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The study aimed to evaluate the impact of two chain transfer controllers, ethyl 2-(phenylcarbonothiolthio)-2-phenylacetate (EPPA) and 2-(4-methoxyphenylcarbonothiolthio) ethanoic acid (MPEA), from the dithioester family (dithiobenzoates), on the RAFT polymerization of β-myrcene. The initiators employed were azobisisobutyronitrile (AIBN) or dicumylperoxide (DCP), at 65 °C and 90 °C, respectively. The study analyzed the impact of the type of controller, temperature, and initiator/controller ratio on the living nature of β-myrcene polymerization. The results showed that with an increase in the initiator/controller ratio, the rate of polymerization increased, but the obtained molar masses decreased. The MPEA controller showed better performance in controlling the termination and chain transfer reactions, especially when AIBN was used as the initiator. A rise in polymerization temperature led to a loss in the control of polymerization, causing an increase in the degree of polydispersity due to the presence of transfer reactions. The most effective control in the RAFT polymerization of β-myrcene was achieved using MPEA as the controller and AIBN as the initiator, resulting in a poly(β-myrcene) with 87% 1,4-addition according to proton NMR analyses and a polydispersity of 1.27 by gel permeation chromatography (GPC). Finally, the study synthesized a poly(β-myrcene)-b-poly(styrene) block copolymer with low polydispersity (Ð1.1) by sequentially adding styrene to the previously synthesized MPEA-poly(β-myrcene)-based RAFT macrocontroller. [ABSTRACT FROM AUTHOR]

In this research, we explored the synthesis and application of thiolactone acrylamide (TLA) polymers for neutralizing reactive oxygen species (ROS), produced as a result of traumatic brain injury (TBI). We synthesized well‐defined TLA polymers using RAFT (reversible addition‐fragmentation chain transfer) polymerization across a range of monomer‐to‐chain transfer agent ([M]0/[CTA]0) ratios to achieve a range of molar masses. Polymerizations were carried out using a trithiocarbonate CTA (chain transfer agent) with AIBN (azobisisobutyronitrile) as the initiator in N'N‐dimethylacetamide (DMAc) at 60 °C. Kinetic studies indicated a linear increase in molar mass with conversion, pseudo‐first‐order kinetics, and molar mass values that are consistent with theoretical predictions. Furthermore, the polymerizations exhibited a decrease in molar mass dispersity with conversion. We then investigated ring opening of the thiolactone residues with isoserinol (ISOH), which was followed by thiol‐ene reactions of the resultant thiol groups with methacrylamide to yield a series of copolymers with different thiol‐to‐thioether ratios. The resulting polymers demonstrated varying levels of ROS neutralization. Higher thiol concentrations lead to more rapid neutralization while thioether residues provided sustained neutralization activity. [ABSTRACT FROM AUTHOR]

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We synthesized polymer-encapsulated pigments with excellent properties by using only one monomer, such as 2-hydroxyethyl acrylate (HEA). The polymer-encapsulated pigments were synthesized by emulsion polymerization with aqueous dispersions of the pigments (C.I. pigment red 112, C.I. pigment blue 15:3, or C.I. pigment yellow 155), monomers (2-hydroxyethyl acrylate, 4-methylstyrene, alpha-methylstyrene, styrene, or butyl acrylate), and an initiator (potassium persulfate or azobisisobutyronitrile). We discussed the core–shell particles (polymer-encapsulated pigments) with a morphology map of the polymer–pigment system. The polymer-encapsulated pigments were used to dye nylon 6, polyester, and cotton. The polymer-encapsulated pigments had particle sizes of less than 200 nm and excellent ratings for dry rubbing fastness, washing fastness, and handling. We believe that polymer-encapsulated pigments show promise for use in textile inks. [ABSTRACT FROM AUTHOR]

The organosilicon terpolymer scale inhibitor (EAVT) was synthesized by copolymerization of epoxy succinic acid, vinyl triethoxysilane and acrylic acid as starting materials and azobisisobutyronitrile as initiator. The influence of polymerization conditions on the performance of EAVT calcium scale inhibition was explored, and the performance of EAVT on single scale and composite scale was evaluated. The results show that the optimal synthesis conditions are that under the temperature of 65, 4 hours, 6 wt% of initiator, and the ratio of 0. 810. 8(epoxy succinic acid, acrylic acid, and vinyl triethoxysilane). When EAVT is 100 mg/ L, its scale inhibition rates for calcium magnesium scale and barium strontium scale in the formation water of a certain oilfield are 88. 28% and 87. 26%, respectively. [ABSTRACT FROM AUTHOR]

This article in the Russian Journal of Bioorganic Chemistry discusses the synthesis and antibacterial activity of 5-alkyloxymethyl derivatives of 2'-deoxyuridine. The compounds were synthesized through various chemical reactions and their structures were confirmed using spectroscopy and mass spectrometry. Some derivatives showed inhibitory effects on the growth of Micrococcus luteus. This research contributes to the development of new antibacterial drugs and provides insights into the mechanism of action of modified nucleosides. The article also acknowledges funding support and declares no conflicts of interest. [Extracted from the article]

