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The Oseberg Viking ship burial is one of the most extensive collections of Viking wooden artefacts ever excavated in Norway. In the early twentieth century, many of these artefacts were treated with alum in order to preserve them, inadvertently leading to their current degraded state. It is therefore crucial to develop new bioinspired polymers which could be used to conserve these artefacts and prevent further disintegration. Two hydroxylated polymers were synthesised (TPA6 and TPA7), using α-pinene- and oleic acid-derived monomers functionalised with an acrylate moiety. Characterisation using biomolecular hydrodynamics (analytical ultracentrifugation and high precision viscometry) has shown that these polymers have properties which would potentially make them good wood consolidants. Conformation analyses with the viscosity increment (ν) universal hydrodynamic parameter and ELLIPS1 software showed that both polymers had extended conformations, facilitating in situ networking when applied to wood. SEDFIT-MSTAR analyses of sedimentation equilibrium data indicates a weight average molar mass Mw of (3.9 ± 0.8) kDa and (4.2 ± 0.2) kDa for TPA6 and TPA7 respectively. Analyses with SEDFIT (sedimentation velocity) and MultiSig however revealed that TPA7 had a much greater homogeneity and a lower proportion of aggregation. These studies suggest that both these polymers—particularly TPA7—have characteristics suitable for wood consolidation, such as an optimal molar mass, conformation and a hydroxylated nature, making them interesting leads for further research. [ABSTRACT FROM AUTHOR]

Trypanosomatids regulate gene expression mainly at the post‐transcriptional level through processing, exporting and stabilising mRNA and control of translation. In most eukaryotes, protein synthesis is regulated by phosphorylation of eukaryotic initiation factor 2 (eIF2) at serine 51. Phosphorylation halts overall translation by decreasing availability of initiator tRNAmet to form translating ribosomes. In trypanosomatids, the N‐terminus of eIF2α is extended with threonine 169 the homologous phosphorylated residue. Here, we evaluated whether eIF2α phosphorylation varies during the Trypanosoma cruzi life cycle, the etiological agent of Chagas' disease. Total levels of eIF2α are diminished in infective and non‐replicative trypomastigotes compared with proliferative forms from the intestine of the insect vector or amastigotes from mammalian cells, consistent with decreased protein synthesis reported in infective forms. eIF2α phosphorylation increases in proliferative intracellular forms prior to differentiation into trypomastigotes. Parasites overexpressing eIF2αT169A or with an endogenous CRISPR/Cas9‐generated eIF2αT169A mutation were created and analysis revealed alterations to the proteome, largely unrelated to the presence of μORF in epimastigotes. eIF2αT169A mutant parasites produced fewer trypomastigotes with lower infectivity than wild type, with increased levels of sialylated mucins and oligomannose glycoproteins, and decreased galactofuranose epitopes and the surface protease GP63 on the cell surface. We conclude that eIF2α expression and phosphorylation levels affect proteins relevant for intracellular progression of T. cruzi. [ABSTRACT FROM AUTHOR]

SUMMARY: Soybean (Glycine max [L.] Merr.) is a major crop in animal feed and human nutrition, mainly for its rich protein and oil contents. The remarkable rise in soybean transcriptome studies over the past 5 years generated an enormous amount of RNA‐seq data, encompassing various tissues, developmental conditions and genotypes. In this study, we have collected data from 1298 publicly available soybean transcriptome samples, processed the raw sequencing reads and mapped them to the soybean reference genome in a systematic fashion. We found that 94% of the annotated genes (52 737/56 044) had detectable expression in at least one sample. Unsupervised clustering revealed three major groups, comprising samples from aerial, underground and seed/seed‐related parts. We found 452 genes with uniform and constant expression levels, supporting their roles as housekeeping genes. On the other hand, 1349 genes showed heavily biased expression patterns towards particular tissues. A transcript‐level analysis revealed that 95% (70 963 of 74 490) of the assembled transcripts have intron chains exactly matching those from known transcripts, whereas 3256 assembled transcripts represent potentially novel splicing isoforms. The dataset compiled here constitute a new resource for the community, which can be downloaded or accessed through a user‐friendly web interface at http://venanciogroup.uenf.br/resources/. This comprehensive transcriptome atlas will likely accelerate research on soybean genetics and genomics. Significance Statement: Here we report an integrative and systematic analysis of 1298 RNA‐Seq samples to build a soybean gene expression atlas. This resource is accessible via a user‐friendly web interface as well as available for download. [ABSTRACT FROM AUTHOR]

The iron‐containing imidazolium‐based ionic liquids (ILs) 1‐n‐butyl‐3‐methylimidazolium heptachlorodiferrate (BMI.Fe2Cl7) and 1‐n‐butyl‐3‐methylimidazolium tetrachloroferrate (BMI.FeCl4) are applied as catalysts in the homogeneous polymerization of n‐butyl vinyl ether. Both solventless conditions as well as using different organic solvents, catalyst concentrations, temperatures, and reaction times are tested to assess the polymerization conditions that lead to the highest molecular weights of poly(n‐butyl vinyl ether). The Lewis acidic IL BMI.Fe2Cl7 proves to be highly efficient, even at low catalyst concentrations. In bulk polymerization, polymers with 142 kg mol−1 are obtained using a 1:10000 molar ratio of catalyst to monomer. In solution polymerization, the monomer consumption is also rapid and the molecular weight of the polymer is related to the catalyst concentration used. These results indicate the potential of this catalyst for industrial applications. In contrast with the acidic IL, the neutral iron‐containing imidazolium‐based IL BMI.FeCl4 does not show any catalytic activity. [ABSTRACT FROM AUTHOR]

The current work describes the synthesis of a new polyHIPE‐like sulfonated poly(styrene‐co‐n‐acylglycerol) and its use as an efficient heterogeneous catalyst to convert oleic acid into methyl oleate in esterification reactions. This new environmentally friendly polymer incorporates n‐acylglycerol macromonomer as a versatile strategy for glycerol valorization. Macroporous micrometric polymer particles are synthesized through suspension polymerization process without using porogenic agents. polyHIPE‐like copolymers formed with different feed compositions of styrene and n‐acylglycerol are chemically modified via sulfonation reactions to form a highly efficient catalyst for esterification of oleic acid to methyl oleate, exhibiting conversions lying in the interval from 52% to 96%, depending mainly on the amount of n‐acylglycerol macromonomer into the copolymer chains. The experimental results indicate the great potential of this new heterogeneous catalyst based on modified poly(styrene‐co‐n‐acylglycerol) to be successfully employed in esterification reactions of vegetable oils intended for the production of long chain alkyl esters of carboxylic acids, widely used as biofuels. [ABSTRACT FROM AUTHOR]

