Acrylate Moiety Research Articles

Stable Ketenyl Anions via Ligand Exchange at an Anionic Carbon as Powerful Synthons.

Under an atmosphere of carbon monoxide (CO), a (phosphino)diazomethyl anion salt [[P]-CN2 ][K(18-C-6)(THF)] (1) ([P]=[(CH2 )(NDipp)]2 P; 18-C-6=18-crown-6; Dipp=2,6-diisopropylphenyl) undergoes a facile N2 /CO exchange reaction giving the (phosphino)ketenyl anion salt [[P]-CCO][K(18-C-6)] (2). Oxidation of 2 with elemental Se affords the (selenophosphoryl)ketenyl anion salt [P](Se)-CCO][K(18-C-6)] (3). These ketenyl anions feature a strongly bent geometry at the P-bound carbon and this carbon atom is highly nucleophilic. The electronic structure of the ketenyl anion [[P]-CCO]- of 2 is examined by theoretical studies. Reactivity investigations demonstrate 2 as a versatile synthon for derivatives of ketene, enolate, acrylate and acrylimidate moieties.

Structural and adhesion properties of waterborne polyurethane adhesives containing nanosilica dispersion obtained with different physical mixing procedures

Nanosilica dispersion was added to waterborne polyurethane dispersion by using three different physical mixing procedures differing in the flow regime (tangential, laminar, radial) and the stirring rate (300–2400 rpm). The influence of the physical mixing procedure on the structural, thermal, rheological, mechanical, surface and adhesion properties of the polyurethanes (PUs) containing 1 wt% nanosilica was evaluated. The nanosilica in the dispersion was functionalized with acrylic moieties and showed high surface tension and negative Z potential values. The PU + nanosilica blend made with higher shear rate and laminar flow regime showed high homogeneous dispersion of the nanosilica particles and greater extent of intercalation between the soft segments of the polyurethane, this led to higher thermal stability. Unexpectedly, the better dispersion of the nanosilica in the PU matrix decreased the wettability of the PU + nanosilica materials due to the migration of acrylic moieties from the nanosilica particles to the surface. As a consequence, a decrease of the final T-peel strength was found. However, the single lap-shear strength did not change by adding nanosilica because of the scarce improvement of the mechanical properties in the PU + nanosilica materials.

An aqueous mediated ultrasensitive facile probe incorporated with acrylate moiety to monitor cysteine in food samples and live cells

A colorimetric probe TQA ((E)-4-(((8-(sec-butoxy)-2,3,6,7-tetrahydro-1H,5H-pyrido[3,2,1-ij]quinolin-9-yl)methylene)amino)benzylacrylate) possessing greater potent towards the sensing of cysteine was successfully synthesized and characterized. The aqueous soluble probe TQA detects Cys based on “ON-OFF” effect with excellent absorbance and emission properties. The probe TQA detects Cys up to its ultra-low level concentration of 1.5 nM and also quantifies the Cys up to 5.05 nM with the quicker response time of 140 s (2.3 min). In addition, the color change produced by the probe TQA on integrated with Cys was also identified easily via paper strip, cotton wool buds and RGB color picker app in smart mobiles. Further, the admirable selectivity and sensitivity of the probe TQA towards Cys extends its utility towards food samples and imaging of live HeLa cells.

Responses to single and multiple temperature-, medium-, and pH-stimuli triggering reversible shape shifts in hydrogel actuators