Tetrafluoro(trifluoromethyl)-λ6-sulfanylethyl acrylate, a novel acrylate monomer, was polymerized by initiation with azobisisobutyronitrile (AIBN) at 60 °C to form a soft gel. This novel fluorinated ester was prepared by condensation of excess acryloyl chloride with 2-(tetrafluoro(trifluoromethyl)-λ6-sulfanyl)ethan-1-ol. Thermal decomposition of the polymer begins at 180 °C. Aqueous wetting by static contact measurement yielded a contact angle of 98°. [ABSTRACT FROM AUTHOR]

Post-assembly peptide modifications have become an integral part of medicinal chemistry nowadays. This exercise is useful in finding novel bioconjugates, therapeutic peptides and protein labelling. Therefore, in our attempts towards the modification of peptides, we have tried to insert thiophene moiety in dipropargyl dipeptide in the presence of AIBN and thioacetic acid. Surprisingly, instead of thiophene group introduction, we observe the serendipitous functionalization of amide group i.e. -NHCOCH3 is converted into -NHCHO group. [ABSTRACT FROM AUTHOR]

Foamed materials based on a biopolymer of crop straws are environmentally friendly, but ignitability limits their application. In this study, two nitrogenous layers were introduced onto corn straw by esterification and grafting for flame-retardant purposes. The inner thin nitrogenous layer consisted of imidazole rings, and the outer thick nitrogenous layer consisted of grafted acrylamide by a free-radical polymerization. The outer nitrogenous layer was simultaneously introduced into the system with a foaming process at 150 °C. Azodiisobutyronitrile acted both as initiator of the polymerization and the main foaming agent, and deionized water acted both as a plasticizing agent and an auxiliary foaming agent, which simplified the process and formula. It was found that cavities of two different sizes were formed. The nonuniformity of the foamed material was ascribed to the heterogeneous foaming precursor consisting of a rigid core and a soft shell. Its excellent flame-retard rating of UL-94 V-0 was ascribed to the two nitrogenous layers, which provides a sufficient nitrogen source for non-combustible gases. A relatively high compression strength of 17.7 MPa was partly due to the fiber of corn straw. [ABSTRACT FROM AUTHOR]

Renewable natural and synthetic basic substances can be used to produce biodegradable polymers. Several methods of the polymerization of terpene limonene have been evaluated. The polymerization methods evaluated are radical polymerization, cationic polymerization and thiol-ene polymerization. The free-radical polymerization of limonene with azobisisobutyronitrile (AIBN) as an initiator was carried out. The cationic polymerization of limonene was carried out using AlCl3 as a catalyst. The copolymerization of limonene with mercaptoethanol, 2-mercaptoethyl ether without an initiator and with an AIBN initiator was studied and it was also shown that polymerization can proceed spontaneously. The resulting compounds were investigated by NMR and FTIR spectroscopy. The values of the molecular weight characteristics of the samples obtained are presented, such as: number-average molecular weight, hydrodynamic radius and characteristic viscosity, depending on the method of production. The coefficients α (molecular shape) in the Mark–Kuhn–Houwink equation are determined according to the established values of the characteristic viscosity. According to the values obtained, the AC molecules in solution have parameters α 0.14 to 0.26, which corresponds to a good solvent and the molecular shape-dense coil. [ABSTRACT FROM AUTHOR]

Supplementary techniques to atom transfer radical polymerization (ATRP) have been studied to reduce the concentration of catalytic complexes used, aiming at a less costly and more environmentally friendly process for synthesizing polymeric materials. Initiators for continuous activator regeneration ATRP (ICAR ATRP) is one technique in which a source of primary free radicals allows the reactivation of catalytic species used in the conventional ATRP. Due to the technological relevance of the topic, this work aims to expand the contribution to literature with kinetic modeling and simulation study for an ICAR ATRP system not yet explored. For this purpose, it was investigated solution ICAR ATRP of methyl acrylate with copper-based catalysts and azobisisobutyronitrile as ICAR initiator. The method of moments was employed to derive material balance equations. We find that the kinetic mechanism that best represented the trends of experimental data from literature was the one that considered specific side reactions of acrylates, such as backbiting and radical catalytic termination. In the model fitting procedure, a nonlinear optimization process had to be developed to estimate the values of kinetic rate constants not yet reported in the literature. The values obtained for the missing kinetic rate constants are consistent with similar experimental systems found in the literature. The deterministic model obtained was then employed to study the concentration profile maps. Simulations allowed verifying the slow release of primary free radicals from ICAR initiator to reduce the deactivators in activators species continuously. In addition, it was possible to confirm that the ICAR ATRP can be thermoregulated. Parametric analyses showed that variations in kinetic rate constants and reaction stoichiometry can shape monomer conversion and the molecular properties of the polymer (e.g., molecular weight, dispersity, and end functionality).