ABSTRACT Polymers based on renewable sources are promising materials, and can find many uses in coatings and adhesive applications. The goal of this work was to synthesize and characterize bio-based styrene/acrylated fatty acid methyl ester (AFAME) copolymer-poly(styrene- co-AFAME) prepared by miniemulsion polymerization. The main strategy adopted was to functionalize the bio-monomer with acrylic acid that was confirmed by 1H NMR and FTIR measurements, to allow its free-radical homo- or copolymerization with styrene. Poly(styrene- co-AFAME) with different AFAME content were obtained and their composition were evaluated by 1H NMR. Dynamic light scattering measurements throughout the reactions have indicated a very stable colloidal systems and average particles size ranges 100-150 nm. The structural and physical properties of poly(styrene- co-AFAME) were investigated by DTG-DTA, DSC which displayed a decreasing of glass transition temperature with increase of AFAME content. The results showed in this study have indicated that the poly(styrene- co-AFAME) can be used in several fields because their characteristics are totally distinct. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 1422-1432 [ABSTRACT FROM AUTHOR]

The present work addresses the synthesis and characterization of a new bio-nanocomposite based on acrylated fatty acids (AFA) derived from castor oil, ethyl acrylate and AFA surface modified γ-Fe 2 O 3 (γ-Fe 2 O 3 @AFA) magnetic nanoparticles (MNPs). It was shown that the in situ formed bio-nanocomposite containing around 2.0 wt.% of γ-Fe 2 O 3 MNPs with average particle size of ca. 9.0 nm, as determined by XRD and TEM measurements, displayed good magnetic response and superparamagnetic behavior. The magnetization measurements indicated that the incorporation of γ-Fe 2 O 3 @AFA MNPs into the poly(ethyl acrylate- co -AFA) matrix did not affect the magnetization saturation, remanence and coercivity of the MNPs, preserving the magnetic properties of the γ-Fe 2 O 3 precursor. Additionally, the use of AFA to chemically modify the surface of MNPs opens a new scenario on the chemical modification of MNPs with agents that undergo free-radical reactions, allowing for the proper dispersion of MNPs into the thermoplastic polymer matrices and minimizes the undesired leaching of the MNPs. [ABSTRACT FROM AUTHOR]

Iron-containing imidazolium-based ionic liquids were successfully applied as catalysts in the styrene polymerization. Solventless conditions, organic solvents and different imidazolium-based ionic liquid catalysts were tested to evaluate the best reaction conditions. The ionic liquids BMI.FeCl 4 and BMI.Fe 2 Cl 7 showed very distinct catalytic activities. Schulz–Flory distributions indicate two or three active catalytic species in different distributions. Via on-line direct infusion electrospray (tandem) mass spectrometry (ESI-MS(/MS)) reaction monitoring, both active catalytic species in accordance with the Schulz–Flory distributions were intercepted and characterized, providing important mechanistic insights that allowed us to propose a rationale for the origin of the superior catalytic efficiency. [ABSTRACT FROM AUTHOR]

X-chromosome inactivation (XCI) is the epigenetic transcriptional silencing of an X-chromosome during the early stages of embryonic development in female eutherian mammals. XCI assures monoallelic expression in each cell and compensation for dosage-sensitive X-linked genes between females (XX) and males (XY). DNA methylation at the carbon-5 position of the cytosine pyrimidine ring in the context of a CpG dinucleotide sequence (5meCpG) in promoter regions is a key epigenetic marker for transcriptional gene silencing. Using computational analysis, we revealed an extragenic tandem GAAA repeat 230-bp from the landmark CpG island of the human X-linked retinitis pigmentosa 2 RP2 promoter whose 5meCpG status correlates with XCI. We used this RP2 onshore tandem GAAA repeat to develop an allele-specific 5meCpG-based PCR assay that is highly concordant with the human androgen receptor (AR) exonic tandem CAG repeat-based standard HUMARA assay in discriminating active (Xa) from inactive (Xi) X-chromosomes. The RP2 onshore tandem GAAA repeat contains neutral features that are lacking in the AR disease-linked tandem CAG repeat, is highly polymorphic (heterozygosity rates approximately 0.8) and shows minimal variation in the Xa/Xi ratio. The combined informativeness of RP2/AR is approximately 0.97, and this assay excels at determining the 5meCpG status of alleles at the Xp (RP2) and Xq (AR) chromosome arms in a single reaction. These findings are relevant and directly translatable to nonhuman primate models of XCI in which the AR CAG-repeat is monomorphic. We conducted the RP2 onshore tandem GAAA repeat assay in the naturally occurring chimeric New World monkey marmoset (Callitrichidae) and found it to be informative. The RP2 onshore tandem GAAA repeat will facilitate studies on the variable phenotypic expression of dominant and recessive X-linked diseases, epigenetic changes in twins, the physiology of aging hematopoiesis, the pathogenesis of age-related hematopoietic malignancies and the clonality of cancers in human and nonhuman primates. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the liveweight gain of lambs, infected by multidrug-resistant nematodes, treated by conventional schemes of helminth control or using a schedule based on fecal egg count reduction test (FECRT). The flock was selected after a FECRT (experiment 1) which revealed a parasite population resistant to benzimidazoles, imidazothiazoles, macrocyclic lactones (ivermectin), salicylanilides, nitrophenols, and organophosphates. Despite the parasite resistance to ivermectin (an avermectin), the moxidectin (a milbemycin) was effective against the gastrointestinal nematodes (PR > 90 %). In experiment 2, 48 suckling lambs were distributed in four randomized blocks (G1, G2, G3, and G4) by previous body weighings. G1 was kept as untreated control; G2 was treated following a FECRT-based schedule with drugs chosen based on fecal analysis (first drench with moxidectin, second drench with a combination of moxidectin and levamisole, and third drench with praziquantel, an anti-cestode drug); G3 and G4 received three drenches with ivermectin or disophenol, respectively. Body weighings and fecal analysis of these lambs were performed every 2 weeks over a 98-day period. An effective control of gastrointestinal nematodes was obtained with two nematicidal drenches following the FECRT-based schedule of treatments. On the other hand, eggs per gram of feces (EPG) counts were no different among untreated control, G3, and G4. Lambs treated using the FECRT-based schedule had the greatest liveweight gain among the groups tested. Additionally, liveweight gain was no different among the groups G3, G4, and G1. The FECRT-based schedule of anthelmintic treatments was beneficial regarding productivity and sustainability of helminth control in lambs infected by multidrug-resistant nematodes. [ABSTRACT FROM AUTHOR]

