Soluble Fluorinated Cardo Copolyimide as an Effective Additive to Photopolymerizable Compositions Based on Di(meth)acrylates: Application for Highly Thermostable Primary Protective Coating of Silica Optical Fiber.

The development of photocurable compositions is in high demand for the manufacture of functional materials for electronics, optics, medicine, energy, etc. The properties of the final photo-cured material are primarily determined by the initial mixture, which needs to be tuned for each application. In this study we propose to use simple systems based on di(meth)acrylate, polyimide and photoinitiator for the preparation of new photo-curable compositions. It was established that a fluorinated cardo copolyimide (FCPI) based on 2,2-bis-(3,4-dicarboxydiphenyl)hexafluoropropane dianhydride, 9,9-bis-(4-aminophenyl)fluorene and 2,2-bis-(4-aminophenyl)hexafluoropropane (1.00:0.75:0.25 mol) has excellent solubility in di(met)acrylates. This made it possible to prepare solutions of FCPI in such monomers, to study the effect of FCPI on the kinetics of their photopolymerization in situ and the properties of the resulting polymers. According to the obtained data, the solutions of FCPI (23 wt.%) in 1,4-butanediol diacrylate (BDDA) and FCPI (15 wt.%) in tetraethylene glycol diacrylate were tested for the formation of the primary protective coatings of the silica optical fibers. It was found that the new coating of poly(BDDA-FCPI23%) can withstand prolonged annealing at 200 °C (72 h), which is comparable or superior to the known most thermally stable photo-curable coatings. The proposed approach can be applied to obtain other functional materials.

Environmental implications and nanotechnological advances in octocrylene-enriched sunscreen formulations: A comprehensive review.

Ultraviolet (UV) radiation is a major contributor to skin aging, cancer, and other detrimental health effects. Sunscreens containing FDA-approved UV filters, like avobenzone, offer protection but suffer from photodegradation and potential phototoxicity. Encapsulation, antioxidants, and photostabilizers are strategies employed to combat these drawbacks. Octocrylene, an organic UV filter, utilizes nanotechnology to enhance sun protection factor (SPF). This review examines recent literature on octocrylene-enriched sunscreens, exploring the interplay between environmental impact, nanotechnological advancements, and clinical trial insights. A critical focus is placed on the environmental consequences of sunscreen use, particularly the potential hazards UV filters pose to marine ecosystems. Research in the Mediterranean Sea suggests bacterial sensitivity to these filters, raising concerns about their integration into the food chain. This review aims to guide researchers in developing effective strategies for photostabilization of UV filters. By combining encapsulation, photostabilizers, and antioxidants, researchers can potentially reduce phototoxic effects and contribute to developing more environmentally friendly sunscreens.

Design and preparation of reticular superabsorbent hydrogel material with nutrient slow-release and high shear strength for ecological remediation of abandoned mines with steep slopes.

In order to solve ecological remediation issues for abandoned mines with steep slopes, a kind of hydrogels with high cohesion and water-retaining were designed by inorganic mineral skeleton combining with polymeric organic network cavities. This eco-friendly hydrogel (MFA/HA-g-p(AA-co-AM)) was prepared with acrylic acid (AA)-acrylamide (AM) as network, which was grafted with humic acids (HA) as network binding point reinforcement skeleton and polar functional group donors, KOH-modified fly ash (MFA) as internal supporter. The maximum water absorption capacities were 1960 g/g for distilled water, which followed the pseudo-second-order model. This super water absorption was attributed to the first stage of 62 % fast absorption due to the high specific surface area, pore volume and low osmotic pressure, moreover, the multiple hydrophilic functional groups and network structure swell contributed to 36 % of the second stage slow adsorption. In addition, the pore filling of water in mesoporous channels contributed the additional 2 % water retention on the third stage. The high saline-alkali resistance correlated with the electrostatic attraction with MFA and multiple interactions with oxygen-containing functional groups in organic components. MFA and HA also enhanced the shear strength and fertility retention properties. After 5 cycles of natural dehydration and reabsorption process, these excellent characteristics of reusability and water absorption capacity kept above 97 %. The application of 0.6 wt% MFA/HA-g-p(AA-co-AM) at 15° slope could improve the growth of ryegrass by approximately 45 %. This study provides an efficient and economic superabsorbent material for ecological restoration of abandoned mines with steep slopes.