Graft gelatin and poly(methyl methacrylate) copolymers were synthesized in the presence of the tributylborane—2,5-di-tert-butyl-p-benzoquinone (2,5-DTBQ) system. The molecular weight parameters and morphology of the polymer indicate that it has a cross-linked structure. Obtained data confirm the simultaneous formation of a copolymer in two ways: "grafting from" and "grafting to". It leads to the cross-linked structure of a copolymer. This structure was not obtained for copolymers synthesized in the presence of other initiating systems: azobisisobutyronitrile; tributylborane; azobisisobutyronitrile and tributylborane; azobisisobutyronitrile, tributylborane, and 2,5-di-tert-butyl-p-benzoquinone. In these cases, the possibility of the formation of the copolymer, simultaneously in two ways, was excluded. Graft gelatin and poly(methyl methacrylate) copolymers synthesized in the presence of the tributylborane—2,5-di-tert-butyl-p-benzoquinone system are promising in terms of their use in scaffold technologies due to the three-dimensional mesh structure, providing a high regenerative potential of materials. [ABSTRACT FROM AUTHOR]

Renewable natural and synthetic basic substances can be used to produce biodegradable polymers. Several methods of the polymerization of terpene limonene have been evaluated. The polymerization methods evaluated are radical polymerization, cationic polymerization and thiol-ene polymerization. The free-radical polymerization of limonene with azobisisobutyronitrile (AIBN) as an initiator was carried out. The cationic polymerization of limonene was carried out using AlCl3 as a catalyst. The copolymerization of limonene with mercaptoethanol, 2-mercaptoethyl ether without an initiator and with an AIBN initiator was studied and it was also shown that polymerization can proceed spontaneously. The resulting compounds were investigated by NMR and FTIR spectroscopy. The values of the molecular weight characteristics of the samples obtained are presented, such as: number-average molecular weight, hydrodynamic radius and characteristic viscosity, depending on the method of production. The coefficients α (molecular shape) in the Mark–Kuhn–Houwink equation are determined according to the established values of the characteristic viscosity. According to the values obtained, the AC molecules in solution have parameters α 0.14 to 0.26, which corresponds to a good solvent and the molecular shape-dense coil.

Bromination of 3-(methylfur-2-yl)- and 3-(methylfur-3-yl)-3-(diethoxyphosphoryl) acrylates with N-bromosuccinimide in carbon tetrachloride in the presence of azobisisobutyronitrile (AIBN) as a source of radicals is studied. It was found that if at least one α-position of the furan ring is free, the first bromine atom enters exactly there, and only after that bromination of the methyl group takes place. If both α-positions are free, the bromine atom first enters the position with the most high electron density, then the remaining α-position, and only after that bromination of methyl group takes place. The reaction rates differ significantly, therefore, it is possible to isolate in the pure state the compounds containing one, two, and three bromine atoms. [ABSTRACT FROM AUTHOR]

Herein, the unique method reports the efficacy of abundantly available urea for the generation of alkynyl radicals from 1‐bromoalkynes under metal‐free conditions. Urea as a sole reagent enabled the transformation of 1,1‐dirbomoalkenes or 1‐bromoalkynes to 1,3‐diynes via Homolytic Alkynyl Substitution (HAS). Urea further showed efficiency in synthesizing disubstituted alkyne via Sonogashira type cross‐coupling of 1,1‐dibromalkene/1‐bromoalkyne with aryl iodide. The Azobisisobutyronitrile (AIBN) trap detected the existence of short‐lived alkynyl radical during the reaction. This method might be the first report with Homolytic Alkynyl Substitution under metal‐free conditions, whereas Homolytic Aromatic Substitution is well reported. [ABSTRACT FROM AUTHOR]

The kinetics and mechanism of benzoyl peroxide- and azobisisobutyronitrile-initiated polymerization of acrylic acid and methyl acrylate in the temperature range of 20–40°C have been investigated. In the case of evacuation of the monomer + initiator system, the polymerization proceeds without heating or other energetic impacts on the system. The polymer yield depends on the initiator concentration and the temperature and time of sample thermostating. It has been shown by EPR that the monomers affect the rate of initiator decomposition into radicals. The structures of intermediate complexes formed in the acrylic acid + azobisisobutyronitrile system have been determined by quantum-chemical calculations, and the activation energies of the relevant processes have been calculated. [ABSTRACT FROM AUTHOR]

A quantum chemical simulation of the sixfold addition of 2-cyano-iso-propyl radical to fullerene C60 and the formation of a number of isomeric adducts is carried out. The thermodynamic characteristics of the elementary acts and the pattern of the spin density delocalization in fullerene C60 adducts containing an odd number of addends are determined. It is shown that the addition of up to four 2-cyano-iso-propyl radicals to fullerene C60 leads to the attachment of radicals to the tops of the radilene of the fullerenyl part of the adducts. The addition of the fifth 2-cyano-iso-propyl radical proceeds to the atoms more distant from the previously attached addends in the tetrakisadduct. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerator (TENG), a green energy harvester, can harvest mechanical energy from human motion to electric energy to be applied in wearable electronics and sensor network. Porous materials played an important role in enhancing electric performance of TENG. In this paper, Azobisisobutyronitrile (AIBN) is used as a self‐reactive agent to modify Polydimethylsiloxane (PDMS) to form a self‐assembled porous structure (PDMS‐N10 film) through the difference in temperature between PDMS pre‐curing and AIBN decomposition. The PDMS‐N10‐based TENG exhibits a 2.5‐fold and 2.7‐fold improvement in output voltage and current as compared with PDMS without modification respectively. In addition, 116 light‐emitting diodes could be lighted up and 22 µF capacitor is charged. The TENG is also used as a sensor or trigger device for sensing the movements of elbow, knee, wrist, or finger, which can be applied in wearable devices because of the flexibility and durability as well as low cost. [ABSTRACT FROM AUTHOR]