Abstract: Sequential polymerizations were carried out using a high-activity MgCl2/Ziegler–Natta catalyst to evaluate whether the in situ preparation of polypropylene/1-butene alloys was possible inside the reaction vessel and analyze the effects of 1-butene on the final material properties. Propylene/1-butene alloy resins were synthesized in a sequential two-stage process. In the first stage, liquid pool propylene polymerizations were carried out in batch. In the second stage, 1-butene was polymerized inside the polypropylene matrix in gas-phase in semibatch mode. According to the obtained results, it is possible to incorporate 1-butene upon the polypropylene matrix inside the reactor at very low pressures, without affecting the properties of the continuous polypropylene matrix significantly. [Copyright &y& Elsevier]

Abstract: Batch liquid pool and semibatch gas-phase polymerizations were performed with high-activity Ziegler–Natta catalysts to evaluate the effect of 1-butene on the crystallinity, the melt temperature and the average molecular weights of the final 1-butene/propylene copolymers and alloys. According to the obtained results, 1-butene can be significantly incorporated into the polymer chain over the whole range of copolymer compositions in both gas and liquid-phases, leading to the decrease of the melting temperature of the copolymer resins. On the other hand, the properties of the polymer alloys seem to be less sensitive to 1-butene incorporation, indicating the development of a distinct 1-butene phase. The average molecular weights, the polydispersities and the reactivity ratios are quite different in the liquid pool and gas-phase processes, indicating that sorption/ diffusion effects may exert an important role during the copolymerization. The obtained reactivity ratios in the gas-phase are close to 1, while the reactivity ratios of propylene are systematically higher than the reactivity ratios of 1-butene in the liquid pool process. Polymer materials with large molecular weights and good particle morphology can be obtained in all analyzed cases, indicating that development of propylene/1-butene copolymer grades is indeed possible in both liquid pool and gas-phase processes. [Copyright &y& Elsevier]

Ethanol is the main biofuel produced by fermentation route and the search for new feedstocks to produce fuel ethanol is still a great challenge. This work aims to compare the ethanol production from a new irrigated rice cultivar BRS AG to the conventional cultivar BRS PAMPA applied in Brazil. Six different commercial strains of Saccharomyces cerevisiae (BG-1, CAT-1, FT-858, JP-1, PE-2, and SA-1) were applied in fermentation reactions. Fermentations performed with BRS PAMPA rice revealed that the highest yields were achieved with strain SA-1, corresponding to 93.0% of the theoretical maximum and final ethanol concentration of 58.92 g L−1, and with CAT-1, a yield of 92.7% and final ethanol concentration of 58.93 g L−1. For the fermentations with BRS AG rice, the highest yields were obtained with strain FT-858, exhibiting a 89.6% yield and final ethanol concentration of 62.45 g L−1, and with CAT-1, 87.9% yield and final ethanol concentration of 61.25 g L−1 were achieved. The most appropriate microorganism for ethanol production using BRS PAMPA rice and BRS AG rice was CAT-1. Comparatively, the ethanol yield and productivity using BRS AG were higher than those observed for BRS PAMPA for all strains, except for PE-2 and SA-1 that led to very similar results. The experimental results showed that the giant rice BRS AG is an excellent feedstock for fuel ethanol production in lowland fields. [ABSTRACT FROM AUTHOR]

Polycaprolactone is a biodegradable, biocompatible, and versatile polymer commonly used in the pharmaceutical and biomedical industry and the development of new catalysts that allow for the synthesis under milder reaction conditions and in shorter reaction times is an appealing alternative. The iron-containing imidazolium-based ionic liquid 1-n-butyl-3-methylimidazolium heptachlorodiferrate was able to efficiently catalyze the ring-opening polymerization of ε-caprolactone under mild reaction conditions. Polymerization yields higher than 80% were obtained after 4 h of reaction at temperatures up to 85 °C, using low ionic liquid:ε-caprolactone molar ratios (1:720 − 1:1500), in the absence of solvent and without an intentionally added alcohol as an initiator. Semi-crystalline polycaprolactones, with molecular weights up to 14 kDa and narrow molecular weight distributions were synthesized. The chemical structure of the polymer was confirmed by Nuclear Magnetic Resonance (1H NMR) and Fourier Transform Infrared (FTIR) spectroscopy, and its crystalline content was estimated from the enthalpy of melting of the differential scanning calorimetry (DSC) thermogram. Finally, a caprolactone-activated ROP mechanism mediated by the ionic liquid was suggested. [ABSTRACT FROM AUTHOR]

Dual-motor battery electric vehicles (DM-BEVs) are a trending technology in the electric vehicle market. They have the potential to achieve higher energy savings and dynamic performances compared to single-speed, single-motor BEVs. However, a more complex and robust energy management system (EMS) is needed to achieve these benefits. Hence, this work reviews the design process and real-time implementation of EMSs tailored for DM-BEVs, starting from the fundamental concepts of two-motor coupling. The advantages and disadvantages of the most popular dual-motor architectures and their influence on the EMS design complexity are presented, followed by a revision of the reported energy management controllers. Besides the most prominent methods, classified as rule-based or optimization-based techniques, reinforcement learning-based EMSs are discussed in detail, given their near-optimal, real-time implementation and adaptability to newer, unforeseen drive cycles. Finally, the standard procedures and equipment required to assess the EMS' performance with hardware-in-the-loop tests are presented. Conclusions and open challenges for the energy management controllers of DM-BEVs are discussed at the end of this work. [Display omitted] • The energy management design for dual-motor battery electric vehicles is explained. • Dual-motor architectures' influence on energy management complexity is discussed. • Existing and trending control approaches are presented. • The controller's migration for HIL and in-vehicle tests are explained. • Challenges and opportunities for dual-motor battery electric vehicles are listed. [ABSTRACT FROM AUTHOR]

