, Al, Ca, Fe, K, Mg and Na ions were more than 90% and close to 100%. The use of TeMs with a narrow pores size distribution and without tortuous channels allowed us to achieve better purification from radioactive wastes in comparison with hollow-fiber membranes. © 2019 Elsevier Ltd

Various random copolymers, poly(styrene-co-ethyl acrylate), were synthesized by free radical bulk copolymerization cocatalyzed by aluminum triflate (Al(OTf)3). The experimental conditions for the polymerization reactions, which include the amount of cocatalyst, polymerization time and ratio of styrene to ethyl acrylate, were investigated. The copolymer molecular weights were determined by gel permeation chromatography coupled to multi-angle laser light scattering. Compositional analysis was performed using proton nuclear magnetic resonance spectrometry. Electron paramagnetic resonance spectroscopy was also used to study the radical species which form in the presence or absence of Al(OTf)3. Kinetic studies were performed by determining monomer conversions as a function of time on gas chromatography. It was found that Al(OTf)3 accelerated the rate of polymerization significantly while also increasing the polymer molecular weights for a given conversion compared to the reactions where the triflate was absent. Al(OTf)3 can be a significantly more cost-effective and abundant alternative polymerization cocatalyst compared to some of the rare lanthanide triflates

For every mass product, there are problems associated with the resulting waste. Residues of hormones in urine cannot be removed sufficiently from wastewater, and this has undesired consequences. An ideal adsorbent would take up the impurity, enable a simple separation and recyclability. Polymer colloids with high affinity towards the drug, accessible porosity, high surface area, and stimuli-responsive properties would be candidates, but such a complex system does not exist. Here, porous vinyl-functionalized organosilica nanoparticles prepared from a styrene bridged sol-gel precursor act as monomers. Initiation of the polymerization at the pore walls and addition of functional monomers result in a special copolymer, which is covalently linked to the surface and covers it. An orthogonal modification of external surface was done by click attachment of a thermoresponsive polymer. The final core-shell system is able to remove quantitatively hydrophobic molecules such as the hormone progesterone from water. A change of temperature closes the pores and induces the aggregation of the particles. After separation one can reopen the particles and recycle them. © 2020 The Authors. Published by Wiley-VCH GmbH

Polystyrene food contact materials can be tainted with unreacted residual styrene monomer from the manufacturing process, which later migrate into food when both materials come into contact. Ingestion of styrene is the main concern as it has been classified in group 2B substance (possibly carcinogenic to humans) by International Agency for Research on Cancer IARC (2002). The risk of styrene monomer migration into Southeast Asian cuisines is imminent as the foods are inherently fatty, often prepared by high-heat cooking methods, and commonly serve at hot state. Additionally, data of styrene monomer migration from High Impact Polystyrene (HIPS) into food at prolong storage is rarely modelled. In this study, the effects of fat content, temperature and contact time on styrene monomer migration from General-Purpose Polystyrene (GPPS) into selected Malaysian dishes and beverage were determined. Distilled water, 3% acetic acid, 10% ethanol and palm olein were prepared in addition to the beef soup, curry noodles and pulled tea at four different amounts of fat-contributing ingredients. Two-sided contact migration cell was filled with food simulants and samples at temperature ranging from 40°C to 70°C at different times. Headspace Solid-Phase Micro Extraction (HS-SPME) coupled with Gas Chromatography–Mass Spectrometry (GC-MS) was used to extract, detect and quantify styrene. Styrene levels in palm olein were found as the highest and significantly differed from other food simulants. Styrene levels in food samples with the highest fat content resulted in the highest levels and significantly differed from other formulations. Food simulants and food samples exposed to 70°C for 2hr were found to have the highest styrene levels compared to other conditions of contact. Subsequently, diffusion model based on Fick’s law was used to examine the migration profile of styrene monomer from HIPS pot into yoghurt at different storage periods. Three different brands of plain stirred yoghurt p

In this work, the potential of a microwave (MW)induced atmospheric pressure plasma jet (APPJ) in film deposition of styrene and methyl methacrylate (MMA) precursors is investigated. Plasma properties during the deposition and resultant coating characteristics are studied. Optical emission spectroscopy (OES) results indicate a higher degree of monomer dissociation in the APPJ with increasing power and a carrier gas flow rate of up to 250 standard cubic centimeters per minute (sccm). Computational fluid dynamic (CFD) simulations demonstrate nonuniform monomer distribution near the substrate and the dependency of the deposition area on the monomercontaining gas flow rate. A nonhomogeneous surface morphology and topography of the deposited coatings is also observed using atomic force microscopy (AFM) and SEM. Coating chemical analysis and wettability are studied by XPS and water contact angle (WCA), respectively. A lower monomer flow rate was found to result in a higher C–O/C–C ratio and a higher wettability of the deposited coatings., V této práci je zkoumán potenciál využití mikrovlnně indukovaného plazmového jetu generovaného za atmosférického tlaku (APPJ) při depozici tenkých filmů z prekurzorů styrenu a metyl-metakrylátu (MMA). Studovány jsou vlastnosti plazmatu během depozice a charakterizace výsledných vrstev. Výsledky z optické emisní spektrometrie (OES) ukazují na vysoký stupeň disociace monomeru v APPJ s rostoucím výkonem a při průtoku nosného plynu do 250 sccm. Simulace pomocí metody CFD ukázala na nejednotnou distribuci monomeru v blízkosti substrátu a závislost oblasti depozice na průtoku plynu obsahujícího monomer. Nehomogenní morfologie a topografie povrchu deponované vrstvy byla také pozorována pomocí mikroskopie atomárních sil (AFM) a SEM. Chemická analýza vrstvy a její smáčivost byly studovány pomocí XPS, respektive měření kontaktního úhlu vody (WCA). Bylo zjištěno, že nižší průtok monomeru vede k vyššímu poměru C–O/C–C a vyšší smáčivosti deponované vrstvy.