Adaptivity is an essential capability of creatures to develop skills for surviving and reproducing. Mimicking such behavior would enable the design of biologically inspired functions. Hydrogel actuators are promising candidate materials capable of stimuli-responsive movements via water uptake and release. Here, for the first time, the adaptive-like movement of reprogrammable hydrogel actuators is demonstrated by integrating two independent functions: a temperature-triggered actuation and a medium- and pH-based modulated swelling, into one multiphase network. Reversible crystallization of poly(ε-caprolactone) (PCL) provided bending movements up to 71° (realized by temperature changes between 5 °C and 40 °C). Changing solvent from water to ethanol increased swellability up to 240 vol%. Bending angles decreased by 32° as some PCL fractions are dissolved in ethanol and cannot participate in the crystallization-induced elongation guiding the movement. When the actuators were modified with acrylic acid moieties, a modulated swelling between 270 vol% at pH = 13 and 130 vol% at pH = 1 was achieved. The resulting swelling/deswelling response induced reversible bending movements up to 54°. In consequence, the coupled functionalities (actuation and modulated swelling) resulted in conditioned actuation behavior as an intermediate feature between stimuli-sensitivity and adaptivity.

Efficient Physical Mixing of Small Amounts of Nanosilica Dispersion and Waterborne Polyurethane by Using Mild Stirring Conditions

Good dispersion of nanosilica particles in waterborne polyurethane was obtained by mild mechanical stirring when 0.1-0.5 wt.% nanosilica in aqueous dispersion was added. The addition of small amounts of nanosilica produced more negative Z-potential values, increased the surface tension and decreased the Brookfield viscosity, as well as the extent of shear thinning of the waterborne polyurethane. Depending on the amount of nanosilica, the particle-size distributions of the waterborne polyurethanes changed differently and the addition of only 0.1 wt.% nanosilica noticeably increased the percentage of the particles of 298 nm in diameter. The DSC curves showed two melting peaks at 46 °C and 52 °C, as well as an increase in the melting enthalpy. In addition, when nanosilica was added, the crystallization peak of the waterborne polyurethane was displaced to a higher temperature and showed higher enthalpy. Furthermore, the addition of 0.1-0.5 wt.% nanosilica displaced the temperature of decomposition of the soft domains to higher temperatures due to the intercalation of the particles among the soft segments; this led to a change in the degree of phase separation of the waterborne polyurethanes. As a consequence, improved thermal stability and viscoelastic and mechanical properties of the waterborne polyurethanes were obtained. However, the addition of small amounts of nanosilica was detrimental for the wettability and adhesion of the waterborne polyurethanes due to the existence of acrylic moieties on the nanosilica particles, which seemed to migrate to the interface once the polyurethane was cross-linked. In fact, the final T-peel strength values of the joints made with the waterborne polyurethanes containing nanosilica were significantly lower than the one obtained with the waterborne polyurethane without nanosilica; the higher the nanosilica content, the lower the final adhesion. The better the nanosilica dispersion in the waterborne polyurethane+nanosilica, the higher the final T-peel strength value.

Comparative hydrodynamic characterisation of two hydroxylated polymers based on α-pinene- or oleic acid-derived monomers for potential use as archaeological consolidants

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.

Oxidative Degradation of Thermosets Based on Thioketal Cleavable Linkages in Aqueous Environment

Thermosets are rigid, infusible, and unmolded materials containing three-dimensional (3D) cross-linked structures. They are considered a fundamental pillar in the international economy, which are produced by 65 million tons annually. The responsive cross-linking moieties provide the thermosets characterized with outstanding physicochemical properties such as stiffness, degradability, and chemical and thermal resistance. We prepared degradable thermoset materials using thioketal (TK) cross-linkers, which underwent main-chain or side change degradation in the presence of hydrogen peroxide in water. TK cross-linkers at different concentrations (5, 10, and 20% wt %) were polymerized with 2-hydroxyethyl acrylate (HEA) or with 2-hydroxyethyl methacrylate (HEMA) and 1-vinyl-2-pyrrolidone (PD) to produce cross-linked poly(HEA) and poly(HEMA-PD) by free radical polymerization, respectively. The resultant polymer materials completely degraded in hydrogen peroxide/water (3–30%, vol). Using isophorone diisocyanate, we also produced degradable polyurethane based on TK-bearing diol. We prepared a 3D degradable thermoset using the Direct-Ink-Writing (DIW) 3D printing technology, which was charged by diethylene glycol diacrylate (15%, wt %) and a prepolymer (isophorone diisocyanate terminated by acrylate moieties) containing diol-thioketal linkage (15%, wt %). Finally, we found that TK-poly(HEA) underwent microbial degradation by Lactobacillus jensenii at 37 °C, which indicates a benign eco-friendly effect.