This work reports the use of acrylated fatty acid methyl ester (AFAME) as a biomonomer for the synthesis of bio‐based hybrid magnetic particles poly(styrene‐co‐AFAME)/γ‐Fe2O3 produced by miniemulsion polymerization. Poly(styrene‐co‐AFAME)/γ‐Fe2O3 can be tailored for use in various fields by varying the content of AFAME. The strategy employed is to encapsulate superparamagnetic iron oxide nanoparticles (SPIONs) as γ‐Fe2O3 into a styrene/AFAME‐based copolymer matrix. Raman spectroscopy is employed to ensure the formation of the SPIONs (γ‐Fe2O3) obtained by a co‐precipitation technique followed by oxidation of Fe3O4. The functionalization of SPIONs with oleic acid (OA) is carried out to increase the SPIONs–monomer affinity. The presence of OA on the surface of γ‐Fe2O3 is certified by identification of main absorption bands by fourier‐transform infrared spectroscopy (FTIR). Thermal analysis (differential thermogravimetry/differential thermo analysis and differential scanning calorimetry) results of poly(styrene‐co‐AFAME)/γ‐Fe2O3 show an increase in AFAME content leading to a lower copolymer glass transition temperature (Tg). Dynamic light scattering (DLS) measurements result in poly(styrene‐co‐AFAME)/γ‐Fe2O3 particles with diameter in the range of 100–150 nm. It is also observed by transmission electron microscopy (TEM) and cryo‐TEM techniques that γ‐Fe2O3 particles are successfully encapsulated into the poly(styrene‐co‐AFAME) matrix. The biomonomer obtained from soybean oil (AFAME) is used for the synthesis of bio‐based hybrid magnetic particles, poly(styrene‐co‐AFAME)/γ‐Fe2O3, by miniemulsion polymerization. As a principal strategy, the superparamagnetic iron oxide nanoparticles γ‐Fe2O3 are encapsulated into styrene/acrylated fatty acid methyl ester (AFAME)‐based copolymer matrix. The properties of poly(styrene‐co‐AFAME)/γ‐Fe2O3 can be modulated depending on its use by varying the amount of AFAME. [ABSTRACT FROM AUTHOR]

• The review explores the world of functional chromophores synthesized via MCRs. • MCR-synthesized functional chromophores are reshaping imaging research. • Bioimaging probes synthesized by MCRs with tunable properties. This review aims to provide a comprehensive overview of recent advancements and applications of fluorescence imaging probes synthesized via MCRs (multicomponent reactions). These probes, also known as functional chromophores, belong to a currently investigated class of fluorophores that are presently being successfully applied in bioimaging experiments, especially in various living cell lineages. We describe some of the MCRs that have been employed in the synthesis of these probes and explore their applications in biological imaging, with an emphasis on cellular imaging. The review also discusses the challenges and future perspectives in the field, particularly considering the potential impact of MCR-based fluorescence imaging probes on advancing this field of research in the coming years. Considering that this area of research is relatively new and nearly a decade has passed since the first publication, this review also provides a historical perspective on this class of fluorophores, highlighting the pioneering works published between 2011 and 2016. [ABSTRACT FROM AUTHOR]

Gas phase copolymerizations of ethylene and an α‐olefin comonomer are performed using a commercial Ziegler–Natta catalyst in the presence of different induced condensing agents (ICA). The impact of these factors on the yield and final polyethylene properties such as the melt flow index, crystallinity, and incorporation of comonomer is studied. It has been shown that the increase in the rate of polymerization is even more pronounced in the presence of ICA. It also appears that adding ICA to the copolymerizations changes the comonomer incorporation with respect to similar copolymerizations performed without ICA due to competing cosolubility effects. [ABSTRACT FROM AUTHOR]

This work addresses a comparative study focused on the synthesis of alkyd resins from different renewable resources such as chia, castor and palm vegetable oils through the alcoholysis–polycondensation process. The formed alkyd resins are analyzed by Fourier transform infrared (FTIR), 1H NMR, and 13C NMR. Besides, intrinsic viscosity and gel permeation chromatography (GPC) assays are conducted to evaluate the differences between the obtained resins focusing on their molecular weight and physicochemical properties. FTIR shows a satisfactory conversion from vegetable oils to alkyd resins. Both 1H NMR and 13C NMR indicate that alkyd resins are successfully synthesized. The values for molecular‐weight dispersity (ÐM) obtained for the resins are 2.3, 1.3, and 1.7 from chia, palm, and crude castor, along with the weight‐average molecular weight (Mw) of 4516, 1025, and 2451 g mol−1, respectively. The chia alkyd resin shows a 571.92 cP and is the highest viscosity obtained. It is also observed that an increase in phthalic anhydride can increase the molecular weight of the alkyd resin. This comparative study indicates that chia oil alkyd resin has enormous potential to be employed as a surface coating agent. [ABSTRACT FROM AUTHOR]

Graphical abstract A biobased monomer acrylated ricinoleic acid was synthesized from castor oil and copolymerized with methyl methacrylate in miniemulsion forming polymeric nanoparticles. The addition of the biobased monomer led to a decrease in the glass transition temperature of the copolymer and to the formation of a small fraction of gel, resulting in materials with interesting properties for future applications. Highlights • A biobased monomer acrylated ricinoleic acid was synthesized from castor oil. • The biobased monomer was copolymerized with methyl methacrylate in miniemulsion forming polymeric nanoparticles. • Polymers with lower Tgs were obtained with the addition of the biobased monomer. • The copolymers exhibited interesting properties for future applications as adhesives. Abstract Vegetable oils-based polymers are promising materials with application in the industry of coatings and adhesives. Chemically-modified ricinoleic acid obtained from castor oil was used in this study to produce polymeric materials. The adopted strategy consisted in the epoxidation of the double bonds of ricinoleic acid, followed by the ring opening reaction in the presence of acrylic acid to form the acrylated ricinoleic acid (ARA). Free radical copolymerizations of ARA and methyl methacrylate (MMA) were carried out in miniemulsion, resulting in latexes stable over a long storage time. DLS measurements revealed the formation of submicron polymeric particles of different sizes strongly dependent on the fraction of the biobased monomer ARA, exhibiting diameters ranging from approximately 80 nm to 150 nm, as the ARA fraction was increased up to 80 wt%. It was possible to prepare polymers with broad ranges of mass-average molar masses in the range from 1137 kDa to 65 kDa and glass transition temperatures lying in the interval from approximately 124 °C–50 °C by varying the concentration of the comonomer ARA. Crosslinked copolymers were obtained by increasing the proportion of ARA. [ABSTRACT FROM AUTHOR]

To optimize a benchmark commercial dishwashing formulation, this paper presents a fractional factorial design procedure coupled with a mixture design in order to obtain a formulation with better properties and cost, as well as to provide an example of quick formula optimization that may also be useful for other cleaning and personal hygiene sectors. First, a fractional factorial design was performed to determine the significant effects for each response variable: viscosity, performance, foaming, and Krafft temperature. Then, a mixture design was used to determine the compositions that feature the best results for each property of interest. The determined compositions that meet the requirements with 90-95% confidence showed that improvements in the compositions can be adopted. It was possible to estimate compositions based on commercial formulations that meet the same cost per kilogram of product but with gains in detergency, foaming, and viscosity volume. [ABSTRACT FROM AUTHOR]