A new method was developed for the metal-free cross-linking of silicone rubbers. This process uses azobisisobutyronitrile (AIBN) to selectively react with Si–H and vinyl groups as a free-radical initiator for the thermal curing of polymethylhydrosiloxane (PMHS) and polymethylvinylsiloxane (PMVS). The AIBN-initiated curing reaction between the Si–H groups of PMHS generated Si–O–Si and Si–Si cross-links. In contrast, PMVS was cured via the formation of C–C bonds through "methyl–vinyl" and "vinyl–vinyl" mechanisms. Curing reactions were performed at 80–120 °C in air and confirmed by 13C and 29Si solid state NMR analyses and swelling trials. [ABSTRACT FROM AUTHOR]

Methylation is a well‐known structural modification in organic and medicinal chemistry. In addition to using conventional methylation reagents for direct methylation, indirect methylation approaches have been also successfully applied, particularly to tackle the isolation difficulty among the methylated product, the unreacted starting material, and the dimethylated by‐product due to the structural similarities between them. This review summarizes recent advances in the synthesis of methylated products through indirect approaches – transforming functionalized intermediates into the methylated products. The indirect methodologies surveyed in this review are useful for chemists to select appropriate methylation strategies, particularly for the challenging synthesis of methylated products at a large scale in drug discovery. Abbreviations: AIBN: azobisisobutyronitrile; Cbz: carbobenzyloxy; DBU: 1,8‐diazabicyclo[5.4.0]undec‐7‐ene; DIBAL: diisobutylaluminium hydride; FA: formic acid; Fmoc: fluorenylmethyloxycarbonyl; KOTMS: potassium trimethylsilanolate; LAH: lithium aluminium hydride; LiHBEt3: lithium triethylborohydride; PC: photocatalyst; PMHS: polymethylhydrosiloxane; PSMS: zinc bis(phenylsulfonylmethanesulfinate); SAM: S‐adenosylmethionine; SET: single electron transfer; TBAF: tetra‐n‐butylammonium fluoride; TBS: tert‐butyldimethylsilyl; TEA: trimethylamine; TFA: trifluoroacetic acid; TMS: trimethylsilyl; Ts: 4‐toluenesulfonyl. [ABSTRACT FROM AUTHOR]

Background/Aim: Microbial tetracycline (TC) pastes have been employed to treat oral bacterial infection. In the present study, we investigated the kinetic radicals-cavenging and pro-/anti-inflammatory activity of TC with or without visible light irradiation (VLI). Materials and Methods: The radical-scavenging activity of TC and minocycline (MC) was determined by differential scanning calorimetry (DSC). The stoichiometric factor (n) and the rate constant of inhibition and propagation (kinh/kp) were determined. The levels of cyclooxygenase-2 (Cox2), tumor necrosis factor-α (Tnfα) or nitric oxide synthase 2 (Nos2) mRNA in RAW264.7 cells stimulated with lipopolysaccharide (LPS) were investigated using real-time reverse transcriptasepolymerase chain reaction. Results: The n and kinh/kp values for 1 mM TC in 2,2'-azobisisobutyronitrile and benzoyl peroxide systems were 0.1-0.2 and 119-250, respectively, whereas the corresponding values for quercetin (QU) and resveratrol (RE) were 2-4 and 7-15, respectively. In RAW264.7 cells stimulated with LPS, Cox2 and Tnfα mRNA were over-expressed in the presence of TC. MC downregulated only the expression of Cox2 by about 50% in LPSstimulated cells. The anti-inflammatory activity determined on the basis of Cox2 inhibition declined in the order QU>RE>MC>TC. Upon application of VLI, only TC downregulated the expression of LPS-stimulated Cox2 and Tnfα mRNA. After exposure to VLI, TC, but not MC, markedly up-regulated hemoxygenase-1 (Ho-1) expression. Conclusion: TC is a chain-breaking antioxidant with a large kinh. Upon activation by VLI, TC may undergo degradation and its degradation products affect pleiotropic mediators such as Cox2, Tnfα and Ho-1. TC may be useful as a local photodynamic therapy for periodontal diseases. [ABSTRACT FROM AUTHOR]

