light curvable food-grade chemicals such as Itaconic Acid

A polymerizable difunctional photoinitiator 2-methylene-succinic acid bis-{2-[4-(2-hydroxy-2-methylpropionyl)phenoxy]ethyl} ester (IAHHMP) based on the commercial photoinitiator 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methylpropanone (HHMP) and a biorenewable itaconic acid is synthesized by esterification. The structure is confirmed by ultraviolet spectroscopy, Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy (1H NMR, 13C NMR) and thermogravimetric analysis. The photopolymerization behaviour of the photoinitiator is investigated using photo-differential scanning calorimetry and compared with that of two commercial photoinitiators, HHMP (or photoinitiator 2959) and 1-hydroxycyclohexyl phenyl ketone (or photoinitiator 184). The results show that IAHHMP has a strong UV absorption capacity at 245~300 nm and can initiate polymerization of monomers containing a double bond. The relative migration of IAHHMP is less than that of the systems containing an HHMP or 1-hydroxycyclohexyl phenyl ketone photoinitiator. Therefore, IAHHMP is expected to have potential applications in more environmentally friendly materials, such as in food and medical packaging.

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In pursuit of enhancing the mechanical properties, especially the tensile strength, of 4D-printable consumables derived from waste cooking oil (WCO), we initiated the production of acrylate-modified WCO, which encompasses epoxy waste oil methacrylate (EWOMA) and epoxy waste oil acrylate (EWOA). Subsequently, a series of WCO-based 4D-printable photocurable resins were obtained by introducing a suitable diacrylate molecule as the second monomer, coupled with a composite photoinitiator system comprising Irgacure 819 and p-dimethylaminobenzaldehyde (DMAB). These materials were amenable to molding using an LCD light-curing 3D printer. Our findings underscored the pivotal role of triethylene glycol dimethacrylate (TEGDMA) among the array of diacrylate molecules in enhancing the mechanical properties of WCO-based 4D-printable resins. Notably, the 4D-printable material, composed of EWOA and TEGDMA in an equal mass ratio, exhibited nice mechanical strength comparable to that of mainstream petroleum-based 4D-printable materials, boasting a tensile strength of 9.17 MPa and an elongation at break of 15.39%. These figures significantly outperformed the mechanical characteristics of pure EWOA or TEGDMA resins. Furthermore, the EWOA-TEGDMA resin demonstrated impressive thermally induced shape memory performance, enabling deformation and recovery at room temperature and retaining its shape at −60 °C. This resin also demonstrated favorable biodegradability, with an 8.34% weight loss after 45 days of soil degradation. As a result, this 4D-printable photocurable resin derived from WCO holds immense potential for the creation of a wide spectrum of high-performance intelligent devices, brackets, mold, folding structures, and personalized products.

The present work reports for the first time thiol-yne photoresins prepared from novel alkyne derivatives of isosorbide and its epimers, isomannide and isoidide. Isosorbide was selected as a key biobased monomer for this study in consideration of its unique rigid V-shaped structure and peculiar reactivity, as well as for the growing interest in this cyclic sugar due to its numerous industrial applications in polymer science. Dialkyl carbonate chemistry was used for the preparation of dipropargyl derivatives of isosorbide and its epimers via alkoxycarbonylation reaction conducted under mild conditions using catalytic amounts of 1,5,7-triazabicyclo[4.4.0]-dec-5-ene (TBD). Dialkyne monomers were then employed to produce biobased thiol-yne photoresins, formulated using trimethylolpropane tris-(3-mercaptopropionate) as a trifunctional thiol. The photopolymerization behavior was investigated by real-time Fourier-transform infrared spectroscopy and differential scanning calorimetry (DSC) to assess conversion efficiency and reaction kinetics. The resulting networks were characterized by DSC and dynamic mechanical thermal analysis. Furthermore, residual thiol groups enabled surface modification with poly-(ethylene glycol) methacrylate (PEGMA) to enhance hydrophilicity, as confirmed by contact angle measurements. Finally, the optimized isosorbide-based network formulation was successfully printed by digital light processing, achieving accurate 3D-printed structures.

Due to long-term problems related to environmental protection, economic aspects, and waste management in the chemical industry, it is justified to develop renewable polymers as an alternative to synthetic polymers. Two kinds of acrylic bio-renewable components were used for the modification of acrylated epoxidized soybean oil (AESO). The bio-based compositions used as photocurable binders to obtain the photocurable coatings with satisfactory properties and high bio content were then prepared. The kinetic of curing reaction of the oligomers and monomers towards radical photopolymerization and the properties of the cured coatings were fully investigated; the results are discussed in relation with the compounds’ structures. Important information about how to design and obtain renewable photocurable coatings with satisfactory properties was provided in this study. In this study, AESO resin was modified with renewable oligomer or (math)acrylate monomer to increase the reactivity and reduce the viscosity of the photoreactive system in order to obtain renewable and viable alternatives to petroleum-based polymeric materials with perfect film-forming properties. It turned out that both photopolymerization rate and hardness of cured coatings were increased significantly with the addition of modifiers; the use of a thiol modifier and change of the photoinitiator concentration allowed to improve the adhesion, hardness, and control of the photo-curing process.