The development of more sustainable materials from renewable resources has increasingly gained attention. In this work, commercial limonene oxide was used as a monomer to obtain polyesters with phthalic and maleic anhydrides. The ionic liquid 1-n-butyl-3-methylimidazolium heptachlorodiferrate (BMI·Fe2Cl7) was the catalyst for ring-opening polymerization. For both cyclic anhydrides, conversions around 80% were reached with a 1:100 catalyst:limonene oxide molar ratio. The resulting polymers presented a perfectly alternating structure, number-average molar mass over 1000 g mol−1, and pendant double-bonds that allow subsequent modification of their structures. Regarding their application, such as nanodevices for biological systems, poly(phthalic anhydride-co-limonene oxide) (PPALO) nanoparticles (NPs) were also produced and cross-linked with tetrathiol via thiol-ene reaction. The cross-linked PPALO-NPs with a number-weighted mean diameter of 56 nm, spherical morphology, and good colloidal stability were obtained. These NPs were tested for blood compatibility with human red blood (erythrocytes) cells and cell viability using mouse embryo fibroblast (NIH3T3) cell line, presenting potential for biomedical applications. [ABSTRACT FROM AUTHOR]

The trypanosome life cycle consists of a series of developmental forms each adapted to an environment in the relevant insect and/or mammalian host. The differentiation process from the mammalian bloodstream form to the insect-midgut procyclic form in Trypanosoma brucei occurs in two steps in vivo . First proliferating ‘slender' bloodstream forms differentiate to non-dividing ‘stumpy' forms arrested in G1. Second, in response to environmental cues, stumpy bloodstream forms re-enter the cell cycle and start to proliferate as procyclic forms after a lag during which both cell morphology and gene expression are modified. Nearly all arrested cells have lower rates of protein synthesis when compared to the proliferating equivalent. In eukaryotes, one mechanism used to regulate the overall rate of protein synthesis involves phosphorylation of the alpha subunit of initiation factor eIF2 (eIF2α). The effect of eIF2α phosphorylation is to prevent the action of eIF2B, the guanine nucleotide exchange factor that activates eIF2 for the next rounds of initiation. To investigate the role of the phosphorylation of eIF2α in the life cycle of T. brucei , a cell line was made with a single eIF2α gene that contained the phosphorylation site, threonine 169, mutated to alanine. These cells were capable of differentiating from proliferating bloodstream form cells into arrested stumpy forms in mice and into procyclic forms in vitro and in tsetse flies. These results indicate that translation attenuation mediated by the phosphorylation of eIF2α on threonine 169 is not necessary for the cell cycle arrest associated with these differentiation processes. [ABSTRACT FROM AUTHOR]

This work presents an experimental study focusing on the preparation and characterization of modified green clay with quaternary ammonium salts alkyl dimethyl benzyl ammonium chloride (ADMBAC) and distearyl dimethyl ammonium chloride (DSDMAC) intended to be used as adsorbent in the process of removing oil emulsion in an oil–water system using finite bath. X-ray diffraction (XRD), infrared spectroscopy (IR) and expansion test (adsorption capacity and Foster swelling) measurements were performed in order to evaluate the performance of the ion exchange reactions and the degree of affinity with oil products. There was an increase in the XRD basal spacing of the modified clays (1.96 nm and 2.25 nm for DSDMAC and ADMBAC salts, respectively) in comparison to the observed value (1.56 nm) for the unmodified clay. The IR results revealed that salts were successfully incorporated to clay structure. Based on the expansion tests the organoclays presented the best efficiency of separation, independent on the kind of solvent used in comparison with the unmodified clay performance. The modified clays exhibit a very high capacity of adsorption. The predictions of multiple linear regression models determined based on the factorial design of experiments are excellent. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel electrochemical sensor for dopamine detection was successfully developed. • The IL terpolymer/iron oxide/MWCNT electrode displayed a great synergistic response. • Dopamine was detected in the presence of a 25-fold excess of ascorbic acid. • After 80 runs TS-MAG-MWCNT electrode showed only an 8% reduction in its sensitivity. • Sensor response is not affected by the matrix composition or other interferents. In this study, we introduce a novel electrochemical sensor for dopamine (DA) detection utilizing an ionic liquid-based terpolymer/iron oxide/multiwalled carbon nanotube (TS-MAG-MWCNT) nanocomposite electrode. The synergistic combination of improved surface adhesion, electrocatalytic activity, and electron conductivity of each individual material enables the determination of DA in the presence of a 25-fold excess of AA (ascorbic acid). The electrode, operated by square wave voltammetry, allows the detection of DA within a wide linear working range from 1 µmol/L to 200 µmol/L, with a limit of detection of 63 nmol/L. A single TS-MAG-MWCNT electrode can be used for more than 80 consecutive runs, with only an 8 % reduction in its sensitivity. Additionally, the response of electrodes fabricated in different batches varies by only 5 %. The sensor's response is not affected by the matrix composition or other interferents, as demonstrated by experiments conducted in synthetic urine. [ABSTRACT FROM AUTHOR]

Poly(vinyl pivalate) (PVPi) nanoparticles obtained via miniemulsion have particular properties useful for several applications. Thus, the present study aims to synthesize and characterize PVPi nanoparticles through the miniemulsion polymerization process, studying the effects of water‐soluble and oil‐soluble initiators, polymerization temperature, and the co‐stabilizer concentration on the final properties of the polymer, nanoparticle size, and conversion. The polymeric nanoparticles are characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance (1H and 13C NMR), thermogravimetric analysis, differential scanning calorimetry, gel permeation chromatography, dynamic light scattering, and transmission electron microscopy. The miniemulsion polymerization process ensures the formation of a polymeric fluid with high colloidal and thermal stability, with maximum conversions of ≈85% and average particle diameter of 97.2 ± 21.8 nm. The polymeric properties, such as molar mass and glass transition temperature (Tg), are influenced by process variables such as synthesis temperature and the type of initiator. The use of potassium persulfate and 2,2‐azobisisobutyronitrile (AIBN) initiators favors the homogeneous nucleation mechanism, resulting in a decrease in the average particle diameter and in the growth of the chains, result in greater average molar masses and, consequently, greater Tg. [ABSTRACT FROM AUTHOR]

Molecularly imprinted polymers (MIP) are known as high selective sorbent, however, its application in aqueous medium is very limiting. In this way, a new hybrid MIP was successfully synthesized for saccharin (SAC) extraction in aqueous medium. SAC determination in surface waters becomes a challenge due to high dissipation that results in low concentration and susceptibility to potential interferences. Two polymer materials synthesized through bulk (HMIP-B) and suspension (HMIP-S) polymerizations were studied, and its performance has been compared according to morphological, adsorption isotherms, thermodynamics, and selectivity properties. The adsorption process was thermodynamically favorable and adsorption capacities (qe) were 1.24 and 4.32 mg g-1 for HMIP-B and HMIP-S, respectively. The material was characterized as heterogeneous with two binding sites fitted by Langmuir–Freundlich model and pseudo-second-order model. The imprinting factor (IF) was 4.8 for both materials and the HMIP-S presented superior results in selectivity, with a distribution constant (Kd) value of 12.1 times higher than HMIP-B for saccharin and a selectivity coefficient (k) of 7.73, 9.25 and 2.54 for acesulfame, caffeine and cyclamate, respectively. The selecitivity of HMIP in aqueous medium was tested in surface water samples, resulting in 89% of SAC recovery. [ABSTRACT FROM AUTHOR]