Highlights • Fluorine modification is successfully conducted on titanium dioxide particles. • Fluoro-organic chains contribute to a very hydrophobic surface. • Improved anti-icing property is obtained through a very hydrophobic surface. Abstract In this study, fluorine modification was successfully conducted on titanium dioxide (TiO 2) to enhance the anti-icing property through fabricating a very hydrophobic surface. TiO 2 was firstly modified with 3-methacryloxypropyl-trimethoxysilane (MPS) to introduce C C bonds. Then, dodecafluoroheptyl methacrylate (DFHMA) monomers were successfully grafted on the TiO 2 particles via C C bonds introduced by MPS. Herein, azobisisobutyronitrile (AIBN) was used as initiator to initiate the reaction. The chemical components of the TiO 2 particles were investigated by X-ray photoelectron spectroscopy (XPS). XPS analysis of fluorine-modified TiO 2 revealed that the fluorine content reached a peak value of 7.3%, while the water contact angle enhanced to a maximum value of 146°. This water contact angle value of 146° was dramatically increased by 131° in comparison with unmodified TiO 2 , indicating a very hydrophobic surface. The crystallization temperature of a water droplet on the corresponding fluorine-modified TiO 2 decreased to −19.4 °C (10.3 °C decrease in comparison with that of a water droplet on unmodified TiO 2). Also, the freezing delay time on the fluorine-modified TiO 2 is more than 25 min under the testing temperature of −10 °C, exhibiting excellent anti-icing property. [ABSTRACT FROM AUTHOR]

In this work, we present a simplified versatile approach to synthesize monodisperse and robust entirely polymeric raspberry-like particles (RPs) via an in situ seeded polymerization method. The RPs with dual-scale hierarchical structure were prepared by absorption of monomer styrene, cross-linkable monomer ethylene glycol dimethacrylate (EDGMA) and azobisisobutyronitrile (AIBN) initiator into hollow P(styrene-divinylbenzene-trifluoroethyl methacrylate) [P(S-DVB-TFEMA)] nanoreactors, and then massive corona polymeric P(S-EDGMA) particles were in situ grafted onto the core hollow P(S-DVB-TFEMA) from the inside out, obtaining the robust all-polymer P(S-DVB-TFEMA)@P(S-EDGMA) RPs. The prepared RPs possess excellent mechanical and chemical stability toward long-term ultrasonic and acid/base treatment. Without post-modifications, the particulate film assembled by the RPs exhibited the static contact angle of 154° and high adhesion to water droplets. Theoretical model of the RPs and theoretical analysis, which corresponded well to experimental data, further reveal the high adhesive phenomenon. More importantly, the prepared sticky superhydrophobic surface colored by fluorescent dye can be utilized as “a mechanical hand” for micro-droplet transportation with high visibility in UV dark chamber. Thus, we anticipate that the sticky superhydrophobic surface constructed by the robust all-polymer RPs will offer great potential applications in micro-droplet manipulation and biological detection. [ABSTRACT FROM AUTHOR]

A compatible and practical (di)arylmethylation of phosphorylamides was successfully accessed in the presence of copper iodide as the catalyst, azodiisobutyronitrile as the radical initiator, and di‐tert‐butyl peroxide as the oxidant. Both methylarenes and diaryl methanes were compatible under the oxidative conditions, enjoying broad functional groups tolerance (51 examples) and good efficiency (up to 90 % yields). A CuI‐catalyzed phosphorylamidation of benzylic C–H bonds was demonstrated. Both methylarenes and diaryl methanes were compatible in the system with broad functional groups tolerance and good efficiency (51 examples, up to 92 % yields). [ABSTRACT FROM AUTHOR]

Polymerization of methyl methacrylate in bulk in the presence of 4-ethynylcoumarin and 4-butadiynylcoumarin (AIBN, 60 °C) leads to the formation of fluorescent polymers. A hypsochromic shift of fluorescence band maxima of polymer solutions is observed in dichloromethane. It was suggested using the quantum chemical calculations that 4-ethynylcoumarin is attached to the macroradical via the terminal carbon atom of the ethynyl group. The samples of fluorescent organic glasses were prepared. It was established that the addition of coumarins do not influence the microhardness of organic glass. [ABSTRACT FROM AUTHOR]

A cobalt-catalyzed strategy for N -arylmethylation of phosphorylamides was herein achieved with the assistance of azodiisobutyronitrile as the radical initiator and di- tert- butyl peroxide as the oxidant. Both methylarenes and diaryl methanes were compatible under the oxidative conditions, expressing broad substrate scope (51 examples) and high efficiency (up to 87% yield). [ABSTRACT FROM AUTHOR]

Tetra(meso-aryl)porphyrins containing 2,6-dimethoxyphenol unit distant from the macrocycle and adjacent to it have been prepared. Radical scavenging activity of the obtained compounds has been estimated in the model reaction of ethylbenzene oxidation initiated by azobisisobutyronitrile. It has been shown that the phenol hydroxy group ability to inhibit ethylbenzene oxidation depends on the environment of phenol group. [ABSTRACT FROM AUTHOR]

