Methacrylate Copolymers Research Articles

SYNTHESIS AND STUDY OF THE PROPERTIES OF EPOXYCYCLOCARBONATES BASED ON ACRYLATE-VINYL COPOLYMERS

A method of synthesis of acrylate-vinyl copolymers based on glycidyl methacrylate and styrene at different molar ratios and epoxy cyclocarbonates based on them was developed. Synthesis of styrene-glycidyl methacrylate (СP GMA/St) copolymers was carried out by the method of thermally initiated radical polymerization in steel reactors in the presence of 1% azo-bis-isobutyronitrile initiator at a temperature of 65 °C for 10 hours. The number of epoxy groups in the synthesized СP GMA/St, determined by the potentiometric titration method, naturally decreases with a decrease in the molar ratio of GMA/styrene. The synthesis of СP GMA/St epoxycyclocarbonates was carried out in a high-pressure autoclave by passing CO2 through the reaction mixture of a solution of KP in toluene with a catalyst (tetrabutylammonium bromide 5%) with stirring at a temperature of 110–120 °C, a pressure of (4-5) atm. The structure of СP and ECC was confirmed by IR spectroscopy. No bands of double bonds are observed in the IR spectra of СP GMA/St, there are vibration bands characteristic of oligostyrene and vibration bands of C=O, C–O–C and epoxy groups. During the formation of ECC, new vibration bands of cyclocarbonate groups with a maximum of 1802 cm-1 appear, changes are observed in the absorption region of C–O–C groups (1100–1300) cm-1, and the vibration bands of epoxy groups with a maximum of 843 cm-1 decrease. The study of relaxation transitions in acrylate-vinyl copolymers GMA/St and epoxy cyclocarbonates based on them using the DSC method showed that all samples are amorphous single-phase polymers. After changing the background, the excessive enthalpy observed during the first heating disappears, and the glass transition temperature shifts towards higher temperatures, which indicates the formation of a denser and thermodynamically balanced structure. The thermostability of the synthesized GMA/St copolymers and epoxy cyclocarbons was investigated by the method of thermogravimetry. It was established that all the obtained substances have one stage of weight loss and are heat resistant, since weight loss begins at a temperature above 240 °C. In the future, the obtained epoxycyclocarbonates will be used for the synthesis of polyurethanes by the non-isocyanate method.

Synthesis and characterization of functional thermoresponsive photoactive copolymers and study of their thermal and photoluminescence properties

ABSTRACT Poly(N-isopropyl acrylamide-co-disperse yellow 7 methacrylate) (PNIPAM) copolymers were synthesized by radical polymerization of N-isopropyl acrylamide with disperse yellow 7 methacrylate using 2,2/-Azo-bis-isobutyronitrile (AIBN) as an initiator. N-isopropyl acrylamide is a thermoresponsive monomer, and disperse yellow 7 methacrylate is a photoactive monomer. The synthesized photoactive and thermoresponsive copolymers were characterized by FTIR, NMR, and UV-Vis spectrophotometer with a temperature variation. A proton NMR signal at 8.16 ppm is observed for aromatic protons surrounded by an azo (-N=N-) group. The peak that appeared at 4.0 ppm is due to the CH-CONH group. The amide group proton of CONH appeared at 8.16 ppm. The molecular weights of homopolymers (like PNIPAM and PDY7MA) and their copolymers (PNIPDY) were observed to be 104 and 103 Da, respectively. The optical band gaps for synthesized copolymers, PNIPDY-1B, PNIPDY-2B, and PNIPDY-3B, are 2.98 eV, 2.95 eV, and 2.91 eV, respectively. The multiple emission spectra were observed at 407 nm, 428 nm, and 460 nm for the excitation energy of 365 nm due to the n-π* and π-π* transitions of the azobenzene chromophore. Thermal properties were also studied using TGA analysis. Stimuli-responsive polymers are widely used in optoelectronics and photonics, such as optical switching, optical information storage devices, liquid crystal display technology, and diffractive optical elements.

Tough, Hydrophobic, Pressure-Resistant, and Self-Cleaning Underwater Engineering Materials Based on Copolymerization of Butadiene and Trifluoroethyl Methacrylate

Tough, Hydrophobic, Pressure-Resistant, and Self-Cleaning Underwater Engineering Materials Based on Copolymerization of Butadiene and Trifluoroethyl Methacrylate

Cationic β‐Scission of C−H and C−C Bonds for Selective Dimerization and Subsequent Sulfur‐Free RAFT Polymerization of α‐Methylstyrene and Isobutylene