• Gold nanoparticles functionalized with a novel poly(ionic liquid). • The poly(ionic liquid) replaces citrate ions and provides for better colloidal stability of the gold nanoparticles. • Gold nanoparticles-poly(ionic liquid) layer-by-layer assembled nanocomposite enhances the electrocatalytic activity of ITO electrode towards triclosan electro oxidation. • Triclosan is detected at very low concentrations at both tooth paste and lake water samples. • The voltammetric method based on gold nanoparticles-poly(ionic liquid) nanocomposite electrode is insensitive to the matrix effect. Triclosan (TCS), a powerful bactericide agent found in personal care products, has been recently recognized as a contaminant of emerging concern, with endocrine disrupting chemical activity, and whose detection in environmental, biological and/or PCP samples is of great concern nowadays. Therefore, this contribution describes indium-doped tin oxide (ITO) substrates modified with Au nanoparticle-poly(ionic liquid) (Au-PIL) nanocomposite films for the voltammetric detection of TCS in lake water and toothpaste samples. The electroanalytical performance evaluated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV), shows the modified electrode oxidizes TCS at much higher oxidation currents than bare ITO. At optimized conditions, the analytical method is linear (R2 > 0.99) in the selected working range (10–60 µmol L−1), presents a sensitivity of 57.1 µA cm−2/mol L−1•and a limit of detection of 0.098 µmol L−1 (28.3 µg L−1). TCS determinations are successfully carried out in spiked lake water samples showing that the electrode response is not affected by such a complex matrix. The concentration of TCS found in a commercial brand toothpaste, simultaneously determined by voltammetry and HPLC, is similar (95% confidence level, t -test) between both techniques and comparable to that described in the product package. [ABSTRACT FROM AUTHOR]

Abstract This work provides details regarding the physicochemical, antimicrobial and antioxidant properties of poly(vinyl chloride) (PVC)-based films containing 0.4% quercetin and silver nanoparticles (AgNPs) at various concentrations levels. The incorporation of quercetin and AgNPs into the PVC matrix considerably affected the thermal, mechanical and optical properties of the films. Results obtained from the tensile stresgth test, demonstrated an improvement in the mechanical strength of the films after the incorporation of both quercetin and AgNPs. Moreover, an increase in AgNPs concentration increased the rigidity, as compared to control PVC film. Antimicrobial activity against food pathogens (Escherichia coli , Salmonella Typhimurium and Listeria monocytogenes) was evaluated by an antimicrobial barrier test. Results showed that the PVC-based films with quercetin and AgNPs proved to be highly effective to inhibiting bacterial growth. Therefore, these results indicate promising evidence to possibly aid in the prevention of microbial dissemination in foods. Additionally, films incorporated with quercetin and AgNPs expressed an antioxidant capacity when evaluated via the DPPH method. Among all of the films evaluated, the PVC-based films containing 0.4% quercetin and 1% AgNPs were flexible, exhibiting excellent UV-light barrier properties and for use with fatty foods, with the intent of reducing lipid oxidation and preventing food pathogen dissemination. Highlights • The antioxidant and antimicrobial films are suitable for fatty foods. • PVC-based film with AgNPs and Quercetin lead to improvement on mechanical strength. • PVC films showed adequate transparency and significant UV barrier. • Q-AgNPs films were able to reduce the lipid oxidation and bacterial inhibition. [ABSTRACT FROM AUTHOR]

Poly(vinyl pivalate) − PVPi is a poly(vinyl ester) that presents interesting characteristics that lead to the production of embolic agents, such as poly(vinyl alcohol) (PVA), with high level of sindiotacticity in contrast to the one synthesized from poly(vinyl acetate), for example. This work aims the study of the influence of process variables, such as stirring speed, amount of initiator, and suspending agent concentration on the suspension polymerization reaction of vinyl pivalate. Also, it has the objective of studying the way these parameters can influence the properties of the polymeric particles formation. For this purpose, the reaction system was evaluated using 550, 750, 950, and 1150 rpm as stirring speed, fraction of initiator in the range from 0.3 to 0.5 wt.%, and 0.5, 1.0, 1.5, 2.0, and 2.5 g L−1 of suspending agent. All samples were characterized by classical gravimetric measurements, proton nuclear magnetic resonance (1H‐NMR), gel permeation chromatography (GPC), and scanning electron microscopy (SEM). 1H‐NMR measurements confirmed the synthesis of poly(vinyl pivalate). SEM images have suggested the formation of particles with spherical morphology, exhibiting average diameters of 200, 122, 86, and 79 µm related to the stirring speed of 550, 750, 950 e 1150 rpm, respectively. It was also observed that the polymers had average molar mass of 6.7 · 105, 4.8 · 105, and 4.4 · 105 g mol−1 when 0.3, 0.4, and 0.5 wt.% of benzoyl peroxide (BPO) was employed, respectively. The global conversion achieved was ca. 90% in all conditions. [ABSTRACT FROM AUTHOR]

For the first time, it was shown the cationic miniemulsion polymerization of styrene using an ionic liquid as catalyst. The ionic liquid (BMI·Fe 2 Cl 7 ) was tolerant to the presence of high amount of water, being effective for polymerization of styrene in the evaluated temperatures range from 70 to 90 °C. The polymerization was considerably slower than conventional cationic polymerization, indicating that this process is easier to control than the conventional ones. In addition, quite high molecular weights were reached, while the particle size, between 150 and 175 nm, was within the typical range for miniemulsion polymerization. [ABSTRACT FROM AUTHOR]

Nanoparticles of iron oxide play an important role on the field of nanotechnology and nanoscience presenting tremendous potential for various applications. Oleic acid has been shown to be a promising coating material, allowing to obtain monodisperse, uniform and stable nanoparticles. However, for certain applications which utilize the encapsulation of magnetic nanoparticles into polymer matrices it becomes necessary to use coating materials which exhibit functional groups in their structure capable of avoiding leaching problems. To this end, the present study aimed to develop magnetite nanoparticles coated with chemically modified oleic acid. The reactive functional group present in the fatty acid molecule can promote polymerization between the monomer species and the coating material with high encapsulation efficiency. The different steps of the reactions to obtain acrylated oleic acid were evaluated by Fourier transform infrared (FTIR) spectroscopy and 1 H nuclear magnetic resonance spectroscopy. The coated nanoparticles were characterized by FTIR, thermogravimetric analysis, X-ray diffraction, transmission electron microscopy, Mössbauer spectroscopy, Raman spectroscopy and magnetization measurements. The coated nanoparticles showed high dispersibility with a uniform average size of 9.5 nm, saturation magnetization of 61.2 emu/g and superparamagnetic behavior, which make it a very promising for the formation of nanocomposites. [ABSTRACT FROM AUTHOR]