A magnetic molecularly imprinted polymer (MMIP) adsorbent for imidacloprid was prepared using non-covalent approach with functionalized nano Fe 3 O 4 particles (magnetic cores), imidacloprid (template), acrylic acid (functional monomer), ethylene glycol dimethacrylate (cross linker) and azobisisobutyronitrile (initiator) and used for selective separation of imidacloprid from honey and vegetable samples. The polymers were characterized using FT-IR spectroscopy, SEM and TEM images. For analysis of imidacloprid LC-MS/MS equipment was used. Adsorption kinetics was best explained by pseudo-second-order kinetic model. Adsorption data fitted well into linearized Freundlich equation (R 2  > 0.98). Scatchard plot analysis indicates the presence of two classes of binding sites in the MMIPs with the C max of 1889.6 µg g −1 and 65448.9 µg g −1 , respectively. MMIPs demonstrated much higher affinity for imidacloprid over structurally similar analogues acetamiprid (α = 23.59) and thiamethoxam (α = 17.15). About 87.1 ± 5.0% and 90.6 ± 5.6% of the added imidacloprid was recovered from MMIPs in case of fortified eggplant and honey samples, respectively. [ABSTRACT FROM AUTHOR]

Simulations of SADT values based on the heat balance of the system are presented for azobisisobutyronitrile (AIBN). These simulations used kinetic parameters obtained from heat flow calorimetry experiments performed at temperatures in the stability range of low-temperature (L-T) polymorph of AIBN. Thermal Activity Monitor (TAM) data were collected in the range of 55–70 °C. The simulated SADT value for L-T AIBN amounts to 46 °C. This is very similar to the computed results obtained in the BAM project (Malow et al., 2015; Roduit et al., 2015; Moukhina, 2015; Kossoy et al., 2015) for the high-temperature (H-T) form of AIBN which amounts to 47 °C and is also in full agreement with the large scale experimentally found SADT of AIBN (47 °C) (Malow et al., 2015). The prerequisites for collecting proper kinetic data for the quasi-AC type energetic materials in which the phase change phenomena (polymorphic transformation or melting) precedes the decomposition are discussed. The apparent paradox when the application of incorrect kinetics applied in narrow α  or T ranges may sometimes result in the correct predictions of such safety parameters, such as SADT, is also explained. [ABSTRACT FROM AUTHOR]

Complex coacervate adhesive analog of the glue secreted by a marine polychaete (Phragmatopoma California) was studied for gluing a wet bone. The aim of this in-vitro study is to investigate bond strength and solubilization of a complex, coacervate adhesive. A complex coacervate adhesive was synthesized by mixing aminated gelatin and polyphosphodopamid. Polyphosphodopamide (Poly (DMA- co -MOEP)) was synthesized by free radical polymerization of 2-(methacryloyloxy) ethyl phosphate (MOEP) and dopamine methacrylamide (DMA) (in the three ratios of MOEP to DMA: 11, 7, and 3) initiated with Azobisisobutyronitrile (AIBN) in MeOH at 60 °C for 24 h. The structure of polymers was characterized by IR and 1 H NMR spectra. The surface charges of aminated gelatin were positive, and its average zeta potential was about 31.08 mV: this shows gelatin was slightly aminated. For obtaining the optimum condition of adhesive, at first we changed the amount of the cross-linkable groups, dopamine (DOPA) sidechains in DMA, and then we investigated bond strength and solubilization behaviors. After obtaining the optimal amount of DOPA sidechains in the adhesive, we added 10% Wt human bone nanopowder (HBN) to the adhesive as filler and surveyed that behavior again. Results showed that with increase in DOPA sidechains in the adhesive, bond strength increased and solubilization rate decreased. Also, by adding bone nanopowder to the adhesive, bond strength and solubilization rate increased. The SEM images of this complex coacervate adhesive show a porous structure where in most of the porosities are in the range of 10–50 μm. Cytotoxicity effect of the adhesive and the nanocomposite adhesive were investigated on bone marrow mesenchymal primer cells: the results demonstrated cell growth and proliferation. This study shows that complex coacervate nanocomposite adhesive is a good candidate to act as a bone adhesive for sternal closure. [ABSTRACT FROM AUTHOR]

This paper presents a biomimetic rose petal whose contact angle hysteresis can be reversibly tuned by photo-illumination. With azobenzene interpenetrating polymer network, the micron- and nano-scale surface structure of a rose petal was duplicated. By changing the exposure light wavelength, the surface free energy of the artificial petal was modulated between trans -to-cis azobenzene photo-isomerations. The static contact angle of the artificial petal can be tuned to range from 99.2 ± 0.9° to 140.9 ± 1.8°. The contact angle hysteresis between 50.3 ± 0.6° and >84° can be achieved. Comparing to the value measured on a real rose petal, the fabricated counterpart presents more prominent petal effect in terms of larger static contact angle and greater contact angle hysteresis. [ABSTRACT FROM AUTHOR]

In an anticipation to produce biodegradable additives with multifunctional performance for a cost‐effective lubricant composition, copolymers are synthesized by incorporating rice bran oil, peanut oil, β‐pinene in the backbone of isodecyl acrylate through microwave irradiation method using AIBN (azobisisobutyronitrile) as radical initiator. The prepared polymers are characterized by spectral techniques (IR, NMR) and SEC‐GPC analysis, thermal stability was determined by thermogravimetric analysis. Performance of the polymers as antiwear (AW), pour point depressant (PPD), viscosity modifier/viscosity index improver (VII) in different mineral base oils (SN1 and SN2) were done by standard ASTM methods. Biodegradability test of the polymers was carried out by disk diffusion (DD) and soil burial test methods. The copolymers of rice bran oil showed better viscosity index values and AW property, whereas the copolymers of peanut oil found to be most effective as PPD. Copolymers with higher concentration of green units showed better performance as viscosity modifier, pour point depressant and AW performance along with excellent biodegradability. POLYM. ENG. SCI., 2017. © 2017 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