In this work, the potential of a microwave (MW)induced atmospheric pressure plasma jet (APPJ) in film deposition of styrene and methyl methacrylate (MMA) precursors is investigated. Plasma properties during the deposition and resultant coating characteristics are studied. Optical emission spectroscopy (OES) results indicate a higher degree of monomer dissociation in the APPJ with increasing power and a carrier gas flow rate of up to 250 standard cubic centimeters per minute (sccm). Computational fluid dynamic (CFD) simulations demonstrate nonuniform monomer distribution near the substrate and the dependency of the deposition area on the monomercontaining gas flow rate. A nonhomogeneous surface morphology and topography of the deposited coatings is also observed using atomic force microscopy (AFM) and SEM. Coating chemical analysis and wettability are studied by XPS and water contact angle (WCA), respectively. A lower monomer flow rate was found to result in a higher C–O/C–C ratio and a higher wettability of the deposited coatings., V této práci je zkoumán potenciál využití mikrovlnně indukovaného plazmového jetu generovaného za atmosférického tlaku (APPJ) při depozici tenkých filmů z prekurzorů styrenu a metyl-metakrylátu (MMA). Studovány jsou vlastnosti plazmatu během depozice a charakterizace výsledných vrstev. Výsledky z optické emisní spektrometrie (OES) ukazují na vysoký stupeň disociace monomeru v APPJ s rostoucím výkonem a při průtoku nosného plynu do 250 sccm. Simulace pomocí metody CFD ukázala na nejednotnou distribuci monomeru v blízkosti substrátu a závislost oblasti depozice na průtoku plynu obsahujícího monomer. Nehomogenní morfologie a topografie povrchu deponované vrstvy byla také pozorována pomocí mikroskopie atomárních sil (AFM) a SEM. Chemická analýza vrstvy a její smáčivost byly studovány pomocí XPS, respektive měření kontaktního úhlu vody (WCA). Bylo zjištěno, že nižší průtok monomeru vede k vyššímu poměru C–O/C–C a vyšší smáčivosti deponované vrstvy.

In this work, the potential of a microwave (MW)induced atmospheric pressure plasma jet (APPJ) in film deposition of styrene and methyl methacrylate (MMA) precursors is investigated. Plasma properties during the deposition and resultant coating characteristics are studied. Optical emission spectroscopy (OES) results indicate a higher degree of monomer dissociation in the APPJ with increasing power and a carrier gas flow rate of up to 250 standard cubic centimeters per minute (sccm). Computational fluid dynamic (CFD) simulations demonstrate nonuniform monomer distribution near the substrate and the dependency of the deposition area on the monomercontaining gas flow rate. A nonhomogeneous surface morphology and topography of the deposited coatings is also observed using atomic force microscopy (AFM) and SEM. Coating chemical analysis and wettability are studied by XPS and water contact angle (WCA), respectively. A lower monomer flow rate was found to result in a higher C–O/C–C ratio and a higher wettability of the deposited coatings., V této práci je zkoumán potenciál využití mikrovlnně indukovaného plazmového jetu generovaného za atmosférického tlaku (APPJ) při depozici tenkých filmů z prekurzorů styrenu a metyl-metakrylátu (MMA). Studovány jsou vlastnosti plazmatu během depozice a charakterizace výsledných vrstev. Výsledky z optické emisní spektrometrie (OES) ukazují na vysoký stupeň disociace monomeru v APPJ s rostoucím výkonem a při průtoku nosného plynu do 250 sccm. Simulace pomocí metody CFD ukázala na nejednotnou distribuci monomeru v blízkosti substrátu a závislost oblasti depozice na průtoku plynu obsahujícího monomer. Nehomogenní morfologie a topografie povrchu deponované vrstvy byla také pozorována pomocí mikroskopie atomárních sil (AFM) a SEM. Chemická analýza vrstvy a její smáčivost byly studovány pomocí XPS, respektive měření kontaktního úhlu vody (WCA). Bylo zjištěno, že nižší průtok monomeru vede k vyššímu poměru C–O/C–C a vyšší smáčivosti deponované vrstvy.

Using potassium ethylxanthate as the chain transfer agent, 2,2’-azobis(isobutyronitrile) (AIBN) as the initiator, reversible addition-fragmentation chain transfer (RAFT) polymerization of styrene was carried out. The influences of reaction temperature, reaction time, and the amounts of the initiator and chain transfer agent on the RAFT polymerization were investigated in terms of monomer conversion, average number molecular weight (Mn) and molecular weight distribution (Ð) of the obtained polymer. Monomer conversion and the Mn of the obtained polystyrene (PS) improved with an increase in the reaction temperature, and the polymerization kinetics exhibited a highly linear relationship, indicating a first-order reaction. When the amounts of the initiator and chain transfer agent were increased, it led to a decreased Mn of the produced PS. Meanwhile, the Ð of the PS was in a relatively narrow range (1.42-1.89). The chain-end functionality was further demonstrated by adding methyl methacrylate to the PS.