Effect of oxygen-containing functional group contents on sorption of lead ions by acrylate-functionalized hydrochar.

The surface functional groups of hydrochar are crucial to its surface properties, and their contents are strongly positively correlated with the adsorption performance. In this study, acrylate-functionalized hydrochar (AHC) with varying contents of O-containing functional groups (OFGs) was synthesized via hydrothermal carbonization (HTC) of bamboo, acrylic acid and an initiator, and then deprotonated with NaOH. The AHCs were analyzed by various characterization techniques. During HTC, the higher amount of acrylic acid added led to higher carbon, oxygen and carboxyl contents, and to the larger specific surface area and pore volume of AHC. The adsorption kinetics, isotherms, thermodynamic, ionic strength and pH effects of Pb(II) on AHC were studied. Adsorption isotherms and kinetics obeyed Langmuir and pseudo-second-order models, respectively, indicating adsorption is monolayer chemical process. The adsorptive ability was well linearly related to the OFG contents of AHC. When acrylic acid was added to 25 mL during HTC, the adsorbing ability of AHC over Pb(II) reached 193.90 mg g-1. Hence, direct HTC of acrylic acid, biomass and an initiator can prepare hydrochar with controllable OFG contents, which is a prospective adsorbent for treating metal cations.

Synthesis of ultrathin hybrid membranes via the co-polymerization of acrylic acid, styrene and molybdenum disulfide and their high adsorption selectivity for lead(II) in the mixture of metal ions.

Lead(II) is a potential carcinogen of heavy-metal ions (HIs). With the wide application of Pb-bearing products including lead alloy products, and new-energy lead-ion batteries, lead pollution has become a tricky problem. To solve such a difficulty, novel ultrathin MoS2-vinyl hybrid membranes (MVHMs) with a "spring" effect were synthesized via co-polymerization of acrylic acid, styrene and molybdenum disulfide (MoS2) and their adsorptions for HIs were explored. The "spring" effect derived from the interaction between the tendency of the short polyacrylic acid (PAA) chain connected with MoS2 to spread outward and the coulomb force between layers from MoS2 (s-MoS2), which enlarge the spacing of MoS2 layers without changing the number of layers after membrane formation, which changes the swelling membrane to a dense membrane and reduces the original thickness from 0.5 cm to 0.011 mm in the thickness direction. The adsorption experiment revealed that these MVHMs had super adsorption performance and high selectivity for Pb2+ by comparison with other five metal ions: Cu2+, Cd2+, Ni2+, Cr3+ and Zn2+. Especially, the adsorption quantity of MVHMs for Pb2+ could approach 2468 mg/g and the maximum adsorption ratio of qe[Pb2+]/qe[Cu2+] can reach 10.909. These values were much larger than the data obtained with the adsorbents reported in the last decade. A variety of models are applied to evaluate the effect of ionic groups. It was confirmed that -COOH plays a key role in adsorption of HIs and s-MoS2 also has a certain contribution. Conversely, ion exchange plays only a minor role during the period of adsorption process. Effective diffusion coefficient (Deff) of Pb(II) had the largest values among these metal ions. Hence, these hybrid membranes are promising adsorbents for the removal of Pb2+ from water containing various ions.

A comparative study of the in vitro dermal absorption of radiolabeled benzophenone through human skin.

Octocrylene is a common sun filter ingredient used to protect the skin from damaging UV rays. Benzophenone is an impurity found in formulations containing octocrylene. [14C]-Benzophenone was spiked (0.1 g/L) into 2 commercial sunscreen formulations; Neutrogena® Beach Defense Sunscreen Spray Broad Spectrum SPF 70 Aerosol, Neutrogena® Ultra Sheer Body Mist Sunscreen Broad Spectrum SPF 30 Aerosol, and an acetone vehicle. The formulations were applied (ca 2 µL/cm2) to dermatomed human skin mounted in static diffusion cells in vitro. Receptor fluid was collected up to 24 h post dose. All samples were analyzed by liquid scintillation counting. The dermal delivery of [14C]-Benzophenone was 10.02, 9.04 and 5.19% for the 3 formulations. However, the [14C]-Benzophenone mass balances were low; 81.5, 85.3 and 8.02%, respectively. A volatility test was performed replacing skin with aluminum foil for the sunscreen formulations only. The [14C]-Benzophenone mass balance at dosing was 99% but fell to 56.9 and 60.6% at 24 h post dose, confirming the losses were due to [14C]-Benzophenone volatility. A conservative dermal absorption value of 12.42% was proposed to cover [14C]-Benzophenone containing formulations.