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The ability to precisely measure photopolymerization kinetics is paramount to controlling curing characteristics and material properties in photocurable systems. Traditional methods used to measure kinetics, such as real-time Fourier-transform infrared spectroscopy (RT-IR), are often limited by broadening mechanisms intrinsic to the system and poor spectral resolution. In this work, we present an in situ NMR spectroscopy technique to monitor bulk photopolymerization reactions wherein the polymer system is separated from the locking solvent via a capillary insert and photoexcited using an LED-coupled fiber optic. This technique allows for the isolated observation of the bulk reaction system while also benefiting from the high spectral resolution and rich chemical information offered by NMR. Relative rate constants (k p ′) and ultimate monomer conversion were determined for four systems: neat hexyl acrylate, isobornyl methacrylate, N,N-dimethylacrylamide, and hexyl acrylate with cross-linker. By observing kinetic data of simple photopolymer systems, this work demonstrates the utility of in situ NMR photopolymerization as a complementary technique to conventional RT-IR and other methods for the kinetic monitoring of bulk photopolymer materials.

ABSTRACT The end-of-life treatment of thermoset polyurethane foam (PUF) is an environmental challenge that has remained unresolved for decades. Current chemical recycling strategies are economically prohibitive to implement due to the complex multi-step process and use of catalyst/solvent. Here, we report a one-step upcycling strategy that transforms PUF waste into 3D photo-printing resins without using any catalyst or solvent. Our process employs bio-based itaconic acid as a single reagent that not only degrades PUF into fragments but also generates photocurable vinyl end-groups in situ. Incorporation of additional bio-based monomers (tetrahydrofurfuryl methacrylate and l-lysine diisocyanate) allows formulation of a photo-sensitive resin. The corresponding 3D photo-printed polymer, made entirely from PUF waste and bio-monomers (excluding the photo-initiator), exhibits exceptional mechanical performance (tensile strength: 26.3 MPa, toughness: 16.2 MJ m−3) relative to other commercial 3D photo-printed polymers. Our simple process that upcycles polymer wastes using solely bio-derived reagents points to a promising direction towards sustainable development of polymer materials.

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Cationic photopolymerization offers a significant advantage over radical polymerization due to its resistance to oxygen inhibition and superior dimensional stability during the crosslinking process. In this study, we aim to advance the development of bio‐based monomers for cationic photopolymerization by synthesizing oxetane‐functionalized derivatives of adipic, itaconic, and citric acids. These three renewable acids were chosen for their multifunctionality and availability. The synthesized monomers, bis((3‐methyloxetan‐3‐yl)methyl) adipate (BOA), bis((3‐methyloxetane‐3‐yl)methyl) itaconate (BOI), and tris((3‐methyloxetane‐3‐yl)methyl) citrate (TOC), were fully characterized using nuclear magnetic resonance (NMR). Fourier transform infrared (FTIR) spectroscopy and photo differential scanning calorimetry (photo‐DSC) were employed to monitor the oxetane ring‐opening reaction kinetics and to determine the degree of conversion, revealing high reactivity in all monomers, reaching nearly complete conversion within 90 s. The mechanical properties of the UV‐cured films were assessed by dynamic mechanical thermal analysis (DMTA) and gel content measurements. Results indicated that the BOI‐based films exhibited higher glass transition temperatures (Tg) and crosslinking densities compared to BOA‐ and TOC‐based films. The findings demonstrate the potential of bio‐based oxetane monomers to produce UV‐curable materials with acceptable thermomechanical properties, offering a sustainable alternative to petroleum‐derived precursors.

This work demonstrates the fabrication of microstructures with formulations containing bio-based prepolymers derived from itaconic acid, commercial reactive diluents, photo initiators, and inhibitors, through two-photon polymerization. Lateral and vertical resolutions within the micron range can be achieved by the adjustment of laser scanning speed and pulse energy, and through the use of microscope objectives with high magnification and numerical aperture. The fabrication throughput can be slightly increased by simultaneously increasing the laser pulse energy and scanning speed, with special care to keep the resolution of the features that can be written via two-photon polymerization. Feasibility for the fabrication of 3D microstructures is demonstrated, through the fabrication of benchmark structures like woodpiles and pyramidal structures. Thus, this work proves that resins based on biobased formulations, originally designed for UV-curing 3D printing, can be adapted for two-photon polymerization, obtaining 3D microstructures with resolutions within the micron range.

Itaconic acid is an attractive biobased feedstock, presenting a bioderived alternative to common monomers such as acrylic acid. Its widespread adoption has been constricted by difficulties in its homopolymerization, which typically requires derivatization or extended reaction times to achieve significant monomer conversion. Here, we report the photoiniferter‐RAFT polymerization of itaconic acid, enabling improved monomer conversion and moderate control over dispersity. Kinetic parameters of homopolymerization are elucidated for a range of monomer concentrations, and the effects of irradiation on the photoiniferter are studied, with loss of end‐group fidelity observed over time. Despite this limitation, the resultant poly(itaconic acid)s have been demonstrated to undergo ω‐terminal labelling, and chain extension with another biosourced monomer, 2‐octyl acrylate, enabling the production of biobased building blocks for solution self‐assembly.