Le méthane (CH4), important gaz à effet de serre (GES), a des effets néfastes sur l'environnement en raison de son potentiel de réchauffement global (PRG). Toute mesure conduisant à une réduction des émissions de CH4 mérite d’être encouragée afin de limiter les effets du changement climatique sur la planète. Le procédé de biofiltration est une approche prometteuse pour l'élimination des émissions de CH4 (concentrations inférieures à 5% v/v). Les micro organismes, contenus dans le biofiltre, ont besoin de nutriments supplémentaires, qui sont généralement ajoutés sous forme d’une solution nutritive (NS). L'excès de NS, quittant le biofiltre sous forme de lixiviat, doit être traité dans des stations de traitement des eaux usées (STEP). Le méthane émis par les stations d'épuration, les sites d’enfouissement, les raffineries et les complexes pétrochimiques peut être accompagné de composés aromatiques tels que des vapeurs de styrène (C8H8). Le styrène est un composé cancérigène qui doit être traité comme un gaz résiduel. La présence d’un mélange de CH4 et de C8H8 dans un biofiltre peut entraîner certaines limitations dans les performances du bioprocédé, en raison des effets inhibiteurs du C8H8 sur la biodégradation du CH4. L'objectif principal de cette étude est de réduire la production de lixiviat et d'examiner la capacité du procédé de biofiltration lors du traitement d'un mélange de CH4 et de C8H8. Premièrement, une revue de la littérature a été effectuée sur la production de CH4 dans les stations d'épuration et les réseaux de canalisation des eaux usées, en tant que source mondiale croissante d'émissions de GES, et sur les approches potentielles permettant la bioélimination du CH4. Deuxièmement, deux biofiltres de 18 L (B1 et B2) remplis d’un garnissage inorganique ont été exploités pendant 283 jours sous un temps de résidence en fût vide (EBRT) constant de 6 min et des charges à l'entrée (IL) de CH4 de 7 à 63 g m-3 h-1. Le biofiltre B1 a été alimenté avec une NS fraî, Methane (CH4), as an important greenhouse gas (GHG), has harmful effects on the environment due to its global warming potency (GWP). Any effort leading to a decline in the emission of CH4 could be a worthy step in order to prevent the planet’s climate change. Biofiltration process is a promising approach for CH4 elimination (concentrations below 5% v/v). Microorganisms in a CH4 biofilter need supplementary nutrients, which are usually added as a nutrient solution (NS). The excess NS leaves the biofilter as leachate, which has to be treated in wastewater treatment plants (WWTPs). Methane emitted from WWTPs, landfills, refineries and petrochemical complexes could be accompanied by aromatic compounds such as styrene (C8H8) vapors. Styrene is a carcinogenic compound and should be treated as a waste gas. Presence of CH4 and C8H8 as a mixture in a biofilter may result in some limits for the bioprocess’s performance, due to the inhibitory effects of C8H8 on CH4 biodegradation. The main objective of this study is to reduce the production of leachate and examine the capability of biofiltration process when treating a mixture of CH4 and C8H8. Firstly, a literature review was provided on the production of CH4 in WWTPs and sewer networks, as a growing worldwide source of GHG emission, and on the potential approaches for CH4 bioelimination. Secondly, two 18 L biofilters (B1 and B2) packed with inorganic materials were operated for 283 days under a constant empty bed residence time (EBRT) of 6 min at CH4 inlet loads (ILs) of 7 to 63 g m-3 h-1. Biofilter B1 was fed with a fresh NS every day and B2 was fed with a recycled NS from a 10 L tank in order to use less NS (both were supplied with 2 L d-1 NS, flow rate of 1 L min-1). Maximum CH4 removal efficiency (RE) of 66% (IL of 13 g m-3 h-1) for B1 and 67% (IL of 30 g m-3 h-1) for B2 was observed. Thirdly, four upflow biofilters also packed with inorganic materials were operated at a constant airflow rate of 3 L min-1 to exa

Flow microreactors are expected to make a revolutionary change in chemical synthesis involving various fields of polymer synthesis. In fact, extensive flow microreactor studies have opened up new possibilities in polymer chemistry including cationic polymerization, anionic polymerization, radical polymerization, coordination polymerization, polycondensation and ring-opening polymerization. This review provides an overview of flow microreactors in anionic polymerization and their various applications.

A unique biodegradable polyester film was made from naturally accessible Maravetti crude (Hydnocarpus wightianus), formic acid and 30% hydrogen peroxide, using a step-wise polymerization technique. The polymer was created by reacting resin with styrene. UV, FTIR and NMR spectral studies were carried out to identify the structural characteristics of the polymer product. The biodegradability of the polyester film was investigated using Soil burial test. The thermal deterioration was investigated using TG-DTA analysis at various time intervals. The cross-linking potential of the polymers was determined using DSC analysis. Tensile and impact strengths and other mechanical parameters were assessed. The resultant polymers were found to have acceptable mechanical characteristics and cured quickly.