Enhanced sun protection factor of octocrylene with green tea and bhringraj extracts.

OBJECTIVES: The aim of this study of sun protection factor boosting effect sunscreen compositions with herbal extract and combination with octocrylene. MATERIALS AND METHODS: The standardized herbal extracts procured and studied their sun protection Factors. Camellia Sinensis (Green tea) leaf Extract, Eclipta prostrata (bhringraj) leaf extract are selected for the development of the herbal sunscreen composition along with octocrylene as synthetic sunscreen. The developed sunscreen composition contains defined concentration of herbal extracts and octocrylene were evaluated for their different physicochemical properties and stability. Sun protection factor boosting effect of herbal extracts is studied combination with octocrylene. RESULTS: Invitro SPF studied for herbal extract individually and combination with octocrylene. The results of Invitro SPF study revealed the presence of green tea extract and, Eclipta prostrata (bhringraj) leaf extract shows excellent sun protection factor (SPF) boosting value of sunscreen composition containing 5% concentration of herbal extract and octocrylene. The sunscreen formulation containing 5% herbal extracts are stable for 12 weeks in an oven (45 °C). CONCLUSION: The findings of this in-vitro SPF study revealed a sun protection boosting capacity of green tea extract and bhringraj extract confirmed. SUMMARY: The over exposure of human skin to Ultra-Violet Radiation (UVR) can trigger photodamage, UV burn, pigmentation, erythema, and enhance the chance of dermal carcinoma. UVR causes DNA damage, which leads to dermal cancer. Daily sunscreens protect the skin from the adverse effects of sun rays, especially UVB (290-320 nm) and UVA (320-400 nm). The ozone layer filters UVC (200-290 nm) radiation when it enters into atmosphere of the earth. UVB causes sunburn, photo damage and cause mutagenic changes in nucleic acids. UVA increases ROS (Reactive Oxygen Species) accumulation. ROS is responsible for cell repair which leads to carcinogenesis, and the cause of photodamage. Herbal extracts contain polyphenols, and flavonoids act as a natural sunscreen that will filter Ultra-Violet (UVB) light and contain antioxidant characteristics to modulate the photo-oxidative damage that results from UV-induced Reactive Oxygen Species production. The UVR protection of most herbal extracts are required to attain the higher UV protection in the sun care products. The approaches for preparing sun care products with higher Sun Protection Factor (SPF) possible through Oil in water formulation with herbal extract combinations of octocrylene. The developed sunscreen composition containing different concentration of herbal extracts were evaluated for their other physicochemical properties and stability. Invitro SPF was studied for Camellia Sinensis (Green tea) Leaf Extract and Eclipta prostrata (bhringraj) leaf extract individually and in combination with octocrylene. The results of the Invitro SPF study revealed the Camellia Sinensis (Green tea) Leaf Extract with octocrylene shows better Sun protection factor than Eclipta prostrata (bhringraj) leaf extract with octocrylene. The Sun Protection Factor (SPF) enhancement value of sunscreen compositions was compared to both sunscreen macroemulsion and nanoemulsion.

Water-compatible cross-linked pyrrolidone acrylate pressure-sensitive adhesives with persistent adhesion for transdermal delivery: Synergistic effect of hydrogen bonding and electrostatic force.