Optimizing reduced capture antibody conjugation to encoded hydrogel microparticles for enhanced multiplex immunoassays

Multiplex detection of protein biomarkers in biological fluids facilitates high-throughput detection using small-volume samples, thereby enhancing efficacy of diagnostic assays and proteomic studies. Graphically encoded hydrogel microparticles conjugated with capture antibodies have shown great potential in multiplex immunoassays by providing superior sensitivity and specificity, a broad dynamic range, and large encoding capacity. Recently, the process of post-synthesis conjugation of reduced capture antibodies to unreacted acrylate moieties in hydrogel particles has been developed to efficiently prevent the aggregation of capture antibodies inside particles, which occurs when using conventional conjugation methods. This direct conjugation process yielded robust assay performance through homogeneous conjugation of the capture antibodies, and avoided the use of hydrolytically unstable linker additives. However, no research has been conducted to optimize the process of conjugating capture antibodies to the particles. We here present a strategy to optimize capture antibody conjugation based on the finding that excessive addition of capture antibodies during incubation can rather lower the amount of capture antibodies conjugated to the particles for some types of capture antibodies. Based on our optimized capture antibody conjugation process, a singleplex immunoassay for a selected target was conducted. Enhanced sensitivity compared with previous studies was confirmed. We also validated the increased specificity of multiplex detection through our optimization process. We believe that the optimization process presented herein for capture antibody conjugation will advance the field of encoded hydrogel microparticle-based immunoassays.

A simple “turn-on” fluorescent probe capable of recognition cysteine with rapid response and high sensing in living cells and zebrafish

Cysteine (Cys), an essential biological amino acid, participates several crucial functions in various physiological and pathological processes. The sensitive and specific detection of Cys is of great significance for understanding its biological function to disease diagnosis. Herein, we designed and synthesized a simple fluorescence sensor 2-(benzothiophen-2-yl)-4-oxo-4H-chromen-3-yl acrylate (BTCA) composed of a flavonol skeleton as the fluorophore and acrylic ester group as the recognition receptor. Probe BTCA displayed high selectivity and extremely fast response toward Cys in phosphate buffer solution in the presence of other competitive species even Homocysteine (Hcy) and Glutathione (GSH) owing to a specific conjugate addition-cyclization reaction between the acrylate moiety and Cys. The photoluminescence mechanism of probe BTCA toward Cys was modulated by excited state intramolecular proton transfer (ESIPT) process. The sensing property for Cys was studied by UV–Visible, fluorescence spectrophotometric analyses and time-dependent density functional theory (TD-DFT) calculations, those results indicated that probe BTCA possessed excellent sensitivity, higher specificity, dramatically “naked-eye” fluorescence enhancement (30-fold), high anti-interference ability, especially immediate response speed (within 40 s). Additionally, the practicability of sensor BTCA in exogenous and endogenous Cys imaging in living cells and zebrafish was elucidated as well, suggesting that it has remarkedly diagnostic significance in physiological and pathological process.

Synthesis and evaluation of novel xanthine-acrylamides and xanthine-acrylates as insecticidal agents.