High molecular weight waterborne ABA block copolymers of styrene (St) and 2-ethylhexyl acrylate (2EHA) containing hard and soft domains were synthesized by means of RAFT (mini)emulsion polymerization using a bifunctional symmetric S,S-dibenzyl trithiocarbonate (DBTTC) RAFT agent. Miniemulsion polymerization was initially used for the synthesis of the A-block, which forms hard domains, followed by 2EHA pre-emulsion feeding to build the B-block soft domains. Polymerization kinetics and the evolution of the Molecular Weight Distribution (MWD) were followed during the synthesis of different ABA block copolymers. The thermal properties of the final symmetric block copolymers were studied on dried films by means of DSC. It was found that the block copolymers have two glass transitions, which indicates the presence of a two-phase system. Phase separation was investigated by means of microscopic techniques (AFM and TEM) and SAXS, both of the particles in the latex form, as well as after film formation at room temperature and after different post-treatments. Films were annealed at temperatures well above the glass transition temperature (T-g) of the hard phase to study the bulk morphology of the films after complete particle coalescence. Moreover, for comparison purposes, the films were re-dissolved in THF, and films were again cast directly from the homogeneous THF solutions. As THF is a good solvent for both blocks, such films serve as a reference for the equilibrium morphology. Finally, DMTA studies of the films annealed at different temperatures were performed to correlate the morphology changes with the mechanical properties of the block

This work is dealing with the fracture behaviour of carbon-black reinforced styrene- butadiene rubber (SBR) vulcanizates with modified renewable oils (bio-oils) e.g. epoxidized ester of glycerol from canola oil (EECO). For comparing the results, parallel the conventional oil treated distillate aromatic extract (TDAE) was used. Materials were compounded and vulcanized. The fracture mechanics behaviour under quasi-static and impact loading was investigated under consideration of various specimen geometries. Single-edged notch tension (SENT), double-edged notch tension (DENT), and pure shear specimens were used to investigate the crack resistance (J), crack propagation energy (TJ*), and crack toughness (Jd) values. Simultaneously, the hardness, tear and tensile behaviour, visco-elastic properties, thermal degradation and oil migration tests were done to analyze the material behaviour intensively. Finally, the specimens were aged for different times in a hot air oven (80 °C). After that, fracture mechanics and mechanical behaviours were analyzed. It was found that the SBR vulcanizates with bio-oils showed improved fracture mechanics behaviour compared to conventional oil. As well as the mechanical properties of SBR vulcanizates with bio-oils increased. After thermo-oxidative aging, the fracture mechanics behaviour of SBR with bio-oils is comparable and some mechanical results are better than those from the compound with the conventional oil, This work is dealing with the fracture behaviour of carbon-black reinforced styrene- butadiene rubber (SBR) vulcanizates with modified renewable oils (bio-oils) e.g. epoxidized ester of glycerol from canola oil (EECO). For comparing the results, parallel the conventional oil treated distillate aromatic extract (TDAE) was used. Materials were compounded and vulcanized. The fracture mechanics behaviour under quasi-static and impact loading was investigated under consideration of various specimen geometries. Single-edged notch tension (SENT), double-edged notch tension (DENT), and pure shear specimens were used to investigate the crack resistance (J), crack propagation energy (TJ*), and crack toughness (Jd) values. Simultaneously, the hardness, tear and tensile behaviour, visco-elastic properties, thermal degradation and oil migration tests were done to analyze the material behaviour intensively. Finally, the specimens were aged for different times in a hot air oven (80 °C). After that, fracture mechanics and mechanical behaviours were analyzed. It was found that the SBR vulcanizates with bio-oils showed improved fracture mechanics behaviour compared to conventional oil. As well as the mechanical properties of SBR vulcanizates with bio-oils increased. After thermo-oxidative aging, the fracture mechanics behaviour of SBR with bio-oils is comparable and some mechanical results are better than those from the compound with the conventional oil

The stereoselective polymerization of the linear terpenes P-myrcene and P-ocimene and their binary copolymerizations with styrene and butadiene promoted by titanium complexes dichloro{l,4-dithiabutanediyl-2,2' -bis( 4,6-di-tert-butyl-phenyl)}titanium (1) or dichloro{l,4- dithiabutanediyl-2,2' -bis[ 4,6-bis(2-phenyl-2-propyl)phenoxy]}titanium (2) activated by methylaluminoxane (MAO) is reported. In the homopolymerization of P-myrcene, complex 1 and 2 led obtaining a polymer with a mainly 1,4-trans microstructure (92% and 60% of stereoselectivity, respectively). In the case of P-ocimene, both catalysts produce a polymer with l,4-trans structure (70%) at 70 °C while at a lower temperature (0 °C) an isotactic poly-1,2-ocimene (selectivity up to 99%) is obtained. Copolymerizations of P-myrcene and P-ocimene with styrene or butadiene, catalyzed by complexes 1 or 2 were also carried on, giving the corresponding binary copolymers in a wide range of compositions through judicious control of the alimentation feed, The stereoselective polymerization of the linear terpenes P-myrcene and P-ocimene and their binary copolymerizations with styrene and butadiene promoted by titanium complexes dichloro{l,4-dithiabutanediyl-2,2' -bis( 4,6-di-tert-butyl-phenyl)}titanium (1) or dichloro{l,4- dithiabutanediyl-2,2' -bis[ 4,6-bis(2-phenyl-2-propyl)phenoxy]}titanium (2) activated by methylaluminoxane (MAO) is reported. In the homopolymerization of P-myrcene, complex 1 and 2 led obtaining a polymer with a mainly 1,4-trans microstructure (92% and 60% of stereoselectivity, respectively). In the case of P-ocimene, both catalysts produce a polymer with l,4-trans structure (70%) at 70 °C while at a lower temperature (0 °C) an isotactic poly-1,2-ocimene (selectivity up to 99%) is obtained. Copolymerizations of P-myrcene and P-ocimene with styrene or butadiene, catalyzed by complexes 1 or 2 were also carried on, giving the corresponding binary copolymers in a wide range of compositions through judicious control of the alimentation feed