Itaconic acid (IA) is a bio-renewable molecule with increasing industrial availability. However, IA-based polymers have been limited by low molecular weights and conversions. In this work, we report the synthesis...

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Sustainable monomers were designed from itaconic acid and thiolactone. These monomers enabled the preparation of multi-functional polymers according to different pathways.

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Herein, it is reported for the first time that when mixed with choline chloride, itaconic acid (IA), normally a low-reactive vinyl monomer, undergoes initiator-free radical polymerization under normal daylight. Furthermore, the process results in the formation of abnormally high-molecular-weight poly(itaconic acid) derivatives with Mw greater than ≈800 000 g mol-1 . Detailed 1D/2D NMR studies indicate that the polymers have two types of ionizable moieties, that is, anionic carboxylic and cationic choline ester groups in an average molar ratio of 12:1. Potentiometric titration shows polyampholyte behavior of the polymers. Tentative mechanistic studies reveal that the daylight-induced polymerization is initiated by species generated via interactions of near UV light with IA. However, EPR findings show that choline also participates in secondary radical reactions. The obtained polyampholytes are useful bio-based materials for fast and straightforward fabrication of polymer-clay nanocomposite hydrogels with excellent mechanical properties.

This study investigates the emulsifier-free emulsion polymerization of functional copolymer nanoparticles via a free radical mechanism using potassium persulfate (KPS) as the initiator at 70 °C under. The copolymerization involved styrene (S) with either methacrylic acid (MAA), a conventional petrochemical-derived monomer, or itaconic acid (IA), a renewable monomer derived from biomass fermentation. IA exhibited superior water solubility and functionality due to its two carboxylic acid groups per molecule, enhancing polymerization rate and particle stability. The optimal synthesis’s P(S-IA) nanoparticles were achieved using 8 mol % IA with pH adjustment at 30 min after initiation, enabling high solid content preparation while maintaining colloidal stability. It demonstrated significantly improved performance over P(S-MAA) and polystyrene (PS), including complete monomer conversion (∼100%) within 5 h, reduced average particle size (∼200 nm), and minimal coagulation (∼10 wt %) at 30 wt % solid content. In contrast, PS systems exhibited coagulation levels of up to 20% at only 10 wt % solid content, whereas P(S-MAA) presented coagulation levels of up to 38% under similar conditions. These findings highlight the potential of IA-based functional nanoparticles for ion separation and environmental remediation as precursors for hybrid materials in photocatalysis.

The need for the production of synthetic polymers from renewable and sustainable resources also affects the area of emulsion polymerization. The bio-based monomer (BBM) was synthesized from camelina oil (CO) and itaconic acid through transesterification and epoxidation of CO, followed by itaconation, resulting in a blend of methyl esters of CO-originated fatty acids functionalized with reactive methyl itaconate groups. Various amounts of BBM (0−30 wt% of BBM in the total monomer mixture) were copolymerized with standard petroleum-based acrylic monomers (specifically methyl methacrylate, butyl acrylate, and methacrylic acid) using the emulsion polymerization technique to obtain film-forming latexes. Infrared and Raman spectroscopies evidenced the successful incorporation of BBM into the structure of latex polymers. The ultra-high molar mass nanogel fraction was detected by asymmetric flow-field flow fractionation coupled with a multiangle light scattering (AF4-MALS) for the BBM comprising copolymers; the higher the BBM content, the more extensive the nanogel fraction. Cross-linking of latex polymers induced by BBM testified to the reactivity of itaconated functions in emulsion polymerization and provided additional evidence of the copolymerization ability of BBM. The incorporation of BBM also resulted in pendulum hardness and glass transition temperature enhancement (about 11% and 9 °C, respectively, in the case of 30 wt% of BBM content in contrast to 0 wt% of BBM content in the copolymer). Coatings with excellent transparency and gloss were obtained from all latexes regardless of the BBM content used. Slightly increased water repellency (about 7 ° increased water contact angle value) and significantly improved water whitening resistance of the coatings (about 80% decreased water whitening after 1-day long water exposure) were found for coatings comprising 30 wt% of BBM in the copolymer, where the water whitening phenomenon was highly dependent on the BBM content.

The use of flocculants is essential for ensuring the quality of sucrose products. However, the traditional flocculant polyacrylamide (PAM) presents potential safety risks in sucrose production. Biomass-based flocculants have gained much attention due to their abundant availability and environmental benefits, but most of them require high dosages or provide unsatisfactory flocculation results. In this study, an efficient biomass flocculant, sodium alginate grafted itaconic acid (SI) was synthesized by free radical polymerization using the natural polysaccharide sodium alginate (SA) as the base and itaconic acid (IA) as the graft monomer. SI exhibited excellent flocculation performance due to its multi-hollow network structure and high charge (zeta potential of -48.52 mV). Flocculation tests showed that the optimal dosage of SI was 10 ppm (ppm; mg/L), which reduced the color value of sugarcane juice by 66.3 % without causing additional loss of sucrose or reducing sugars. Further analysis revealed that the flocculation mechanism of SI primarily involved charge neutralization and adsorption bridging. In addition, the results showed that SI had advantages in color removal, ease of use and biosafety compared to PAM. This study provides valuable insights into the development of biomass flocculants in the sucrose industry.