AbstractA series of exo‐olefin compounds ((CH3)2C(PhY)−CH2C(=CH2)PhY) were prepared by selective cationic dimerization of α‐methylstyrene (αMS) derivatives (CH2=C(CH3)PhY) with p‐toluenesulfonic acid (TsOH) via β‐C−H scission. They were subsequently used as reversible chain transfer agents for sulfur‐free cationic RAFT polymerization of αMS via β‐C−C scission in the presence of Lewis acid catalysts such as SnCl4. In particular, exo‐olefin compounds with electron‐donating substituents, such as a 4‐MeO group (Y) on the aromatic ring, worked as efficient cationic RAFT agents for αMS to produce poly(αMS) with controlled molecular weights and exo‐olefin terminals. Other exo‐olefin compounds (R−CH2C(=CH2)(4‐MeOPh)) with various R groups were prepared by different methods to examine the effects of R groups on the cationic RAFT polymerization. A sulfur‐free cationic RAFT polymerization also proceeded for isobutylene (IB) with the exo‐olefin αMS dimer ((CH3)2C(Ph)−CH2C(=CH2)Ph). Furthermore, telechelic poly(IB) with exo‐olefins at both terminals was obtained with a bifunctional RAFT agent containing two exo‐olefins. Finally, block copolymers of αMS and methyl methacrylate (MMA) were prepared via mechanistic transformation from cationic to radical RAFT polymerization using exo‐olefin terminals containing 4‐MeOPh groups as common sulfur‐free RAFT groups for both cationic and radical polymerizations.

Cationic β-Scission of C-H and C--C Bonds for Selective Dimerization and Subsequent Sulfur-Free RAFT Polymerization of α-Methylstyrene and Isobutylene.

A series of exo-olefin compounds ((CH3)2C(PhY)-CH2C(=CH2)PhY) were prepared by selective cationic dimerization of α-methylstyrene (αMS) derivatives (CH2=C(CH3)PhY) with p-toluenesulfonic acid (TsOH) via β-C-H scision. They were subsequently used as reversible chain transfer agents for sulfur-free cationic RAFT polymerization of αMS via β-C-C scission in the presence of Lewis acid catalysts such as SnCl4. In particular, exo-olefin compounds with electron-donating substituents, such as a 4-MeO group (Y) on the aromatic ring, worked as efficient cationic RAFT agents for αMS to produce poly(αMS) with controlled molecular weights and exo-olefin terminals. Other exo-olefin compounds (R-CH2C(=CH2)(4-MeOPh)) with various R groups were prepared by different methods to examine the effects of R groups on the cationic RAFT polymerization. A sulfur-free cationic RAFT polymerization also proceeded for isobutylene (IB) with the exo-olefin αMS dimer ((CH3)2C(Ph)-CH2C(=CH2)Ph). Furthermore, telechelic poly(IB) with exo-olefins at both terminals was obtained with a bifunctional RAFT agent containing two exo-olefins. Finally, block copolymers of αMS and MMA were prepared via mechanistic transformation from cationic to radical RAFT polymerization using exo-olefin terminals containing 4-MeOPh groups as common sulfur-free RAFT groups for both cationic and radical polymerizations.

Residue-free and nondestructive separation of transparent adhesive thin films using the interfacial coating of thermo-responsive nanocapsules

The effective separation of flexible optoelectronic panels bonded with transparent adhesive films is an innovative technology that enables the reuse of expensive devices, reducing manufacturing costs in multilayered flexible displays. Herein, we present an effective, facile strategy for heat-triggered detachment of adhesive thin films with high optical transparency by interfacial coating with thermo-responsive nanocapsules. These temperature-sensitive nanocapsules, comprising reactive benzenesulfonyl hydrazide cores and polyacrylonitrile-poly(methyl methacrylate) copolymer shells, were simply prepared through a one-pot synthesis using surfactant-free emulsion polymerization. The synthesized nanocapsules were mixed with UV-curable resins and applied as a thin interfacial layer on the substrate through blade coating and UV curing, producing a transparent, uniform nanocapsule layer of 10 μm with extensive coverage. A transparent double-layered adhesive film was achieved by stacking optically clear adhesive film on the interfacial nanocapsule layer. Compared with pure transparent adhesive film, this double-layered adhesive film containing interfacial nanocapsule layer yields a remarkable optical transparency of 99.1 % and high initial adhesion strength of 98.2 %. Furthermore, a short-time heat treatment at 100 °C produces numerous gas microbubbles in the interfacial region between the substrate and optical thin film, facilitating their clean and spontaneous detachment with an outstanding desorption efficiency of 78.7 %. Our separation approach will be helpful for providing a promising way to dismantle polymer thin films without surface damage in wide industries from semiconductor packaging to flexible devices.