U okviru ove doktorske disertacije proučavan je uticaj različitih uslova fermentacijena produkciju levana bakterije Bacillus lichenifomis NS032, ispitivana struktura dobijenogpolisaharida i sintetisani kalemljeni kopolimeri levana i polistirena (Lev-g-PS).U prvoj seriji eksperimenata optimizovane su podloge za produkciju levanatehnikom jedne promenljive u vremenu i metodom površine odgovora. Najviši prinosipolisaharida se dobijaju na temperaturi od 37 °C i bez mešanja. Upotrebom podloge sa196,75 g/L saharoze, 2,44 g/L amonijum-hlorida i inicijalnog pH od 6,97 dobija se 47,84g/L levana LS200, a na podlozi sa 397,65 g/L saharoze, 4,62 g/L amonijum-hlorida iinicijalnog pH od 7,31 dobija se 99,19 g/L levana LS400. U sledećim uslovima: 62,6 %melase, 4,66 g/L fosfata i inicijalnim pH od 7,2 dobija se 53,6 g/L levana LM.Strukturna ispitivanja (kisela hidroliza, metilaciona analiza, FTIR, 13C- i 1H-NMR,COSY, HSQC i HMBC) su pokazala da su dobijeni levani polifruktani sa β-(2,6)-glikozidnom vezom u osnovnom nizu i grananjem u položaju β-(2,1). Stepeni grananja su11,04 ± 0,57 %, 11,99 ± 0,63 % 12,68 ± 0,71 % za levane LS200, LS400 i LMrespektivno. Levani LS200 i LM relativno su visoke molekulske mase (opseg > 106 Da) saviskozitetima 0,25 dL/g i 0,24 dL/g, dok je levan LS400 niže molekulske mase (105 Da) iviskoziteta 0,14 dL/g.U poslednjoj seriji eksperimenata ispitivan je uticaj različitih reakcionih uslova nasintezu Lev-g-PS slobodnoradikalskim mehanizmom i upotrebom kalijum-persulfata kaoinicijatora. Maksimalni G (%) = 58,1 dobijen je na 70 °C, u atmosferi azota i upotrebomaminoaktivatora DMEA. FTIR, SEM, TG/DTA, XRD i 13C NMR spektroskopija dobijenogkopolimera su pokazali da je došlo do reakcije kalemljenja između levana i polistirena., Within this doctoral dissertation, the effects of various fermentation factors on levanproduction by Bacillus lichenifomis NS032 were studied, structure of obtainedpolysaccharide was investigated and grafted copolymers of levan and polystyrene (Lev-g-PS) were synthetized.In the first series of experiments, media for levan production were optimized usingone factor at a time and response surface methods. The highest levan yield was obtained at37 °C and without agitation. Using the medium with 196.75 g/L sucrose, 2.44 g/Lammonium chloride and pH 6.97, obtained amount of LS200 levan was 47.84 g/L and inmedium with 397.65 g/L sucrose, 4.62 g/L ammonium chloride and pH 7.31 amount ofLS400 levan was 99.19 g/L. In the following conditions: 62.6 % molasses, 4.66 g/Lphosphate and an initial pH 7.2, LM levan (53.6 g/L) was obtained.Structural characterization (acid hydrolisis, methylation analysis, FTIR, 13C- and1H-NMR, COSY, HSQC i HMBC) showed that investigated levans are polyfructans with β-(2,6)- glycosidic linkages in backbone and branching through β-(2,1) positions. The extentsof branching are 11.04 ± 0.57 %, 11.99 ± 0.63 % 12.68 ± 0.71 % for LS200, LS400 andLM levans, respectively. LS200 and LM have relatively high molecular weight (range >106 Da) and viscosity (0.25 dL/g and 0.24 dL/g), contrary to LS400 with lower molecularweight (105 Da) and viscosity (0.14 dL/g).Finally, influence of different reaction conditions on synthesis of Lev-g-PS by freeradical mechanism and potassium persulfate as initiator was investigated. Maximum G (%)= 58.1 was obtained at 70 °C, in nitrogen atmosphere and using the amine activator DMEA.FTIR, SEM, TG/DTA, XRD and 13C NMR spectroscopy of copolymer showed thatgrafting reaction of levan and polystyrene was successful.

Waste to energy is a key driver to achieve a clean and virtuous renewable cycle. Among others, the processes to convert organic matter in wastes from automotive residues, mainly composed of rubbers and foams [ethylene propylene diene monomer (EPDM) and polyurethane (PUR)], polyolefin plastics [polypropylene (PP) and polyethylene (PE)], styrenic plastics [acrylonitrile butadiene styrene (ABS) and polystyrene (PS)], and other thermoplastics [polyvinyl chloride (PVC) and polycarbonate (PC)], into a liquid fuel are now reliable. This new, atypical, and uncharted fuel is expected to emit large levels of pollutants, bringing new challenges that must be resolved by the combustion community. Advanced combustion modes appear to be a solution to enhance the efficiency and cutoff the NOx and soot particle emissions. The present paper addresses the scarcity of experimental data by investigating the autoignition in a rapid compression machine. The pressure and temperature were swept from 10 to 20 bar and from 700 to 880 K, respectively, and the equivalence ratio was equal to 0.5. These conditions match with the homogeneous charge compression ignition (HCCI) mode operating with exhaust gas recirculation, especially for the low to intermediate (intermediate to high) temperature (pressure). The studied fuel is the light fraction of the synthetic crude oil, described by high-alkene and high-oxygenate levels. Several specificities have been detected: A limited low-temperature reactivity and a low negative temperature coefficient. Combustion simulation will be carried out in further work to determine to what extent advanced combustion modes will play a role to achieve a clean combustion in a waste-to-energy perspective. © 2019 American Chemical Society.