A photoinduced reversible addition-fragmentation chain-transfer (photo-RAFT) polymerization technique in the presence of sodium pyruvate (SP) and pyruvic acid derivatives was developed. Depending on the wavelength of light used, SP acted as a biocompatible photoinitiator or promoter for polymerization, allowing rapid open-to-air polymerization in aqueous media. Under UV irradiation (370 nm), SP decomposes to generate CO2 and radicals, initiating polymerization. Under blue (450 nm) or green (525 nm) irradiation, SP enhances the polymerization rate via interaction with the excited state RAFT agent. This method enabled the polymerization of a range of hydrophilic monomers in reaction volumes up to 250 mL, eliminating the need to remove radical inhibitors from the monomers. In addition, photo-RAFT polymerization using SP allowed for the facile synthesis of protein–polymer hybrids in short reaction times (<1 h), low organic content (≤16%), and without rigorous deoxygenation and the use of transition metal photocatalysts. Enzymatic studies of a model protein (chymotrypsin) showed that despite a significant loss of protein activity after conjugation with RAFT chain transfer agents, the grafting polymers from proteins resulted in a 3–4-fold recovery of protein activity.

The bio‐based methacrylates 9‐(methacryloyloxy)‐10,18‐dihydroxyoctadecanoic acid/9,18‐dihydroxy‐10‐(methacryloyloxy)octadecanoic acid isomer mixture and 22‐methacryloyloxydocosanoic acid were synthesized from 9,10‐epoxy‐18‐hydroxyoctadecanoic acid and 22‐hydroxydocosanoic acid. The white crystalline 9,10‐epoxy‐18‐hydroxyoctadecanoic acid and cream‐colored 22‐hydroxydocosanoic acid were isolated from both bark of Betula pendula and cork of Quercus suber after extraction of the milled plant materials with methanol, treating the insoluble residues with 2‐propanole containing suspended sodium hydroxide, application of a working up procedure developed in this work for the resulting mixture, and purification of the products obtained. The new bio‐based methacrylates show higher reactivity in the photoinitiated polymerization in comparison with the commercial laurylmethacrylate as detected by photo‐DSC. For comparison, traditional free radical polymerization of the new bio‐based methacrylates was carried out in dimethylsulfoxide using 2,2’‐azobis‐(2‐propionitrile) as initiator. Furthermore, quantitative conversion of the bio‐based monomers during the photoinitiated polymerization makes these bio‐based monomers interesting for application in coatings. As expected, the photopolymer made from the 9‐(methacryloyloxy)‐10,18‐dihydroxyoctadecanoic acid/9,18‐dihydroxy‐10‐(methacryloyloxy)octadecanoic acid isomer mixture is amorphous. Interestingly, the photopolymer made from the 22‐methacryloyloxydocosanoic acid contains crystalline structures as detected by DSC investigation.This article is protected by copyright. All rights reserved.

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Varnishes are normally applied on printed food packaging to protect it from smearing and scratching. Moreover, they may be applied on the food contact surface in order to improve resistance towards moisture and fat. Some of the compounds that make up the varnish formulation could migrate to the food. In this work, the ion mobility quadrupole time-of-flight mass spectrometry has been used to obtain drift time-aligned mass spectra in which accurate the mass of precursor ions and their fragments are used to identify both intentionally and non-intentionally added substances (NIAS). The compound 2-propenoic acid,1,1'-[2-[[3-[2,2-bis[[(1-oxo-2-propen-1-yl)oxy]methyl]butoxy]-1-oxopropoxy]methyl]-2-ethyl-1,3-propanediyl] ester was identified as a NIAS formed from the varnish monomer 2-propenoic acid, 1,1'-[2-ethyl-2-[[(1-oxo-2-propen-1-yl)oxy]methyl]-1,3-propanediyl] ester. The compound 5, 11-diethyl-7-oxo-4,6,10,12-tetraoxopentadecane-3,13-diyl diacrylate is a NIAS derived from the varnish monomer 2-propenoic acid, 1,1'-[oxybis(methyl-2,1-ethanediyl)] ester, and was found to migrate into the food simulant tested at a level of 0.03 mg kg-1. Finally, the NIAS, 2-{2-[2-(acryloyloxy)-1-methylethoxy]-1-methylethoxy}-1-methylethyl acrylate, an impurity of a photoinitiator used for UV curing of the varnish, was identified, and its migration of 0.14 mg kg-1 exceeded the threshold established as safe for human consumption.