The design and discovery of novel pesticidal agents according to bioactive natural products is an important aspect of agrochemical innovation. New xanthine derivatives derived from natural xanthine or methylxanthines are rich resources that possess great potential to afford new active pesticidal molecules. Herein novel xanthine derivatives were designed through a strategy of combining the methylxanthine caffeine skeleton with the acrylamide or acrylate motif of cinnamic acid derivatives. A series of novel (E)-3-(1,3,7-trimethyl-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-8-yl)acrylic acid derivatives, caffeine-(E)-acrylamides and caffeine-(E)-acrylates, were synthesized and confirmed via melting points, 1 H NMR, 13 C NMR and high-resolution mass spectrometry. A single crystal of compound I12 was obtained to illustrate the trans-configuration of the vinyl double bond. Preliminary insecticidal evaluations showed that some of the compounds had favorable insecticidal potentials against Mythimna separata Walker at 200 mg L-1 . Some of the compounds exhibited excellent insecticidal activity against Plutella xylostella L. at low test concentrations, e.g. I18 and I24 with LC50 values of 0.0435 and 0.0133 mg L-1 , respectively, were found to be more potent than the insecticide control triflumuron. The structure-activity relationship (SAR) analysis is also given in detail. Compounds I12, I18, I24 and I26 generated from the integration of natural methylxanthine (caffeine) and acrylate moieties could be novel insecticidal leading compounds for further structural optimization. The SAR analysis may bring a new inspiration to the extensive and deep investigations on new xanthine derivatives in the agrochemical area.

Zwitterionic copolymer containing diallyldimethylammonium chloride and acrylic acid on carboxylated-MWCNTs

Plenty of procedures have been used to improve the hydrophilicity of membranes. The incorporation of carbon nanotubes has received a great deal of attention for this purpose. In this study, a zwitterionic copolymer, consists of diallyl dimethylammonium chloride, and acrylic acid moieties, was grafted to carboxylated-MWCNT via in-situ polymerization of monomers. The grafted copolymer simultaneously possesses positive and negative charges. The modification is done in a simple way, one step, and increases the hydrophilicity of the carboxylated-MWCNT significantly. FT-IR, FESEM, EDAX, and TGA were used to confirm the modification reactions. Nanocomposite membranes were fabricated by insertion of functionalized MWCNT into the PES casting solution. The effect of additives on membrane properties was investigated by the contact angle, porosity, zeta potential, swelling, morphology, and fouling studies. FESEM analysis showed that the cross-sectional morphology of membranes changed from finger-like to spongy. The hydrophilicity of the membrane surface demonstrated an incremental change afterward adding functionalized MWCNT. As a result of the increased hydrophilicity, the membrane fouling property improved significantly. The performance of the membranes in removing salts, heavy metals, and dyes was studied, and it was found that the membrane which has 5 wt% of the functionalized MWCNT had the best performance and at higher percentages, the efficiency decreased due to the accumulation between the additives. Moreover, the membranes are responsive to pH changes due to the presence of pH-sensitive additives, and studies have shown that the removal efficiency is improved under alkaline conditions.

Transposition of an acrylate moiety in TMSOTf-mediated reaction of alkynyl vinylogous carbonates gives heterocyclic dienes.

TMSOTf-mediated reaction of alkynyl vinylogous carbonates serendipitously gave 1,4-oxazepine and dihydropyran dienes via transposition of an ethyl acrylate moiety involving intramolecular cascade Prins-type cyclization/retro-oxa-Michael reaction/cycloisomerisation. The developed atom-economical protocol selectively provides an E double bond geometry. Dihydropyran dienes could be reduced diastereoselectively using Et3SiH/TMSOTf or could be transformed into polycyclic heterocycles by Heck reaction.