A new oxidative system of tert -butyl hydroperoxide (TBHP)/azodiisobutyronitrile (AIBN) has been used for the first time for a convenient, metal-free synthesis of substituted 2-aminothioazoles from active methylene ketone derivatives and thiourea. The reaction is postulated to proceed via an oxidative cyclization initiated by a radical process and followed by a condensation reaction. [ABSTRACT FROM AUTHOR]

ABSTRACT: Polystyrene has been typically prepared with radical polymerization by benzoyl peroxide (BPO) or azobisisobutyronitrile (AIBN). In this report, polymerization of styrene was carried out by radical cations of polyaniline (PANI). Polarons of conducting polymers are consisting of radical cations. The polarons bear electrical conduction as a charge carrier. We employ the polarons as an initiator for radical polymerization. Polymerization of styrene and acrylonitrile by the polarons was conducted to explore new possibility of conducting polymers. Fourier‐transfer infrared absorption (FTIR) spectroscopy measurements for the resultant polymers obtained with polarons of polyaniline indicates that the polystyrene thus synthesized grows from polyaniline. The qualitative solubility, average molecular weight, and thermal stability are comparable to that of polystyrene obtained by the common method with BPO. Radical polymerization by polarons may provide a new avenue for radical polymerizations through application of conducting polymer. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 805–811 [ABSTRACT FROM AUTHOR]

Polymer microparticles with size-controlled single pore was synthesized successfully using seeded emulsion polymerization. The pore size can be changed with relevant parameters. A scanning electron microscope(SEM) was used to characterize their pore size and morphology. Through measurement and calculation of SEM images, the change rules of pore size with the amount of monomer and porogen were taken. [ABSTRACT FROM AUTHOR]

Synthesis of Poly (N-vinyl pyrrolidone-maleic anhydride-methyl methacrylate) terpolymer using azobisisobutyronitrile in 1,4-dioxan is described. The polymers with different composition were synthesized and characterized using FTIR, 1HNMR, 13NMR, TGA and DSC techniques. The monomer-monomer interactions were studied using Finemann-Ross and Kelen-Tudos methods by calculating the reactivity ratio. The reactivity ratio r1 and r2 with respect to methyl methacrylate and N-vinylpyrrolidone-maleic anhydride complexomer are found to be 6.05 and 0.06 respectively. The study showed methyl methacrylate have higher reactivity than N-vinyl-2-pyrrolidone-maleic anhydride complex, i.e., the terpolymer contained methyl methacrylate in higher ratio. The thermal stability of poly (N-vinyl pyrrolidone-maleic anhydride-methyl methacrylate) was 165°C and the glass transition temperature was found to increase from 153°C to 182°C as MMA concentration increase. The studies indicate the activity of the polymer to inhibit bacterial growth is very poor. [ABSTRACT FROM AUTHOR]

Abstract: In the present study, a polar‐embedded reversed‐phase liquid chromatographic stationary phase that contained internal sulfone groups was prepared. The synthesis involved the “thiol‐ene” click chemistry between the vinyl functionalized silica and 1‐octadecanethiol, followed by the oxidization of sulfide to sulfone groups. The resulting material simultaneously possessed the alkyl chain, i.e. C18, and the internal sulfone groups. Elemental analysis demonstrates that the element contents of the C18/sulfone silica were C 8.94%, H 1.87% and S 0.66%. Chromatographic evaluations indicate that the C18/sulfone stationary phase exhibited a little less retention than the C18/sulfide one. A comparable chromatographic performance of neutral analytes was obtained on these two columns, but much better chromatographic performance in the case of basic and acid analytes was obtained on C18/sulfone stationary phase with additional features such as lower silanol activity, better stability (stable working conditions of pH 1.0–10.0), and better compatibility with 100% aqueous mobile phases. The batch‐to‐batch reproducibility was acceptable (the RSDs of retention times for the probes were no higher than 1.73%), demonstrating the suitability of the applied synthetic strategy for the new stationary phase. The C18/sulfone is a promising polar‐embedded RPLC stationary phase. [ABSTRACT FROM AUTHOR]

A stability indicating high performance liquid chromatography method has been developed for the determination of triamcinolone acetonide (TCA) and its main degradation products in ointment formulations. The method, based on extensive stress testing using metal salts, azobisisobutyronitrile, acid, base and peroxide, showed that TCA undergoes oxidative degradation. All degradation products were identified using HPLC mass spectrometry. Separation and quantification was achieved using an Altima C18 RP18 HP column (250 × 4.6 mm 2 , with 5 μm particles) using a mobile phase consisting of acetonitrile and water buffered at pH 7 using 10 mM phosphate buffer. A gradient mode was operated at a flow rate of 1.5 ml/min and detection was at 241 nm. The method showed linearity for TCA and Impurity C in 0.02–125% of the workload, both square roots of the correlation coefficients were larger than 0.9999. Repeatability and intermediate precision were performed by six consecutive injections of both 1.25% and 125% of the work load for both TCA and Impurity C divided equally over two days. RSD were 0.6% and 0.7% for TCA and 0.5% and 0.1% for Impurity C respectively. Accuracy was determined as well, the average recoveries were 99.5% (±0.1%, n = 3) for TCA and 96.9% (±1.3%, n = 3) for impurity C respectively from spiked ointment samples. The robustness was also evaluated by variations of column (old vs new), mobile phase pH and filter retention. The applicability of the method was evaluated by analysis of a commercial ointment formulation. Interestingly, the extensive stress tests were able to predict all degradation products of TCA in a long term stability ointment sample. [ABSTRACT FROM AUTHOR]