The threat of antibiotic-resistant, biofilm-forming bacteria necessitates a preventative approach to combat the proliferation of robust, pathogenic strains on “high touch surfaces” in the food packaging, biomedical, and healthcare industries. The development of both biocide-releasing and tethered, immobilized biocide surface coatings has risen to meet this demand. While these surface coatings have demonstrated excellent antimicrobial efficacy, there are few examples of antimicrobial surfaces with long-term durability and performance. To this end, UV-curable phosphoniums bearing benzophenone anchors with either an alkyl, aryl, or fluoroalkyl group were synthesized and their efficacy as thermally stable antimicrobial additives in extruded plastics or as surface attached coatings probed. The surface topology and characteristics of these materials were studied to gain insight into the mechanism of their antimicrobial activity. Efficacy against both Gram negative and Gram positive bacteria as either a coating or additive showed compete reductions of the initial bacterial load. Crucially, the materials maintained the ability to kill biofilm-forming bacteria even after being subject to several cycles of abrasion.

In this study, highly transparent siloxane-based hybrid UV-curable coating materials were prepared using (acryloxypropyl)methylsiloxane monomer (APMS), a thiol-ene monomer, with benzoin ethyl ether. For the thiol-ene monomer, either pentaerythritol tetrakis(3-mercaptopropionate) (PETTMP) or trimethylolpropane tris(3-mercaptopropionate) (TMPTMP) was used. The siloxane-based hybrid coating materials were highly transparent and hard (pencil hardness of 6-7H). The materials were also amphiphobic, with a water static contact angle of 92-100° and an oil contact angle of 46-63°, when prepared with a high siloxane-monomer-to-PETTMP/TMPTMP ratio. In general, both hybrid coating materials exhibited improved oleophobicity, high hardness, and surface smoothness with increasing siloxane content, although the TMPTMP-based hybrid coating films exhibited slightly higher oleophobicity (lower hydrophobicity) and a smoother surface than the PETTMP-based hybrid coating films.

The environmental pollution caused by plastic films urgently requires the development of non-toxic, biodegradable, and renewable biopolymer films. However, the poor waterproof and UV resistance properties of biopolymer films have limited their application in fruit packaging. In this work, a novel tannic acid cross-linked chitosan/gelatin film with hydrophobic silica coating (CGTS) was prepared. Relying on the adhesion of tannic acid and gelatin to silica, the coating endows CGTS film with excellent superhydrophobic properties. Especially, the contact angle reaches a maximum value 152.6°. Meanwhile, tannic acid enhanced the mechanical strength (about 36.1 %) through the forming of hydrogen bonding and the network structure. The prepared CGTS films showed almost zero transmittance to ultraviolet light and exhibited excellent radical scavenging ability (∼76.5 %, DPPH). Hence, CGTS film is suitable as a novel multifunctional packaging material for the agriculture to protect premature fruits, or the food industry used in environments exposed to ultraviolet radiation and rainwater.

Active food packaging that provides antioxidant and antimicrobial protection can extend product shelf life, but adding such features to polymers often affects material performance. In this study, we developed a biodegradable poly(butylene adipate-co-terephthalate) (PBAT) film incorporating in situ synthesized tannic acid (TA)/zinc sulfide (ZnS) hybrid nanostructures to add antioxidant, antibacterial, and UV-shielding functions. The TA/ZnS nanohybrids were created using a green in situ co-precipitation method and evenly dispersed in the PBAT matrix to form nanocomposite films. The resulting films showed strong bioactivity, achieving 90.46% DPPH free radical scavenging and inhibition zones over 3.0 cm against both E. coli and S. aureus. They also offered about 97% UV blocking and improved moisture barrier properties, with a 40.9% decrease in water vapor permeability and a 13% increase in water contact angle (surface hydrophobicity). However, these improvements came with roughly a 30% reduction in tensile strength, highlighting a trade-off between added functionality and mechanical performance. Importantly, the composite kept enough flexibility and strength for practical applications. In conclusion, the organic–inorganic synergy between tannic acid and ZnS created a bioactive, UV-protective film that can help extend food shelf life while remaining biodegradable. This green, scalable method shows potential for sustainable next-generation active packaging.

A comprehensive strategy for the analysis of UV-ink photoinitiators and primary aromatic amines (PAAS) in food-packaging materials such as, juice tetrabricks, pouches and bags has been developed using liquid chromatography coupled to Orbitrap High-Resolution Mass Spectrometry (LC-Orbitrap-HRMS). The methodology includes both quantitative target analysis and post-run target screening analysis. The quantitative method was validated after a previous optimisation of the single-stage Orbitrap fragmentation through the Higher-Energy Collisional Dissociation (HCD) Cell. Overall, the quantitative method presented recoveries ranging from 78% to 119%, with a precision (RSD) lower than 20%, for the 18 substances in the scope of the target method. Limit of quantification (LOQ) for UV-inks photoinitiators ranged from 0.5 µg/kg-1 for Isopropyl Thioxanthone (ITX) and 2-Ethylhexyl 4-(dimethylamino) benzoate (EHDAB) to 5 µg/kg-1 for the rest of photoinitiators. LOQ for PAAs were 2 µg/kg-1 except for aniline (ANL) and 3,3' dimethylbenzidine (3,3'-DMB) which was 2.5 µg/kg-1 in the two studied simulants (acetic acid 3% and ethanol 50%). For post-run target screening a customized theoretical database, that included Bisphenols, Polyfluorinated compounds (PFCs), Phosphorus Flame Retardants (PFRs) and other substances was built. For identification purposes, a mass accuracy lower than 5 ppm, and some diagnostic ions including isotopes and/or fragments were used. The strategy was applied to 18 samples collected in the Valencian region (Spain). No compounds were detected when the standardised migration test was applied. However, in the destructive test, benzophenone and EHDAB were determined from tetrabrick and pouch materials. In the post-run target analysis two PFCs (Perfluorooctanoic acid and Perfluoro-1-butanesulfonate) and four PFRs (2-ethylhexyl diphenyl phosphate, tris(2-choloroisopropyl) phosphate, triphenyl phosphate and 2-ethylhexyl diphenyl phosphate) were identified.