Poor skin adhesion and mechanical properties are common problems of pressure-sensitive adhesive (PSA) in transdermal drug delivery system (TDDS). Its poor water compatibility also causes the patch to fall off after sweating or soaking in the application site. To solve this problem, poly (2-Ethylhexyl acrylate-co-N-Vinyl-2-pyrrolidone-co-N-(2-Hydroxyethyl)acrylamide) (PENH), a cross-linked pyrrolidone polyacrylate PSA, was designed to improve the adhesion and water resistance of PSA through electrostatic force and hydrogen bonding system. The structure of PENH was characterized by 1H NMR, FTIR, DSC, and other methods. The mechanism was studied by FTIR, rheological test, and molecular simulation. The results showed that the PENH patch could adhere to human skin for more than 10 days without cold flow, and it could still adhere after sweating or water contact. In contrast, the commercial PSA Duro-Tak® 87-4098 and Duro-Tak® 87-2852 fell off completely on the 3rd and 6th day, respectively, and Duro-Tak® 87-2510 showed a significant dark ring on the second day. Mechanism studies have shown that the hydrogen bond formed by 2-ethylhexyl acrylate (2-EHA), N-vinyl-2-pyrrolidinone (NVP), and N-(2-Hydroxyethyl)acrylamide (HEAA) enhances cohesion, the interaction with skin improves skin adhesion, and the electrostatic interaction with water or drug molecules enhances the ability of water absorption and drug loading. Due to the synergistic effect of hydrogen bonds and electrostatic force, PENH can maintain high cohesion after drug loading or water absorption. PENH provides a choice for the development of water-compatible patches with long-lasting adhesion. STATEMENT OF SIGNIFICANCE: Based on the synergistic effect of hydrogen bonding and electrostatic force, a hydrogen-bonded, cross-linked pyrrolidone acrylate pressure-sensitive adhesive for transdermal drug delivery was designed and synthesized, which has high adhesion and cohesive strength and is non-irritating to the skin. The patch can be applied on the skin surface continuously for more than 10 days without the phenomenon of "dark ring", and the patch can remain adherent after the patient sweats or bathes. This provides a good strategy for choosing a matrix for patches that require prolonged administration.

Block Copolymers of Polyolefins with Polyacrylates: Analyzing and Improving the Blocking Efficiencies Using MILRad/ATRP Approach.

Despite their industrial ubiquity, polyolefin-polyacrylate block copolymers are challenging to synthesize due to the distinct polymerization pathways necessary for respective blocks. This study utilizes MILRad, metal-organic insertion light-initiated radical polymerization, to synthesize polyolefin-b-poly(methyl acrylate) copolymer by combining palladium-catalyzed insertion-coordination polymerization and atom transfer radical polymerization (ATRP). Brookhart-type Pd complexes used for the living polymerization of olefins are homolytically cleaved by blue-light irradiation, generating polyolefin-based macroradicals, which are trapped with functional nitroxide derivatives forming ATRP macroinitiators. ATRP in the presence of Cu(0), that is, supplemental activators and reducing agents , is used to polymerize methyl acrylate. An increase in the functionalization efficiency of up to 71% is demonstrated in this study by modifying the light source and optimizing the radical trapping condition. Regardless of the radical trapping efficiency, essentially quantitative chain extension of polyolefin-Br macroinitiator with acrylates is consistently demonstrated, indicating successful second block formation.

Facile fabrication of cellulose-based hydrophobic paper via Michael addition reaction.

The inherent highly hydrophilic feature of cellulose-based paper hinders its application in many fields. Herein, a cellulose-based hydrophobic paper was fabricated based on surface chemical modification. Firstly, the hydrophobic acrylate components were bonded to the cellulose acetoacetate (CAA) fibers to obtain CAA graft acrylate (CAA-X) fibers through Michael addition reaction. Subsequently, CAA-X fibers were processed into paper via wet papermaking technology. The resulting paper exhibited good hydrophobic performance (water contact angle was up to 135°) with an air permeability of 24.8 µm/Pa·s. The hydrophobicity of paper was very stable and remained even after treating with different solvents. Moreover, the hydrophobic properties of this paper could be adjusted by changing the type of acrylate component. It should be noted that the surface modification strategy has no obvious effects on the whiteness (79.8%), writing, and printing properties of the cellulose fibers. Thus, it is a simple, benign, and efficient strategy for the construction of cellulose-based hydrophobic paper, which has great potential to be used in paper tableware, oil-water separation, watercolor protection, and food packaging fields.

Photo Fenton RAFT Polymerization of (Meth)Acrylates in DMSO Sensitized by Methylene Blue.

A novel open-to-air photo RAFT polymerization of a series of acrylate and methacrylate monomers mediated by matching chain transfer agent irradiated by far-red light in DMSO is reported. Hydroxyl radical (•OH) generated from methylene blue (MB) sensitized decomposition of H2 O2 via photo-Fenton like-reaction is used for polymerization initiation. The "living/control" characteristic is evidenced by kinetic study, in which a pseudo first order curve and linearly increases of molecular weight with the increase of monomer conversion are observed. The living end-group fidelity is characterized by MALDI-TOF-MS and 1 H NMR results, and confirmed by successful chain extension. The temporary controllability is proved by light on/off switch experiment.