Molecularly imprinted thin layers were prepared in silica capillaries by using two different surface polymerization strategies, the first using 4,40-azobis(4-cyanovaleric acid) as a surface-coupled radical initiator, and the second, S-carboxypropyl-S'-benzyltrithiocarbonate as a reversible addition-fragmentation chain transfer (RAFT) agent in combination with 2,20-azobisisobutyronitrile as a free radical initiator. The ability to generate imprinted thin layers was tested on two different polymerization systems: (i) a 4-vinylpyridine/ethylene dimethacrylate (4VP-EDMA) in methanol-water solution with 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) as a template; and (ii) methacrylic acid/ethylene dimethacrylate (MAA-EDMA) in a chloroform solution with warfarin as the template molecule. The binding properties of the imprinted capillaries were studied and compared with those of the corresponding non-imprinted polymer coated capillaries by injecting the template molecule and by measuring its migration times relative to a neutral and non-retained marker. The role of running buffer hydrophobicity on recognition was investigated by studying the influence of varying buffer acetonitrile concentration. The 2,4,5-T-imprinted capillary showed molecular recognition based on a reversed phase mechanism, with a decrease of the template recognition in the presence of higher acetonitrile content; whereas warfarin-imprinted capillaries showed a bell-shaped trend upon varying the acetonitrile percentage, illustrating different mechanisms underlying imprinted polymer-ligand recognition. Importantly, the results demonstrated the validity of affinity capillary electrochromatography (CEC) to screen the binding properties of imprinted layers. [ABSTRACT FROM AUTHOR]

The solubility of 2,2'-azobisisobutyronitrile (AIBN) in pure methanol, ethanol, acetone, benzene, ethyl acetate, and a mixture of methanol and water was measured in the temperature range from 268.15 to 325.15 K at atmospheric pressure. The AIBN solubility was sensitive to the temperature in all pure solvents. The solubility in the binary mixture of methanol and water increased as the methanol fraction and temperature increased. The data were correlated with the modified Apelblat, Van't Hoff, and Buchowski-Ksiazczak λh equations. Other results showed that two AIBN polymorphs formed after the crystallization: form I, in a monoclinic cell, and form II, in a triclinic cell, which confirmed the two AIBN crystal structures reported in the literature. Additionally, the initial concentration and cooling rate of the AIBN crystallization had dominant roles in affecting the polymorphic forms of the AIBN crystals. The crystallization conditions were optimized in a 2 L crystallizer to yield crystals with the desired morphology and polymorphs, which resolved the caking issue experienced in the industrial production of AIBN. The optimized conditions were tested in a 20 L crystallizer. [ABSTRACT FROM AUTHOR]

The radical-initiated C-H bond functionalization of cyclic ethers with imines represents an efficient way to form C-C bonds and construct 1,2-amino ethers. Despite being a net redox-neutral process, most examples require excess amounts of radical reagents or oxidants to continuously generate the radical species. Herein, we report an atom-economic protocol for the radical addition of cyclic ethers to imines without the need for any oxidant, metal salt, delicate catalyst, or UV irradiation. In the presence of small amounts of AIBN (2 mol-%), tetrahydrofuran smoothly undergoes the reaction with a variety of imines to afford 1,2-amino ethers in moderate to good yields. Preliminary mechanistic studies suggest that this transformation likely proceeds through a radical chain process with the hydrogen atom abstraction as the rate-determining step. [ABSTRACT FROM AUTHOR]

Radical copolymerizations of N -isopropylacrylamide (NIPAm) with acrylic acid (AA) initiated by azobisisobutyronitrile in supercritical carbon dioxide (scCO 2 , 55 °C, 27.6 MPa) were compared with those performed in MeOH at 55 °C. The AA compositions of the copolymers in scCO 2 were lower than those of the copolymers in MeOH and they increased upon decreasing the pressure of scCO 2 from 27.6 to 13.8 MPa. The glass transition temperatures of these copolymers deviated positively from those of respective homopolymers prepared in both media, with the copolymer obtained at a 50/50 feed ratio exhibiting the highest value of T g . FTIR spectroscopy revealed enhanced H-bonding between the amide group of the NIPAm and the carboxyl group of the AA in the copolymers in scCO 2 , suggesting that the much higher values of T g of these copolymers, relative to those in MeOH, arose presumably from the more highly alternating sequences of their NIPAm and AA units. [ABSTRACT FROM AUTHOR]