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UV-curable inks, coatings, and adhesives are being increasingly used in food packaging systems. When exposed to UV energy, UV-photoinitiators (PI’s) present in the formulations produce free radicals which catalyze polymerization of monomers and pre-polymers into resins. In addition to photopolymerization, other free radical reactions occur in these systems resulting in the formation of chemically varied photolytic decomposition products, many of which are low molecular weight chemical species with high migration potential. This research conducted model experiments in which 24 commonly used PI’s were exposed to UV-energy at the typical upper limit of commercial UV-printing press conditions. UV-irradiated PI’s were analyzed by gas chromatography-mass spectrometry (GC-MS) and electrospray-mass spectrometry (ESI-MS) in order to identify photolytic decomposition products. Subsequently, migration studies of 258 UV-cure food packaging samples were conducted using GC-MS; PI’s and photolytic decomposition products were found in nearly all samples analyzed. One hundred-thirteen photolytic decomposition products were identified. Eighteen intact PI’s and 21 photolytic decomposition products were observed as migrants from the 258 samples analyzed, and these were evaluated for frequency of occurrence and migratory concentration range. The most commonly observed PI’s were 2-hydroxy-2-methylpropiophenone and benzophenone. The most commonly observed photolytic decomposition products were 2,4,6-trimethylbenzaldehyde and 1-phenyl-2-butanone. This compilation of PI photolytic decomposition data and associated migration data will aid industry in identifying and tracing non-intentionally added substances (NIAS) in food packaging materials.

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Reducing photoinitiator migration from photocured coatings remains a critical challenge, particularly for applications in food packaging and healthcare products. Here, we report a series of novel UV-LED sensitive oxime ester photoinitiators that possess self-anchoring ability through incorporating polymerizable double bonds into the coumarin chromophore. All photoinitiators exhibit strong absorption around 340 nm and efficient photolysis under 365 nm LED irradiation, showing good initiating efficiency in acrylates and thiol-ene formulations. Migration studies show that the incorporation of polymerizable groups at the oxime ester terminus reduces the migration rate of the residual photoinitiator from 81% to 16.3%, while introducing an allyl group into the coumarin structure further decreases it to 5% and potentially suppresses the migration of low-molecular-weight photolysis products. The dual-functionalized derivative achieves the lowest migration rate of 3%. This molecular design strategy provides an effective approach toward safe UV-LED curable coatings with minimal photoinitiator migration.

Paper-based packaging can offer a sustainable replacement for plastics. However, paper provides a poor barrier to water, oxygen and moisture. This study presents a novel renewable lignocellulosic composite made from a hydrophobic photo-reversible coating deposited onto a cellulose nanofiber film that has improved barrier properties and can be reprocessed. Diglycerol and lignin-derivable aldehyde were reacted to form a tetra-functional monomer with photo-responsive unsaturated double bonds that can be converted to covalent cyclobutane rings to create reversibly crosslinkable network upon UV-irradiation. The photo-responsive compound was applied as a thin coating of thickness 2.7±0.4 μm over cellulose nanofiber (CNF) films of thickness 80±19 μm. The surface of the coated films became hydrophobic with a contact angle (CA) of 93.1±1.7° and displayed a low water vapour transmission rate (WVTR) of 16±2 g/m2/day vs. 30.7±1.5° CA and 81±11 g/m2/day WVTR for uncoated CNF films. The coated film is also oleophobic, an attractive feature for food packaging applications. The reversible photo-reaction enables the crosslinked covalent network to be broken down to unsaturated double bonds once exposed to a higher-energy UV irradiation, allowing reprocessing and recycling. The novel coating was developed using a sustainable green synthesis method (process simple E factor 0.9).