Dynamic hyaluronic acid hydrogel with covalent linked gelatin as an anti-oxidative bioink for cartilage tissue engineering

In the past decade, cartilage tissue engineering has arisen as a promising therapeutic option for degenerative joint diseases, such as osteoarthritis, in the hope of restoring the structure and physiological functions. Hydrogels are promising biomaterials for developing engineered scaffolds for cartilage regeneration. However, hydrogel-delivered mesenchymal stem cells or chondrocytes could be exposed to elevated levels of reactive oxygen species (ROS) in the inflammatory microenvironment after being implanted into injured joints, which may affect their phenotype and normal functions and thereby hinder the regeneration efficacy. To attenuate ROS induced side effects, a multifunctional hydrogel with an innate anti-oxidative ability was produced in this study. The hydrogel was rapidly formed through a dynamic covalent bond between phenylboronic acid grafted hyaluronic acid (HA-PBA) and poly(vinyl alcohol) and was further stabilized through a secondary crosslinking between the acrylate moiety on HA-PBA and the free thiol group from thiolated gelatin. The hydrogel is cyto-compatible and injectable and can be used as a bioink for 3D bioprinting. The viscoelastic properties of the hydrogels could be modulated through the hydrogel precursor concentration. The presence of dynamic covalent linkages contributed to its shear-thinning property and thus good printability of the hydrogel, resulting in the fabrication of a porous grid construct and a meniscus like scaffold at high structural fidelity. The bioprinted hydrogel promoted cell adhesion and chondrogenic differentiation of encapsulated rabbit adipose derived mesenchymal stem cells. Meanwhile, the hydrogel supported robust deposition of extracellular matrix components, including glycosaminoglycans and type II collagen, by embedded mouse chondrocytes in vitro. Most importantly, the hydrogel could protect encapsulated chondrocytes from ROS induced downregulation of cartilage-specific anabolic genes (ACAN and COL2) and upregulation of a catabolic gene (MMP13) after incubation with H2O2. Furthermore, intra-articular injection of the hydrogel in mice revealed adequate stability and good biocompatibility in vivo. These results demonstrate that this hydrogel can be used as a novel bioink for the generation of 3D bioprinted constructs with anti-ROS ability to potentially enhance cartilage tissue regeneration in a chronic inflammatory and elevated ROS microenvironment.

Investigation of the chemical changes during the thermal treatment of acrylonitrile‐co‐methyl acrylate‐polymer (polyacrylonitrile‐precursor) focusing on the fate of the methyl acrylate moiety

AbstractSeventeen samples of acrylonitrile (AN)‐co‐methyl acrylate (MA)‐polymer (MA content 0–11 mol%) are examined. Several selective isotopic labelings are employed (d1‐MA, d2‐MA, 13CO‐MA, CD3‐MA, d1‐AN, d2‐AN, and 15N‐AN). The thermal treatment under inert atmosphere is investigated to gain insight into the chemical transformation mechanisms concerning the MA sub‐unit. The volatiles are determined by means of evolved gas analysis (EGA) (Fourier transform infrared [FTIR] and GC/MS). Methanol is found for the first time as one decisive volatile stemming from the MA sub‐unit, next to water and carbon dioxide. In addition, methylamines are proven to be formed by reaction of ammonia with the MA sub‐unit, while a similar reaction of hydrogen cyanide (HCN) yielding in acetonitrile could be ruled out. Several volatile compounds could even be quantified. The non‐volatile polymeric material is characterized by means of simultaneous thermal analysis (differential scanning calorimetry, thermogravimetric analysis), in‐situ‐FTIR spectroscopy and sophisticated solid‐state NMR methods. Selected defined model compounds are synthesized and analyzed for comparison. Detailed reaction mechanisms for the thermal transformation are concluded from the results, pointing in particular to the importance of ammonia for all processes as stoichiometric and/or catalytic reagent.

A red dicyanoisophorone-based fluorescent probe for monitoring cysteine fluctuations due to redox imbalances in living organisms even in the presence of other biological molecules

A dicyanoisophorone-based fluorescent probe, DCI-Cys, with an acrylate moiety as the recognition group and a large Stokes shift (185 nm) was constructed to selectively detect cysteine (Cys). The probe showed long red wavelength emission (626 nm), exceptional sensitivity, and a rapid response. DCI-Cys specifically recognized Cys and allowed fluorescence bioimaging in HepG2 cells and zebrafish. DCI-Cys was successfully applied to monitor intracellular Cys fluctuations caused by redox changes induced by Hg2+ and resveratrol in cells. The probe may be useful for in-depth research on the action mechanisms of Hg2+ and resveratrol in the living systems and on the roles of Cys in pathophysiology.