Influence of Molecular Structures of Organic Foulants on the Antifouling Properties of Poly(2-methoxyethyl acrylate) and Its Analogs: A Molecular Dynamics Study.

Elucidating the fouling phenomena of polymer surfaces will facilitate the molecular design of high-performance biomedical devices. Here, we investigated the remarkable antifouling properties of two acrylate materials, poly(2-methoxyethyl acrylate) (PMEA) and poly(3-methoxypropionic acid vinyl ester) (PMePVE), which have a terminal methoxy group on the side chain, via molecular dynamics simulations of binary mixtures of acrylate/methacrylate trimers with n-pentane or 2,2-dimethylpropane (neopentane), that serve as the nonpolar organic probe (organic foulants). The second virial coefficient (B2) was determined to assess the aggregation/dispersion properties in the binary mixtures. The order of the B2 values for the trimer/pentane mixtures indicated that the terminal methoxy group of the side chain plays an important role in enhancing the fouling resistance to nonpolar organic foulants. Here, we hypothesized that the antifouling properties of PMEA/PMePVE surfaces originate from the resistance. To evaluate the molecular-level accessibility of organic foulants to acrylate/methacrylate materials, we examined the radial distribution functions (RDFs) of the terminal methyl groups of neopentane around the main chains of the acrylate/methacrylate trimers. As a result, the third distinct RDF peaks are observed only for the methacrylate trimers. The peaks are attributed to the hydrophobic interactions between the methyl group of neopentane and that of the main chain of the trimer. Accordingly, the methyl group of the main chain of methacrylate materials, such as poly(2-hydroxyethyl methacrylate) and poly(2-methoxyethyl methacrylate), unfavorably induces fouling with organic foulants. In this study, we clarify that preventing hydrophobic interactions between an organic foulant and polymeric material is essential for enhancing the antifouling property. Our approach has great potential for evaluating the molecular-level affinities of organic foulant with polymer surfaces for the molecular design of excellent antifouling polymeric materials.

Thiol-Michael Addition Microparticles: Their Synthesis, Characterization, and Uptake by Macrophages.

Polymeric microparticles are promising biomaterial platforms for targeting macrophages in the treatment of disease. This study investigates microparticles formed by a thiol-Michael addition step-growth polymerization reaction with tunable physiochemical properties and their uptake by macrophages. The hexafunctional thiol monomer dipentaerythritol hexa-3-mercaptopropionate (DPHMP) and tetrafunctional acrylate monomer di(trimethylolpropane) tetraacrylate (DTPTA) were reacted in a stepwise dispersion polymerization, achieving tunable monodisperse particles over a size range (1-10 µm) relevant for targeting macrophages. An off-stoichiometry thiol-acrylate reaction afforded facile secondary chemical functionalization to create particles with different chemical moieties. Uptake of the microparticles by RAW 264.7 macrophages was highly dependent on treatment time, particle size, and particle chemistry with amide, carboxyl, and thiol terminal chemistries. The amide-terminated particles were non-inflammatory, while the carboxyl- and thiol-terminated particles induced pro-inflammatory cytokine production in conjunction with particle phagocytosis. Finally, a lung-specific application was explored through time-dependent uptake of amide-terminated particles by human alveolar macrophages in vitro and mouse lungs in vivo without inducing inflammation. The findings demonstrate a promising microparticulate delivery vehicle that is cyto-compatible, is non-inflammatory, and exhibits high rates of uptake by macrophages.

Visible Light Induced Degradation of Poly(methyl methacrylate-co-methyl α-chloro acrylate) Copolymer at Ambient Temperature.

Poly(methyl methacrylate) (PMMA) is a well-known and widely used commodity plastic. High production amount of PMMA causes excessive waste creation that highlights the necessity of recycling. Conventional recycling methods require elevated temperatures to induce degradation or depolymerization. In this work, visible light induced photodegradation system by using dimanganese decacarbonyl (Mn2 (CO)10 ) with high halogen affinity is reported. Halide functional photodegradable polymers are prepared by copolymerization of methyl methacrylate and methyl α-chloroacrylate by conventional reversible addition-fragmentation chain-transfer polymerization. Synthesized copolymers are efficiently degraded to low molecular weight oligomers under visible light irradiation in the presence of Mn2 (CO)10 . Characteristics of precursors, degraded polymers, and kinetics of depolymerization are investigated by gel permeation chromatography (GPC), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourrier transform infrared (FTIR), and proton nuclear magnetic resonance (1 H-NMR) spectroscopies. The reported approach is expected to trigger further development of more environmentally friendly recycling techniques in the near future as we  are moving toward a greener and more sustainable world.