By employing large-scale molecular dynamics simulations of atomistically resolved oligoelectrolytes in aqueous solutions, we study in detail the first four layer-by-layer deposition cycles of an oligoelectrolyte multilayer made of poly(diallyl dimethyl ammonium chloride)/poly(styrene sulfonate sodium salt) (PDADMAC/PSS). The multilayers are grown on a silica substrate in 0.1 M NaCl electrolyte solutions and the swollen structures are then subsequently exposed to varying added salt concentration. We investigated the microscopic properties of the films, analyzing in detail the differences between three- and four-layer systems. Our simulations provide insights into the early stages of growth of a multilayer, which are particularly challenging for experimental observations. We found rather strong complexation of the oligoelectrolytes, with fuzzy layering of the film structure. The main charge compensation mechanism is for all cases intrinsic, whereas extrinsic compensation is relatively enhanced for the layer of the last deposition cycle. In addition, we quantified other fundamental observables of these systems, such as the film thickness, water uptake, and overcharge fractions for each deposition layer. This journal is © The Royal Society of Chemistry.

Bark beetles kill apparently vigorous conifers during epidemics by means of pheromone-mediated aggregation. During non-endemic conditions the beetles are limited to use trees with poor defense, like wind-thrown. To find olfactory cues that help beetles to distinguish between trees with strong or weak defense, we collected volatiles from the bark surface of healthy felled or standing Picea abies trees. Furthermore, living trees were treated with methyl jasmonate in order to induce defense responses. Volatiles were analyzed by combined gas chromatography and electroantennographic detection (GC-EAD) on Ips typographus antennae. Compounds eliciting antennal responses were characterized by single sensillum recording for identification of specific olfactory sensory neurons (OSN). Release of monoterpene hydrocarbons decreased, while oxygenated compounds increased, from spring to early summer in felled trees. In both beetle sexes particular strong EAD activity was elicited by trace amounts of terpene alcohols and ketones. 4-Thujanol gave a very strong response and the absolute configuration of the tested natural product was assigned to be (+)-trans-(1R,4S,5S)-thujanol by stereoselective synthesis and enantioselective gas chromatography. One type of OSN responded to all ketones and five other OSN were characterized by the type of compounds that elicited responses. Three new OSN classes were found. Of the eight EAD-active compounds found in methyl jasmonate-treated bark, the known anti-attractant 1,8-cineole was the one most strongly induced. Our data support the hypothesis that highly active oxygenated host volatiles could serve as positive or negative cues for host selection in I. typographus and in other bark beetles.

Transparent wood composites, with their high strength and toughness, thermal insulation, and excellent transmissivity, offer a route to replace glass for diffusely transmitting windows. Here, conjugated-polymer-based electrochromic devices (ECDs) that switch on-demand are demonstrated using transparent wood coated with poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) as a transparent conducting electrode. These ECDs exhibit a vibrant magenta-to-clear color change that results from a remarkably colorless bleached state. Furthermore, they require low energy and power inputs of 3 mWh m−2 at 2 W m−2 to switch due to a high coloration efficiency (590 cm2 C−1) and low driving voltage (0.8 V). Each device component is processed with high-throughput methods, which highlights the opportunity to apply this approach to fabricate mechanically robust, energy-efficient smart windows on a large scale., QC 20200514

Mixed plastics and papers are two of the main fractions in municipal solid waste which is a critical environmental issue today. Recovering energy and chemicals from this waste stream by pyrolysis is one of the favorable options to achieve a circular economy. While pyrolysis products from plastics are mainly hydrocarbons, pyrolysis products from paper/biomass are highly oxygenated. The different nature of the two pyrolysis products results in different treatments and applications as well as economic values. Therefore, separation of these two products by multi-step pyrolysis based on their different decomposition temperatures could be beneficial for downstream processes to recover materials, chemicals and/or energy. In this work, stepwise pyrolysis of mixed plastics and paper waste was performed in a batch type fixed bed reactor using two different pyrolysis temperatures. Neat plastic materials (polystyrene, polyethylene) and cellulose mixtures were used as starting materials. Then, the same conditions were applied to a mixed plastics and paper residue stream derived from paper recycling process. The condensable products were analyzed by GC/MS. It was found that pyrolysis temperatures during the first and second step of 350 and 500 °C resulted in a better separation of the oxygenated and hydrocarbon condensates than when a lower pyrolysis temperature (300 °C) was used in the first step. The products from the first step were derived from cellulose with some heavy fraction of styrene oligomers, while the products from the second step were mainly hydrocarbons derived from polystyrene and polyethylene. This thus shows that stepwise pyrolysis can separate the products from these materials, although with some degree of overlapping products. Indications of interaction between PS and cellulose during stepwise pyrolysis were observed including an increase in char yield, a decrease in liquid yield from the first temperature step and changes in liquid composition, compared to st, QC 20181119

In the present study, graft copolymer with microbial levan and styrene was synthetized, characterized and its biodegradable potential was investigated.