A coumarin-based fluorescent probe for specific detection of cysteine in the lysosome of living cells

Cysteine (Cys), the only amino acid in the 20 natural amino acids that contains a reduced sulfhydryl group, plays important roles in the balance of redox homeostasis in biological systems. Lysosome is an important organelle containing a variety of hydrolases and has been proved to be the decomposition center of a variety of exogenous and endogenous macromolecular substances. In this research, a coumarin-based fluorescent probe MCA for the detection of Cys in lysosomes of living cells was developed. Due to the acrylate moiety, this probe exhibited high sensitivity (detection limit = 6.8 nM) and selectivity towards Cys superior to other analytes. Moreover, the probe was proved to be lysosome-targetable and showed good cell imaging ability and low cell toxicity.

A new simple ESIPT-based fluorescent probe for rapid detection of cysteine with high sensitivity and specificity and bioimaging in living cells

Based on Excited-State Intramolecular Proton Transfer (ESIPT) fluorophore and an acrylate moiety as Michael addition and leaving site, a simple but colorimetric turn-on fluorescent probe FVCA was designed and synthesized. Upon addition of Cys to the solution of FVCA, the absorption spectra changed from 375 nm to 460 nm (Δ85 nm) and afforded visible color change from colorless to yellow. Meanwhile, the fluorescence emission spectra emerged at 554 nm with remarkable changes, accompanying with an obvious fluorescence color change from colorless to bright green. In addition, FVCA exhibited rapid response (∼ 60 s), high sensitivity (detection limit: 8.37 nM), large strokes shift (∼ 94 nm) and excellent selectively to Cys over other biological mercaptans. Moreover, FVCA had strong anti-interference ability for Cys without any interference from other biologically-relevant thiols even Hcy and GSH, even obvious visible and fluorescence color changes. More, the sensing mechanism was proved to be the ESIPT-based addition-cyclization reaction process by 1H NMR, HRMS and TD-DFT. Importantly, FVCA can be used to image exogenous and endogenous Cys in living A549 cells with low toxicity.

Mechanically tunable photo-cross-linkable bioinks for osteogenic differentiation of MSCs in 3D bioprinted constructs

3D bioprinting technique renders a plausible solution to tissue engineering applications, mainly bone tissue regeneration, which could provide the microenvironment with desired physical, chemical, and mechanical properties. However, the mechanical and structural stability of current natural polymers is a critical issue in the fabrication of bone tissue-engineered scaffolds. To overcome these issues, we have developed 3D bioprintable semi-synthetic polymers derived from natural (sodium alginate, A) and synthetic (polyethylene glycol, PEG) biopolymers. In order to enhance the cross-linking properties and biocompatibility, we have functionalized these polymers with acrylate and methacrylate chemical moieties. These selected combination of natural and synthetic polymers improved the mechanical strength due to the synergistic effect of covalent as well as ionic bond formation in the hydrogel system, which is evident from the tested tensile data. Further, the feasibility of 3D bioprinting of acrylate and methacrylate functionalized PEG and hydrogels have been tested for the biocompatibility of the fabricated structures with human umbilical cord mesenchymal stem cells (UMSCs). Further, these bioprinted scaffolds were investigated for osteogenic differentiation of UMSCs in two types of culture conditions: namely, i) with osteoinduction media (with OIM), ii) without osteoinduction media (w/o OIM). We have examined the osteoinductivity of scaffolds with the activity of alkaline phosphatase (ALP) content, and significant changes in the ALP activity was observed with the stiffness of developed materials. The extent osteogenic differentiation was observed by alizarin red staining and reverse transcription PCR analysis. Elevated levels of ALP, RUNX2 and COL1 gene expression has been observed in without OIM samples on week 1 and week 3. Further, our study showed that the synthesized alginate methacrylate (AMA) without osteoinduction supplement with young's modulus of 0.34 MPa has a significant difference in ALP quantity and gene expression over the other reported literature. Thus, this work plays a pivotal role in the development of 3D bioprintable and photo-cross-linkable hydrogels in osteogenic differentiation of mesenchymal stem cells.