Poly(carboxyethyl acrylate-co-ethylene glycol dimethacrylate) precursor monolith with bonded Tris ligands for use in hydrophilic interaction capillary electrochromatography.

The facile preparation of a monolithic capillary column with surface bound polar ligands for use in hydrophilic interaction capillary electrochromatography is described. It involved the conversion of poly(carboxyethyl acrylate[CEA]-co-ethylene glycol dimethacrylate[EDMA]) precursor monolith (the so-called carboxy monolith) into a Tris bonded monolith by a post-polymerization functionalization process in the presence of a water soluble carbodiimide, namely N-(3-dimethylaminopropyl)-N´-ethylcarbodiimidehydrochloride. The carbodiimide assisted conversion, allowed the covalent attachment of the carboxyl group of the precursor monolith to the amino group of the Tris ligand via a stable amide linkage. This resulted in the formation of Tris poly(CEA-co-EDMA) monolith, which exhibited the typical retention behavior of hydrophilic interaction stationary phase when analyzing polar and slightly polar neutral or charged compounds. In fact, neutral polar species such as dimethylformamide, formamide and thiourea were retained in the order of increased polarity with acetonitrile rich mobile phase. Also, neutral p-nitrophenyl maltooligosaccharides (PNP-maltooligosaccharides) served as a polar homologous series for gauging the hydrophilicity of the Tris poly(CEA-co-EDMA) monolith, thus forming a versatile testing homologous series for other hydrophilic columns. Other polar anionic species (e.g., hydroxy benzoic acids and nucleotides) and weakly polar anionic compounds (e.g., dansyl amino acids and phenoxy acid herbicides) as well as polar weak bases namely nucleobases and nucleosides were used to probe the hydrophilic characters of the Tris poly(CEA-co-EDMA) monolith. The various polar and weakly polar compounds just mentioned revealed the wide potentiality of the hydrophilic interaction column under investigation.

Simple Detection and Culture of Circulating Tumor Cells from Colorectal Cancer Patients Using Poly(2-Methoxyethyl Acrylate)-Coated Plates.

Here we aimed to establish a simple detection method for detecting circulating tumor cells (CTCs) in the blood sample of colorectal cancer (CRC) patients using poly(2-methoxyethyl acrylate) (PMEA)-coated plates. Adhesion test and spike test using CRC cell lines assured efficacy of PMEA coating. A total of 41 patients with pathological stage II-IV CRC were enrolled between January 2018 and September 2022. Blood samples were concentrated by centrifugation by the OncoQuick tube, and then incubated overnight on PMEA-coated chamber slides. The next day, cell culture and immunocytochemistry with anti-EpCAM antibody were performed. Adhesion tests revealed good attachment of CRCs to PMEA-coated plates. Spike tests indicated that ~75% of CRCs from a 10-mL blood sample were recovered on the slides. By cytological examination, CTCs were identified in 18/41 CRC cases (43.9%). In cell cultures, spheroid-like structures or tumor-cell clusters were found in 18/33 tested cases (54.5%). Overall, CTCs and/or growing circulating tumor cells were found in 23/41 CRC cases (56.0%). History of chemotherapy or radiation was significantly negatively correlated with CTC detection (p = 0.02). In summary, we successfully captured CTCs from CRC patients using the unique biomaterial PMEA. Cultured tumor cells will provide important and timely information regarding the molecular basis of CTCs.

Structure-Property Relationships of Shape Memory, Semicrystalline Polymers Fabricated by In Situ Polymerization and Crosslinking of Octadecyl Acrylate/Polybutadiene Blends.