Macrodiscs, which are magnetically alignable lipid bilayer discs with diameters of >30 nm, were obtained by solubilizing protein-containing liposomes with styrene-maleic acid copolymers. Macrodiscs provide a detergent-free phospholipid bilayer environment for biophysical and functional studies of membrane proteins under physiological conditions. The narrow resonance linewidths observed from membrane proteins in styrene-maleic acid macrodiscs advance structure determination by oriented sample solid-state NMR spectroscopy.

Cilj ovog rada je bio izolovati i upotrebiti mikrobni levan za sintezu novog tipa kalemljenog kopolimera sa stirenom i ispitati uticaj aminoaktivatora na reakciju kalemljenja., The aim of this study was to isolate and use microbial levan for the synthesis of a new type of grafted copolymer with styrene and to investigate the influence of amino activators on the grafting reaction.

Background: Process simulation has been extensively used in recent years to design, evaluate or optimize processes, systems and specific operations of the chemical industry and its related disciplines. Currently, CHEMCAD® constitute one of the most used process simulators because of the great number of chemical and petrochemical processes that can be simulated.Method: The simulation of the production process of styrene via catalytic dehydrogenation of ethyl-benzene is carried out by using the process simulator CHEMCAD® version 5.2.0, in order to determine the composition and mass flow-rate of each process involved in the production, as well as the main operating parameters of the equipment used. Two sensitivity studies were carried out: firstly, the influence of the temperature and pressure values applied at the LLV Separator on the amounts of ethyl-benzene and styrene to be obtained by the intermediate and top currents of this equipment; secondly, the influence of the operating pressure of the Distillation Column No. 1 (benzene-toluene column) on the quantity of ethyl-benzene and styrene obtained at the bottom stream. The simulating software MATLAB® version 7.8.0 was used to process the results obtained.Results: Around 9234.436 kg/h of styrene is obtained in the last distillation column with 99.6% purity. Additionally, it was found that the water is the main impurity found on this stream, which represents 0.35% of the weight.Conclusions: The LLV Separator must operate at a low temperature (5 – 10 ºC) and at a relatively high pressure (10 bar), whereas the Distillation Column No. 1 must work at a pressure near atmospheric (1.0 bar), or preferably under vacuum conditions in order to obtain the highest yields of styrene and ethyl-benzene., Contexto: la simulación de procesos se ha venido utilizando extensivamente en los últimos años con el propósito de diseñar, evaluar u optimizar procesos, sistemas u operaciones específicos de la industria química y sus ramas afines. Uno de los simuladores de procesos más empleados en la actualidad es el CHEMCAD®, mediante el cual se pueden simular un gran número de procesos químicos y petroquímicos.Método: se lleva a cabo la simulación del proceso de producción del estireno a partir de la deshidrogenación catalítica del etilbenceno, utilizando el simulador de procesos CHEMCAD® versión 5.2.0., con el fin de conocer la composición y el flujo másico de cada una de las corrientes de proceso, así como también los principales parámetros de operación de los equipos utilizados. Se efectuaron dos estudios de sensibilidad: 1) influencia de los valores de temperatura y presión aplicados en el Separador LLV sobre las cantidades de etilbenceno y estireno a obtener por la corriente intermedia y del tope de este equipo; y 2) influencia de la presión de operación de la Columna de Destilación No. 1 sobre la cantidad de estireno y etilbenceno que sale por el fondo de ésta. Se empleó además el simulador MATLAB®, versión 7.8.0, para procesar los resultados obtenidosResultados: en la última columna de destilación se obtienen 9234.436 kg/h de estireno con un 99.6 % de pureza, siendo la principal impureza encontrada en esta corriente el agua, con 0.35% en masa.Conclusiones: el Separador LLV deberá operarse a una temperatura baja (5 – 10 ºC) y a una presión relativamente alta (10 bar), mientras que la Columna de Destilación No. 1 deberá operar a una presión cercana a la atmosférica (1.0 bar) o, preferiblemente, bajo condiciones de vacío, para obtener los mejores rendimientos de estireno y etilbenceno.

Peer Reviewed, Postprint (author's final draft)

Peer Reviewed, Postprint (author's final draft)

Novel macromolecular graft copolymers were synthesized by reaction of the hydroxyl groups of the microbial polysaccharide levan, produced using Bacillus licheniformis, with polystyrene (Lev-g-PS). Synthesis was performed by the free radical reaction using potassium persulfate (PPS) as initiator. The prepared copolymer was characterized by FTIR, SEM, TG/DTA, XRD and C-13 NMR. The influence of the different conditions (reaction temperature, air or nitrogen atmosphere, reaction time, type of amines and ascorbic acid (AA) concentration) on the grafting reaction was investigated. Results showed that maximum percentage of grafting (58.1%) was achieved at a reaction temperature 70 degrees C, in a nitrogen atmosphere and using dimethylethanolamine (DMEA) as the amine activator. On the basis of the obtained results, the likely reaction mechanism was proposed. Synthesized copolymers have better thermal stability in comparison with their initial components. Copolymers such as Lev-g-PS could potentially have many applications, such as compatibilizers and material for membranes.