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Hierarchical cation-exchange membranes (hCEMs) fabricated by blade coating and UV crosslinking of ionomer on top of a porous substrate demonstrated promising results in performing NaCl demineralization. In the food industry, complex solutions are used and hCEMs were never investigated before for these food applications. The performances of two different coating chemistries (urethane acrylate based: UL, and acrylic acid based: EbS) and three crosslinking degrees (UL5, UL6, UL7 for UL formulations, and EbS-1, EbS-2, EbS-3 for EbS formulations) were formulated. The impacts of hCEMs properties and crosslinking density on whey demineralization performances by electrodialysis (ED) were evaluated and compared to CMX, a high performing CEM for whey demineralization by ED. The crosslinking density had an impact on the hCEMs area specific resistance, and on the ionic conductance for EbS membrane. However, 70% demineralization of 18% whey solution was reached for the first time for hCEMs without any fouling observed, and with comparable performances to the CMX benchmark. Although some properties were impacted by the crosslinking density, the global performances in ED (limiting current, demineralization duration, global system resistance, energy consumption, current efficiency) for EbS and UL6 membranes were similar to the CMX benchmark. These promising results suggest the possible application of these hCEMs (UL6, EbS-2, and EbS-3) for whey demineralization by ED and more generally complex products as an alternative in the food industry.

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Bacterial susceptibility testing and real-time inactivation are critical for safeguarding public health with broad applications in food safety monitoring and clinical diagnostics. For pH-dependent bacterial determination and hyperthermal inactivation applications, we developed needle-shaped ZnO/ZIF-L systems through a zeolitic imidazolate framework coating of zinc oxide by a self-template strategy. The pH-dependent ZnO/ZIF-L-embedded hydrogels were prepared by UV light-mediated olefin photopolymerization using acrylamide, N,N'-methylenebis(acrylamide), hydroxyethyl methacrylate, bromothymol blue (BTB), and ZnO/ZIF-L. The hydrogel achieves rapid visual detection of bacterial infections through a pH-responsive colorimetric transition, leveraging BTB to signal acidic microenvironmental shifts characteristic of bacterial proliferation. The ZnO/ZIF-L photosensitizers can enhance charge separation and transfer and generate highly reactive oxygen species. Escherichia coli and Staphylococcus aureus can be effectively inactivated for ZnO/ZIF-L hydrogels by a physical disruption/photodynamic synergistic antibacterial mechanism. The antibacterial efficiency can reach as high as 99%. The proposed strategy not only provides a sensitive strategy for bacterial determination but also implements efficient inactivation of bacteria simultaneously. This strategy combines real-time bacterial biosensing with on-demand antimicrobial action in a single platform, overcoming the limitations of conventional sequential detection-treatment approaches.

Traditional photosensitive polyimide (PSPI) materials require a high curing temperature and exhibit low transparency, limiting their applications in thermally sensitive optical devices. To overcome this challenge, soluble photosensitive polyimide resins were synthesized based on the structural design of a bio-based magnolol monomer. It is noteworthy that the PI photoresist, developed by using the as-prepared polyimides and non-toxic solvents (2-acetoxy-1-methoxypropane, PGEMA) and other additives, demonstrated an impressive low-temperature curing performance (180 °C). Furthermore, the solvent residue in the cured film prepared using PGEMA as solvent was markedly decreased compared to that prepared using N-methyl pyrrolidone (NMP). In addition, the C-PI-3 films cured by photoinitiated thiol–ene radical reactions exhibited high transparency with an average visible light transmittance of 87.8%, as well as excellent thermal stability, dielectric and breakdown properties, and photo-patterning capabilities. This partially bio-based and innocuous solvent-based PSPI with low-temperature curability and high transparency properties could be a pioneering example to resolve the challenges of energy efficiency and environmental sustainability and is expected to be used in the field of color filters.

Abstract Home fragrance (F) products such as laundry detergent and fabric softener use fragrance or essential oils as key components. Typically, the fragrance is enclosed within a polymer. The shell enhances the longevity of the scent due to its durability. However, there is growing environmental concern about utilizing fossil polymers, which decompose slowly and harm the ecology and food chain. Biopolymers are also highly expected to be used as alternative polymers to prepare environmentally friendly microcapsules. This research aims to use poly cinnamyl methacrylate (PCMA) as a biopolymer to prepare microcapsules encapsulated fragrance via interfacial photo-initiated crosslinking. The CMA monomer was prepared by the esterification of cinnamyl alcohol with methacrylic anhydride and synthesized via radical polymerization to form PCMA with a molecular weight of 6,400 g/mol. The PCMA and PCMA/F particles were obtained when the PCMA and PCMA/F droplets dispersed in water were UV-irradiated at 60 W for 8h, giving PCMA and PCMA/F particles contained the highest crosslinking (60–75%). Both PCMA and PCMA/F particles were spherical and smooth outer surfaces where their particle sizes of ∼2 and 7 µm for PCMA and PCMA/F particles were obtained, respectively. The larger size of PCMA/F particles was due to encapsulation, where the encapsulation efficiency of fragrance in PCMA/F particles was approximately 100%. Moreover, the fragrances remaining in the microcapsule particles after 40 days of storage were over 90%. This technique was simple, had high potential microencapsulation, and was environmentally friendly, so the developed microcapsules would express great potential for textiles and laundry formulations. Graphical Abstract