The current work presents the study of a semicrystalline, shape memory polymer synthesized by simultaneous free radical polymerization and crosslinking in a blend of polybutadiene (PB) and octadecyl acrylate. Blending elastomers and phase change materials provide a modular method for new smart materials, such as shape memory polymers. In this system, grafted, side-chain crystalline poly(octadecyl acrylate) (PODA) fixes a programmed shape in the shape memory cycle, while crosslinked polybutadiene drives shape recovery. This work focuses on improving material parameters important for shape memory (crystallinity, gel fraction, melting temperature) by tuning the processing and formulation parameters (amount of crosslinker and PB weight fraction). The result is a shape memory PB-PODA copolymer that can be fabricated by melt processing and programmed without cooling below ambient temperature. It is found that good shape memory (i.e., high shape fixity and recovery) is obtained at a low PB weight fraction where a percolating PODA crystal network is formed at room temperature. The optimized sample shows excellent shape memory properties (fixity > 99%, recovery = 96%). It is shown that it is possible to mold this material into complex 3D shapes or topography with potential use in anticounterfeiting and antitampering applications.

Poly(carboxyethyl acrylate-co-ethylene glycol dimethacrylate) precursor monolith with bonded (S)-(-)-1-(2-naphthyl) ethylamine ligands for use in chiral and achiral separations by capillary electrochromatography.

In this research report, the previously developed poly(carboxyethyl acrylate-co-ethylene glycol dimethacrylate) precursor monolith (referred to as carboxy monolith) is further exploited in the preparation of a chiral stationary phase for enantiomeric separations. The carboxy monolith precursor was subjected to post polymerization functionalization (PPF) with the chiral selector (S)-(-)-1-(2-naphthyl) ethylamine (NAS) at room temperature in the presence of N, N´-dicyclohexylcarbodiimide (DCC) in chloroform. The DCC, which is an organic soluble carbodiimide, permits the linkage for the amine functionality of the chiral ligand NAS to the carboxy group of the monolithic surface forming a stable amide linkage. The NAS column thus obtained allowed not only enantiomeric separations in the RP mode via its chiral site but also the separation of nonpolar species via its achiral functionality offering both hydrophobic and π-π interactions for aromatic compounds such toluene derivatives and polyaromatic hydrocarbons. The dual interaction sites (e.g., chiral, and achiral) of the NAS present a convenient column for the separations of slightly polar and nonpolar chiral and achiral solutes in the RP mode.

Mussel-inspired poly(hydroxyethyl acrylate-co-itaconic acid)-catechol/hyaluronic acid drug-in-adhesive patches for transdermal delivery of ketoprofen.

This research aimed to create new hydrophilic drug-in-adhesive patches for transdermal drug delivery. Poly(hydroxyethyl acrylate-co-itaconic acid)-catechol (PHI-cat) and hyaluronic acid (HA) were used as main components in the pressure-sensitive adhesive. Citric acid and aluminium hydroxide were exploited as crosslinking agents and ketoprofen was employed as a model delivering compound. The adhesive performance, physicochemical properties, drug-polymer interaction, drug crystallization, drug content, drug permeation through the skin, and coordination polymer network of the patches were investigated. In addition, skin irritation and adhesion potential in human subjects were assessed. Due to the ability of catechol groups to form interaction with the skin tissue, the patches containing PHI-cat and HA offered a considerably greater adhesion ability to human skin compared with the patches without catechol and commercial patches. Furthermore, the patches had good physical and chemical stability. Therefore, these catechol-functionalized patches may be potential transdermal drug delivery systems with excellent adhesive properties for the delivery of a drug through the skin.

Domino Aza-Michael-SNAr-Heteroaromatization Route to C5-Substituted 1-Alkyl-1H-Indole-3-Carboxylic Esters.

A new synthesis of C5-substituted 1-alkyl-1H-indole-3-carboxylic esters is reported. A series of methyl 2-arylacrylate aza-Michael acceptors were prepared with aromatic substitution to activate them towards SNAr reaction. Subsequent reaction with a series of primary amines generated the title compounds. Initially, the sequence was expected to produce indoline products, but oxidative heteroaromatization intervened to generate the indoles. The reaction proceeded under anhydrous conditions in DMF at 23-90 °C using equimolar quantities of the acrylate and the amine with 2 equiv. of K2CO3 to give 61-92% of the indole products. The reaction involves an aza-Michael addition, followed by SNAr ring closure and heteroaromatization. Since the reactions were run under nitrogen, the final oxidation to the indole likely results from reaction with dissolved oxygen in the DMF. Substrates incorporating a 2-arylacrylonitrile proved too reactive to prepare using our protocol. The synthesis of the reaction substrates, their relative reactivities, and mechanistic details of the conversion are discussed.