One-step UV-curable ligand copolymer coatings as non-migratory antioxidant packaging

Polymeric surface photografting is a desirable method to modify the interfacial interactions of inert materials and enable one-step surface functionalization e.g. antimicrobial, antifouling, bioprinting, and so on. Herein, a novel UV-curable lysine derivate ligand copolymer coating was synthesized using surfactant-free emulsion polymerization for use as a non-migratory antioxidant packaging coating. NMR was used to estimate the ratio of butyl acrylate (47 mol%) and benzophenone moiety (19 mol%) in the copolymer that would be optimal for UV-curable coating on the polypropylene (PP) film surface. The copolymer, containing 34 mol% of functional monomer, was photochemically grafted onto the PP film surface (365 nm, 90 s), and a large amount of COOH functional groups was detected on the PP film surface (302 ± 19 nM). The chemical and microstructural evaluations of the film confirmed the ligand compositions and grafting morphology of the ligand film (rough surface). The ligand film adequately chelated Fe+3 (215 ± 26 nM,) in an aqueous solution with pH of 5; this chelation imparted antioxidant properties to the ligand film. Furthermore, the ligand film was stored with virgin olive oil and vitamin C (pH = 7) inoculated with Fe+3, which significantly (p < 0.05) retarded the lag time of oxidation and degradation of the product, respectively. The EU migration test proved that this system did not leave any migrant residue, enabling the clean labeling of the system. This work bridged the research gap in non-migratory antioxidant packaging by developing a curable biomimetic ligand copolymer using a practical industrial scalable method that can be applied for packaging, cosmetics, and biomedical purposes.

Ester-Containing Imidazolium-Type Ionic Liquid Crystals Derived from Bio-based Fatty Alcohols

The need to take into account the life cycle of ionic liquids (ILs), from the sourcing of the raw materials involved in their synthesis to their disposal and degradation, has become paramount in the design of new IL-type molecular structures. In the case of 1-alkyl-3-methylimidazolium salts, one of the prominent IL families, there is an increasing demand for synthetic methods involving (i) substitution of the petro-based alkyl derivatives by readily available bio-sourced surrogates and (ii) functionalization of the alkyl tail with heterofunctional groups enabling the (bio)degradation of ILs after use. Herein, a straightforward and industrially viable synthesis of lipidic imidazolium salts is reported, starting from different bio-sourced fatty alcohols, including oleic, stearyl, and lauryl alcohols. This procedure is based on the acrylation of fatty alcohols, followed by the aza-Michael addition of the imidazole group onto the acrylate moiety. Subsequent quaternization, using either methyl iodide or methyl tosylate, provides a library of 1-alkylpropionate-3-methylimidazolium salts with various alkyl chain lengths (C18, C12, and C11) and incorporating different types of counteranions (iodide, tosylate, and tetrafluoroborate). These ester-containing analogues of classical 1-alkyl-3-methylimidazolium salts are all ILs, that is, with a melting point below 100 °C. In addition, most of them exhibit a liquid-crystal behavior and can be referred to as IL crystals (ILCs). The thermal stability, as well as the phase transitions of these ILs, has been investigated by thermogravimetric analysis, as well as differential scanning calorimetry, respectively, while the molecular structure into the crystalline phase and the mesophase is studied by X-ray scattering. Interestingly, ILCs featuring unsaturated alkyl tails exhibit a low melting point, close to room temperature, and the presence of the ester function is shown to provide an enhanced stabilization of the mesophase.