Palladium complexes have the ability to catalyse cross-coupling of two organic moieties through the formation of transient metal-carbon bonds, thus bringing them closer to each other to facilitate the formation of a new bond. Palladium-catalysed coupling reactions are one of the most important carbon-carbon forming reactions available to organic chemists and many of these reactions rely on the reactivity of aryl-palladium complexes. The investigation of new aryl-palladium precursors is thus of great interest, especially as more sustainable and economic methods can be developed. This thesis describes the use of carboxylic acids and sodium arylsulfinates as such new arylating agents. Protocols for microwave-assisted palladium(II)-catalysed decarboxylative synthesis of electron-rich styrenes and 1,1-diarylethenes were developed. However, these transformations had very limited substrate scopes which prompted the investigation of sodium arylsulfinates as alternative arylating agents. These substrates were employed in the microwave-assisted palladium(II)-catalysed desulfitative addition to nitriles, and the substrate scope was demonstrated by combining a wide array of sodium arylsulfinates and nitriles to yield the corresponding aryl ketones. The application of the desulfitative reaction in a continuous flow setup was demonstrated, and aluminium oxide was identified as safe alternative to borosilicate glass as a reactor material. The mechanisms of the decarboxylative and desulfitative transformations were investigated by density functional theory (DFT) calculations. The desulfitative reaction was also investigated by direct electrospray ionization mass spectrometry (ESI-MS), providing further mechanistic insight. Finally, a protocol for the safe and convenient synthesis of a wide range of sodium arylsulfinates was developed.

The copper-catalyzed intermolecular enantioselective addition of styrenes to imines has been achieved under mild conditions at ambient temperature. This process features the use of styrenes as latent carbanion equivalents via the intermediacy of catalytically generated benzylcopper derivatives, providing an effective means for accessing highly enantiomerically enriched amines bearing contiguous stereocenters. Mechanistic studies shed light on the origin of the preferential styrene hydrocupration in the presence of an imine with the Ph-BPE-derived copper catalyst.

Kuraray has developed a series of liquid rubber products with molecular weights ranging from a few thousands to a hundred thousand. These polymers, which consist of isoprene, butadiene, styrene and a new, bio-based monomer “Farnesene”, can be used by rubber manufacturers to achieve improvements in processing and physical properties. The most valuable physical property enhancement liquid butadiene rubber offers is a performance improvement in wet and ice grip, as well as plasticizing effect. Moreover, liquid Farnesene rubber contributes to advantaged vehicle fuel economy through reduction in tire rolling resistance. The application of each liquid rubber product in tire formulations is explained., Kuraray has developed a series of liquid rubber products with molecular weights ranging from a few thousands to a hundred thousand. These polymers, which consist of isoprene, butadiene, styrene and a new, bio-based monomer “Farnesene”, can be used by rubber manufacturers to achieve improvements in processing and physical properties. The most valuable physical property enhancement liquid butadiene rubber offers is a performance improvement in wet and ice grip, as well as plasticizing effect. Moreover, liquid Farnesene rubber contributes to advantaged vehicle fuel economy through reduction in tire rolling resistance. The application of each liquid rubber product in tire formulations is explained.

Polarity and tendency to crystallization are responsible for poor dispersion of sulphur in unpolar rubber matrix, and its tendency to surface blooming in rubber vulcanizates. First attempts to set polymeric structure of sulphur were based on lowering of its polymerization temperature by addition of selenium or reaction activation by laser treatment. However, such polymeric structures are energetically unstable - susceptibility to recrystallization deteriorates its mechanical properties. In order to fix polymeric structure of sulphur one can apply unsaturated organic compounds, taking part in radical copolymerization with sulphur. The most popular comonomers used for this purpose, described in the subject literature, are: dicyclopentadiene, styrene, various disulphides and recently 1,3-diizopropylobenzene. The promising direction seems to be the utilization of compounds synthesized from renewable resources originated from biomass (turpentine, furfural and their derivatives) or received from recycling, e.g. pyrolysis of tyres (pyrolytic oil), Polarity and tendency to crystallization are responsible for poor dispersion of sulphur in unpolar rubber matrix, and its tendency to surface blooming in rubber vulcanizates. First attempts to set polymeric structure of sulphur were based on lowering of its polymerization temperature by addition of selenium or reaction activation by laser treatment. However, such polymeric structures are energetically unstable - susceptibility to recrystallization deteriorates its mechanical properties. In order to fix polymeric structure of sulphur one can apply unsaturated organic compounds, taking part in radical copolymerization with sulphur. The most popular comonomers used for this purpose, described in the subject literature, are: dicyclopentadiene, styrene, various disulphides and recently 1,3-diizopropylobenzene. The promising direction seems to be the utilization of compounds synthesized from renewable resources originated from biomass (turpentine, furfural and their derivatives) or received from recycling, e.g. pyrolysis of tyres (pyrolytic oil)

We introduce a universal high resolution mass spectrometric method for the analysis of poly(ionic liquid)s (PILs), which belong to the most challenging polyelectrolytes from an analytical perspective, by fusing high resolution collision-induced dissociation (CID)-Orbitrap mass spectrometry (MS) with supercharging agents as well as quadrupole time-of-flight (QToF) MS. The study includes a wide array of hydrophilic halide-containing PILs, which were analyzed in negative mode. The influence of the core structures (based on imidazolium, triazolium, ammonium, phosphonium and pyridinium moieties), and variable styrene-, acrylate- and vinyl-type IL polymers on the ionization behavior is mapped in detail. Variable end group functionalities were introduced via functional chain transfer agents (CTA) in reversible addition-fragmentation chain transfer (RAFT) polymerization to study their behavior during the MS analysis. Furthermore, the demanding class of vinylimidazolium halide IL polymers was investigated. The current contribution thus introduces a new analytical technology platform for an entire polymer class. © 2016 The Royal Society of Chemistry.