ABSTRACT In response to environmental concerns and restrictions on isocyanate-based materials, researchers and the coatings industry are focused on developing eco-friendly isocyanate-free polyurethanes. This article introduces a novel class of environmentally-friendly, initiator/catalyst-free, UV-curable, self-healing non-isocyanate polyurethanes (NIPUs) synthesized from bio-based carbonated soybean oil (CSO) and non-toxic coumarin. The synthesis of these polymers is based on using a photo-reactive coumarin that undergoes a reversible [2 + 2] cycloaddition upon exposure to the wavelength of UV light. UV-curable three coumarin-terminated isocyanate-free polyurethane prepolymers were synthesized using CSO and three different amines and epoxy coumarin. Subsequently, a set of cross-linked NIPU polymers were obtained with exposure of 365 nm UV irradiation. The photo-reversible nature of these polymers was investigated in response to various wavelengths of UV radiation. Additionally, their self-healing ability and the thermal and mechanical properties of NIPU coatings were studied using optical microscopy, thermogravimetric analysis, differential scanning calorimetry, and a universal testing machine. The outcomes demonstrate that this polyurethane has the potential to provide a sustainable alternative to isocyanate-based materials. Two examples of stimulated healing are given, that of healing a scratch and the other being the healing of a sample that has been mechanically stressed to failure in a tensile mode. GRAPHICAL ABSTRACT

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Biopolymer composite materials were prepared by combining bio-sourced cationic water-soluble chitosan with bi-functional water-soluble anionic azo food dyes amaranth (AMA) or allura red (ALR) as ionic cross-linkers, mixing well in water, and then slow-drying in air. The electrostatically-assembled ionically-paired films showed good long-term stability to dissolution, with no re-solubility in water, and competitive mechanical properties as plastic materials. However, upon exposure of the bioplastics to low power light at sunlight wavelengths and intensities stirring in water, the stable materials photo-disassembled back to their water-soluble and low-toxicity (edible) constituent components, via structural photo-isomerization of the azo ionic crosslinkers. XRD, UV-vis, and IR spectroscopy confirmed that these assemblies are reversibly recoverable and so can in principle represent fully recyclable, environmentally degradable materials triggered by exposure to sunlight and water after use, with full recovery of starting components ready for re-use. A density functional theory treatment of the amaranth azo dye identified a tautomeric equilibrium favouring the hydrazone form and rationalized geometrical isomerization as a mechanism for photo-disassembly. The proof-of-principle suitability of films of these biomaterial composites as food industry packaging was assessed via measurement of mechanical, water and vapour barrier properties, and stability to solvent tests. Tensile strength of the composite materials was found to be 25–30 MPa, with elongation at break 3–5%, in a range acceptable as competitive for some applications to replace oil-based permanently insoluble non-recyclable artificial plastics, as fully recyclable, recoverable, and reusable low-toxicity green biomaterials in natural environmental conditions.

Increased environmental awareness has led to a demand for sustainable, bio-based materials. Consequently, the development of new benign synthesis pathways utilizing a minimum of reaction steps and available bio-based building blocks is needed. In the present study, vinyl ether alcohols and functional carboxylic acids were used to synthesize bifunctional vinyl ether esters using the immobilized enzyme Candida antarctica lipase B as a catalyst. Vinyl ethers are attractive alternatives to (meth)acrylates due to low allergenic hazards, low toxicity, and fast polymerization; however, difficult synthesis limits the monomer availability. The synthesis was performed in one-pot and the described method was successful within a broad temperature range (22–90 °C) and in various organic solvents as well as in the bulk. The synthesis of different vinyl ether esters reached high conversions (above 90%) after less than 1 h and products were purified by removing the enzyme by filtration using only small amounts of acetone. This approach is a straightforward route to reach monomers with multiple types of functionalities that can be used as different photo-curable thermoset resins. In this work, this was demonstrated by polymerizing the monomers with cationic and radical UV-polymerization. By changing the functional carboxylic acids, the architecture of the final polymer can be tailored, herein demonstrated by two examples. In the developed versatile method, carboxylic acids can be used directly as acyl donors, constituting a more sustainable alternative to the carboxylic acid derivatives used today.

Hair is continuously exposed to various damaging factors in daily life, necessitating effective protective strategies that balance efficacy with environmental sustainability. In this study, we developed an environmentally friendly hair protective coating using casein proteins crosslinked with tannic acid via riboflavin phosphate-mediated photo-initiation. Casein solutions containing tannic acid (0.05% w/v) and riboflavin phosphate (0.01–0.1% w/v) were prepared and applied to virgin Asian hair, followed by blue light irradiation to initiate crosslinking. The coating formation mechanism was investigated through rheological characterization, which confirmed successful network formation with optimal mechanical stability at a 0.05% tannic acid concentration. Chemical analysis using FTIR spectroscopy revealed subtle but meaningful interactions between the coating components, while SEM analysis demonstrated the coating’s integration with the hair surface. Mechanical property evaluations showed that the photo-crosslinked coating significantly enhanced hair tensile strength by approximately 21% compared to untreated hair, while maintaining appropriate elasticity. Region-specific analysis of stress–strain behavior indicated that the coating extended the initial Hookean region while preserving natural resistance in the post-yield region, creating a balanced enhancement in mechanical properties. This approach offers a promising alternative to conventional hair treatments by utilizing natural, food-grade components and mild processing conditions, addressing growing demands for sustainable hair care solutions that effectively protect against daily damage.