This work presents a new biobased poly(urethane-ester) synthesized from ricinoleic acid (RA), 1,6-diisocyanatehexane, and glycerol through bulk polymerization. RA-modified magnetic iron oxide nanoparticles, previously obtained through coprecipitation technique, were introduced in situ to produce a magnetic nanocomposite. DSC analyses revealed that the glass transition (Tg) of the biobased poly(urethane-ester) was equal to −75°C, and for the magnetic biobased poly(urethane-ester) the Tg was reduced in approximately 3°C. DTG analyses were used to measure the thermal stability and the amount of magnetic nanoparticle dispersed into the polymeric matrix, indicating that the polymeric materials exhibit good thermal stability and the fraction of nanoparticles dispersed into the biobased poly(urethane-ester) matrix was equal to 2.19 wt%. Infrared spectroscopy and NMR were used to recognize functional groups in structures and follow the reaction evolution. Magnetic force, hysteresis loops and XRD essays used to provide magnetic features of the materials, showed that crystallite size of the mono domains was equal to 7.6 nm and that magnetic materials exhibit superparamagnetic behavior. GPC was used to evaluate average molar mass of polymer, determined equal to 2569 Da and molar mass dispersity equal to 2.4. Practical applications: Introducing magnetic nanoparticles into polymeric matrix leads to composites with unique properties, allowing different applications. Besides, the use of vegetable oils to produce polymer has many advantages such as biocompatibility and renewability. Due to their physico-chemical and biocompatibility properties the magnetic nanocomposites using castor bean oil prepared in the present work may have potential candidates for several applications, like biomedical implants, tissue engineering, and controlled drug delivery. This article describes the preparation of a new biobased poly(urethane-ester) synthesized from ricinoleic acid (RA), 1,6-diisocyanatehexane, and glycerol and its use as polymeric matrix in magnetic nanocomposite. The polymer is characterized by FTIR, 1H NMR, TG, and DSC. The composite is studied by magnetic force exhibiting superparamagnetic behavior. [ABSTRACT FROM AUTHOR]

The present work addresses the use of Raman spectroscopy and multivariate curve resolution–alternating least squares (MCR-ALS) for the evaluation of the reaction conversion in copolymerization of aluminum (III) methacrylate and vinyl monomers (vinyl acetate, ethyl acrylate and methyl methacrylate). For the synthesis of these materials, pseudo-dispersion copolymerizations were carried out in a reaction medium containing 17 wt.% of aluminum (III) methacrylate [Al(III)MA] and 83 wt.% of vinyl monomers, such as vinyl acetate (VAc), ethyl acrylate (EA) and methyl methacrylate (MMA). Raman spectra were acquired at different reaction times for each monomer used. We used multivariate curve resolution (MCR-ALS) in order to evaluate the reaction conversion and the concentration profiles. The concentration profile of VAc/Al(III)MA reaction shows that the polymerization occurs slowly, in which the conversion stabilizes after 15 h of reaction. The concentration profile of EA/Al(III)MA copolymerization shows that high conversions are achieved in a short reaction time. However, as the reaction proceeds (between 4 and 12 h), it is possible to observe a decrease of the reaction rate, which is an indication that the modified monomer is polymerizing. The concentration profile of MMA/Al(III)MA copolymerization shows a high conversion in the first 2 h of reaction, indicating a possible low incorporation of the modified metal monomer into the growing copolymer chains, due to the differences of reactivity between the monomer species. The use of Raman spectroscopy coupled with MCR-ALS allowed for the evaluation of the conversion rate of three different organic–inorganic copolymers, although it is difficult to determine the conversion of hybrid polymers, the use of chemometric methods and Raman spectroscopy allowed us to compare the conversion rate between the studied copolymers. [ABSTRACT FROM AUTHOR]

This work presents experimental results on the synthesis of soybean oil-based polymers through emulsion polymerization process. It was shown that polymeric materials can be successfully synthesized with high monomers conversion close to 100% and very high stability, displaying relatively high shelf-life time. Polymeric nanoparticles showing narrow particle size distribution, with average diameter around 80 nm (PdI = 0.213), determined via dynamic light scattering measurements were obtained. It was also observed by calorimetric analysis, that the final polymeric material presents two exothermic transitions and two glass transition temperatures. This complex thermal behavior probably takes place due to the nature of the monomeric mixture (AFFAM—acrylated linolenic, linoleic, and oleic acids in combination with methyl methacrylate), indicating that the final polymer presents a complex macromolecular arrangement. The glass transition temperature of the polymer lattices was reduced because of the AFFAM incorporation into the growing polymer chains, and additionally the thermal stability was improved. Regarding the average molar masses, it was observed that AFFAM comonomer plays an important role, leading to a decreasing in the mass-average molar mass when the AFFAM concentration is increased in the reaction medium. Depending on the AFFAM amount, the mass-average molar masses were found within the range from 70,000 g mol −1 to 890,000 g mol −1 with molar-mass dispersity lying in the interval from 1.7 to 2.4. [ABSTRACT FROM AUTHOR]

In this work, the emulsion copolymerization of styrene and acrylated methyl oleate (AMO), a monomer derived from oleic acid (OA), has been evaluated. Reactions exhibiting high monomers conversions were successfully performed, leading to the formation of very stable polymer lattices, whose average particle size is kept unchanged for relatively high storage times. The average molar masses determined by gel permeation chromatography showed to be very dependent on the amount of AMO in the reaction medium, presenting experimental values within the range from 280 000 to 39 000 g mol−1 with molar mass dispersity ranging from 4 to 2 when the AMO fraction in the reaction medium was increased to 40 wt%. The nucleation rate was affected by AMO in such way that an increase in AMO concentration must be accompanied by an increase in initiator concentration, which leads to the reduction of the average molar masses of the copolymer. The thermal analyses of the polymer materials showed that the glass transition temperature decreased with increasing amount of AMO in the copolymer chains. Practical applications: The use of vegetable oils and their derivatives as precursor monomers in polymerization reactions has increased each day due to their renewable origin. Among them, OA deserves special attention due to the high availability and ease of chemical modification, mainly when the double bounds are considered. Results showed that AMO could be incorporated at high ratios in emulsion polymerization reducing the glass transition temperatures of the copolymer. The polymer lattices also showed good storage stability. [ABSTRACT FROM AUTHOR]

