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Several commercial silicas were used to support metallocene active centres, and the resulting precatalysts were used to study the impact of the pore size and pore size distribution of the support on the polymerization kinetics and resulting polymer properties. Pore volume distribution played a major role in the fragmentation of silica‐supported catalysts, where mesoporous silicas with a narrow distribution in the region obtained higher activities and faster fragmentation than silicas with a broad pore volume distribution. Therefore, it is shown that care must be taken when using standard information on particle porosity, as this quantity can be misleading. It appears that the minimum pore size, particularly on the particle surface, can be a very important parameter even if it does not impact the estimate of the porosity. [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]

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]

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]

This work focuses on increasing the solids content of water‐based coating materials such as paints, other coatings or adhesives while attempting to reduce the amount of surfactant in the final latex. The synthesis of a latex with a bimodal particle size distribution was carried out by combining RAFT and classical emulsion polymerization processes. By employing the RAFT polymerization, the population of small particles was created by self‐ordering the block copolymer chains, consisting of a hydrophilic block based on methacrylic acid or sodium 4‐styrenesulfonate and another hydrophobic block based on styrene. The final latex was made by adding a pre‐emulsion prepared from the latex of small particles and a mixture of monomers and surfactants to the latex of large particles made via conventional emulsion polymerization. The final bimodal latex thus obtained had a solids content of 65% mass with a viscosity value of around 2.0 Pa.s at a shear rate of 20 s−1. [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]

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]

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]

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]

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]

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]

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]

In this study, we synthesized a new class of copolymeric lattices based on vinyl pivalate (VPi) and modified oleic acid (OA) through a batch emulsion polymerization process. The effects of the chemically modified OA [methacrylated methyl oleate (MAMO)] on the thermal stability, glass‐transition temperature (Tg), average molar masses [mass‐average molar mass (Mw) and number‐average molar mass (Mn)], and molar mass dispersity (Ð) of the copolymers were evaluated. The experimental results indicate that via the introduction of MAMO into the polymer chains resulted in significant reductions in Tg, Mw, Mn, and Ð; this demonstrated a decrease of Tg at approximately 40 °C when the MAMO molar fraction equaled 9% compared to the value observed for the pure poly(vinyl pivalate) (PVPi), which was equal to 80.5 °C. MAMO incorporation led to a significant decrease in the Mw value observed in the interval, with a differential from approximately 1.6 × 103 to 289.6 kg/mol, and Ð values between 2.17 to 1.55, which was when the MAMO molar fraction present in the VPi‐containing copolymers varied from zero (pure PVPi) to approximately 9 mol %. We also observed that the thermal stability of the copolymers decreased slightly when the MAMO concentration increased in the reaction medium. Despite this minor drawback, polymer lattices with a high colloidal stability were formed at a high rate of polymerization, and the elevated conversion was within the interval 90–100%. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44129. [ABSTRACT FROM AUTHOR]

This work focuses on the synthesis of a new class of copolymer materials consisting of traditional vinyl monomers (essentially, vinyl acetate, ethyl acrylate, and methyl methacrylate) and copper (II) methacrylate (Cu(II)MA) intended to be used as surface modification agents in electrochemical quantifications of organic and inorganic analytes. Voltammetry assays showed that when deposited on glassy-carbon electrode (GCE), Cu(II)MA-based copolymers are very promising materials to be applied in electrochemical determinations, exhibiting high analytical signal in the oxidation and reduction peaks during quantification of potassium hexacyanoferrate (III) in comparison to a bare GCE, contributing to increase the effective electrode area. When employed for the determination of ascorbic acid, PVAcCu(II)MA/GCE exhibited performance similar to that of the bare GCE. Polymers characterizations showed that glass transition temperature of the Cu(II)MA-based materials increased in approximately 10-20°C, as consequence of the copper present in molecular structure of the copolymer chains (bidentate bridging coordination mode). Energy-dispersive X-ray spectroscopy measurements of Cu(II)MA monomer and Cu(II)MA-based copolymers showed strong characteristic peaks K&#945 and Kβ at 8.04 and 8.90 keV, respectively, with an average amount of copper of 99%. The performance of the Cu(II)MA-based copolymers modified electrodes is strongly dependent on the amount of copper into the copolymer chains and consequently on the monomers conversion. [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 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]

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]