Abstract: This work provides details on the synthesis of poly(vinyl acetate)/poly(vinyl alcohol) intended for medical applications such as intravascular embolization procedures and hyperthermia treatment of injured areas. The proposed method showed to be very efficient for the synthesis of micro-sized magnetic particles. The hydrolyzed polymeric material presented thermal stability higher than that observed in pure poly(vinyl acetate) particle and the magnetic polymeric materials exhibited better thermal stability. It was also shown that the morphology of the precursor poly(vinyl acetate) is preserved when mild reaction conditions (temperature and alkoxide concentration) are adopted during the hydrolysis reaction. Furthermore, it was noticed that Na2SO4 promotes morphological control, minimizing the solubility of poly(vinyl acetate) in methanol and poly(vinyl alcohol) in water. DSC analyses showed that polymer particles with core–shell type morphology were properly obtained, exhibiting two distinct glass transition temperatures, characterized by the presence of pure poly(vinyl alcohol) in the shell and pure poly(vinyl acetate) in the core of the particles. [Copyright &y& Elsevier]

The electrostatic dehydration of crude-oil emulsionswere investigatedusing pilot-plant and industrial data. The experimental data obtainedwith seven different crudes over a wide range of viscosities in apilot plant showed that the electric field and the residence timewere the most important operating variables. Various crude-oil propertiesinfluenced the emulsion stability, including the total acid numberand the resin, asphaltene, and metal contents, but their effects werestatistically correlated with the crude-oil viscosity and density.Using pilot-plant data, a power-law model relating the water contentin the treated oil to the dehydration operating conditions and thecrude-oil viscosity and density was developed to aid in the designand evaluation of industrial units. The model was tested against industrialdata and found to be able to predict very well the performance ofthe industrial units. [ABSTRACT FROM AUTHOR]

Enzymatically synthesised poly(glycerol adipate) (PGA) has shown a palette of key desirable properties required for a biomaterial to be considered a 'versatile polymeric tool' in the field of drug delivery. PGA and its variations can self-assemble into nanoparticles (NPs) and interact at different levels with small active molecules. PGA derivatives are usually obtained by functionalising the glyceryl side hydroxyl group present along the main polymer scaffold. However, if the synthetic pathways are not finely tuned, the self-assembling ability of these new polymeric modifications might be hampered by the poor amphiphilic balance. For this reason, we have designed a straightforward one-pot synthetic modification, using a small library of diols in combination with glycerol, aimed at altering the backbone of the polymer without affecting the hydrophilic glyceryl portion. The diols introduce additional functionality into the backbone of PGA alongside the secondary hydroxyl group already present. We have investigated how extra functionalities along the polymer backbone alter the final polymer reactivity as well the chemical and biological properties of the nanoparticles. In addition, with the intent to further improve the green credentials of the enzymatic synthesis, a solvent derived from renewable resources, (2-methyl tetrahydrofuran, 2-MeTHF) was employed for the synthesis of all the PGA-variants as a replacement for the more traditionally used and fossil-based tetrahydrofuran (THF). In vitro assays carried out to evaluate the potential of these novel materials for drug delivery applications demonstrated very low cytotoxicity characteristic against NIH 3T3 model cell line. [Display omitted] • Poly(glycerol adipate) (PGA) one-pot synthetic alteration using a series of diols. • Direct modification of the PGA backbone without affecting the glyceryl portion. • The diols used have introduced additional functionality into the backbone. • A renewably sourced solvent, (2-MeTHF) was employed for the polymer synthesis. [ABSTRACT FROM AUTHOR]

Eng. 2/2021 This is reported by Weslany Neto, Gabriel Dutra, Leonardo Valadares, Fernando Souza Jr, Marcelo Sousa, and Fabricio Machado in article 2000049. B Front Cover b : The production of highly stable poly(vinyl pivalate) latex has been evaluated in a miniemulsion polymerization process, focusing on the effect of the main operating process variables such as polymerization temperature, co-stabilizer concentration, and water-soluble and oil-soluble initiators on the final properties of the polymer, nanoparticle size and monomer conversion. [Extracted from the article]

The objective of this work is to develop and characterize polymeric nanoparticles with core–shell morphology through miniemulsion polymerization combined with seeded emulsion polymerization, aiming at the application in the treatment of vascular tumors via intravascular embolization. The synthesis of the core–shell nanocomposites was divided into two main steps: (i) Formation of the core structure, consisting of poly(methyl methacrylate)/magnetic oxide coated with oleic acid (OM-OA) via miniemulsion and (ii) shell structure produced through seeded emulsion polymerization of vinyl pivalate. Nanocomposites containing about 8 wt.% of OM-OA showed high colloidal stability, mean diameter of 216.8 nm, spherical morphology, saturation magnetization (Ms) of 4.65 emu·g−1 (57.41 emu·g−1 of Fe3O4), preserved superparamagnetic behavior and glass transition temperature (Tg) of 111.8 °C. TEM micrographs confirmed the obtaining of uniformly dispersed magnetic nanoparticles in the PMMA and that the core–shell structure was obtained by seeded emulsion with Ms of 1.35 emu·g−1 (56.25 emu·g−1 of Fe3O4) and Tg of 114.7 °C. In vitro cytotoxicity assays against murine tumor of melanoma (B16F10) and human Keratinocytes (HaCaT) cell lines were carried out showing that the core–shell magnetic polymeric materials (a core, consisting of poly(methyl methacrylate)/Fe3O4 and, a shell, formed by poly(vinyl pivalate)) presented high cell viabilities for both murine melanoma tumor cell lines, B16F10, and human keratinocyte cells, HaCaT. [ABSTRACT FROM AUTHOR]

The ionic liquid 1‐n‐butyl‐3‐methylimidazolium heptachlorodiferrate (BMI.Fe2Cl7) is efficiently used as catalyst in the cationic emulsion polymerization of styrene. The effect of different reaction temperatures, surfactant, and ionic liquid concentrations on polymer properties as molecular weight distribution and particle size is evaluated. High weight average molecular weights, above 1000 kDa, are achieved at 70% of conversion in 100 nm polystyrene particles formed mainly by micellar nucleation. Particle sizes and molecular weights increase with the decrease of the amount of surfactant. Even at low concentrations, BMI.Fe2Cl7/styrene molar ratio equal to 1/1000, the ionic liquid proves to be efficient for the emulsion polymerization of styrene, and lower ionic liquid concentrations lead to the formation of longer polymer chains. [ABSTRACT FROM AUTHOR]