Robust and adhesive double-solvent phase change hydrogel with reversible transparency and shape memory for thermal management and information encryption

The excellent energy storage capacity of solid–liquid phase change materials has attracted considerable attention, but the vulnerability to leakage limits their applications. Therefore, the development of composite phase change materials has become a hot research topic in recent years. Therefore, a double-solvent (DS) phase change hydrogel (PCH) prepared by random copolymerization of acrylic acid (AA) and hydroxyethyl methacrylate (HEMA) with water and polyethylene glycol (PEG) as solvents was proposed. The phase transition enthalpies of melting and crystallization of the gel reached 116.2 J·g−1 and 113.5 J·g−1, respectively. PCH exhibits good morphological stability while storing thermal energy, which can effectively encapsulate phase change materials without leakage at high temperatures and be recyclable. PEG is used as both solvent and phase change part and the prepared gel reveals a high phase change material loading rate (76.2%), high breaking stress (4.7 MPa) and excellent compression resistance (1.2 MPa), superior to existing counterparts. The presence of a small amount of water in the system endows the gel with certain flexibility. Moreover, due to the solid–liquid phase transition behavior of PEG during temperature changes, PCHs possesses reversible adhesion and transparency, as well as shape memory properties. In addition, its low thermal conductivity and high energy storage efficiency make it perform well in the field of infrared stealth.

Super-tough polylactic acid (PLA)/poly(butylene succinate) (PBS) materials prepared through reactive blending with epoxy-functionalized PMMA-GMA copolymer

High-performance biosourced polylactic acid (PLA)/poly(butylene succinate) (PBS) blends with small amounts of compatibilizer, epoxy-functionalized methyl methacrylate-co-glycidyl methacrylate copolymer (PMMA-GMA), were fabricated by melt compounding. The properties of the modified PLA/PMMA-GMA, PBS/PMMA-GMA, and PLS(PLA/PBS)/PMMA-GMA blends were investigated systematically. DSC combined with X-ray diffraction revealed a low-order semi-crystalline structure for all samples. SEM and DMA showed that the compatibility between PLA and PBS was improved after addition of PMMA-GMA. Rheological behavior of blends showed that the addition of PMMA-GMA resulted in a significant improvement in the viscoelasticity. FT-IR spectra confirmed that the interfacial compatibilization between PLA and PBS phases was improved due to the reaction of epoxy groups with terminal groups of PLA and PBS. Finally, the toughness and notched impact strength of the PLA materials were increased significantly. The elongation at break and notched impact strength of PLS/PMMA-GMA was about 55.7 and 6.2 times than neat PLA after incorporation of 7 wt% PMMA-GMA, respectively.

Evaluation of block copolymer and homopolymer of stearyl methacrylate as multifunctional additives for lubricating oil

Evaluation of block copolymer and homopolymer of stearyl methacrylate as multifunctional additives for lubricating oil

Effect of alkyl methacrylate/glycidyl methacrylate copolymer backbone structure on mechanical properties of hydroxyurethane-crosslinked networks

The effect of cyclic carbonate functionalized polymer backbones on mechanical and rheological properties of hybrid thermoset resins with hydroxyurethane linkages via vegetable-oil derived diamine were investigated. Atom transfer radical polymerization (ATRP) of binary methyl, ethyl, butyl methacrylate (MMA, EMA, BMA) mixtures with glycidyl methacrylate (GMA) with various GMA initial molar fractions (fGMA = 0.1–0.9) were performed at 70 °C to create precursor backbones with modulated glass transition temperature (Tg). The copolymer compositions were essentially statistical as demonstrated by estimated reactivity ratios. MMA/GMA reactivity ratios were rMMA = 0.80 ± 0.09 and rGMA = 1.35 ± 0.09, which agreed with earlier studies while previously unreported EMA/GMA reactivity ratios were rGMA = 1.10 ± 0.09 and rEMA = 0.31 ± 0.09 and BMA/GMA reactivity ratios were rBMA = 0.67 ± 0.09 and rGMA = 1.45 ± 0.09. The synthesized copolymers were then carbonated, converting the pendent epoxy functional groups to cyclic carbonates. The carbonated copolymers were reacted with the vegetable oil-derived diamine Priamine 1074 to form relatively rigid side chains via hydroxyurethane linkages to the backbone. Degree of flexibility of backbones and cyclic carbonate functionality were manipulated to synthesize crosslinked networks with Young's moduli ranging from 395 MPa to 1250 MPa.

A light-responsive wound dressing hydrogel: Gelatin based self-healing interpenetrated network with metal-ligand interaction by ferric citrate.

Interpenetrated network (IPN) hydrogels with desired mechanical properties were prepared based on gelatin. A copolymer of dimethyl aminoethyl methacrylate (DMAEMA) with 2-Acrylamido-2-methylpropane sulfonic acid (AMPS) in gelatin was chemically cross-linked with methylene bis acrylamide (MBA) to form a semi-IPN hydrogel. Also, IPN hydrogel is fabricated from the AMPS-co-DMAEMA and gelatin in the presence of ferric ions with both chemical and physical cross-linkers. According to the compression test, the metal-ligand interaction has a remarkable impact on the mechanical strength of hydrogel. Ferric ions caused a decrease in the pores size confirmed by the SEM images of hydrogels, resulting in preserving its mechanical stability during the swelling test due to a more robust structure of hydrogel. Ferric to ferrous ions reduction is observed under visible light irradiation, which results in a light-sensitive hydrogel with a higher rate of biodegradation compared to semi-IPN hydrogels. MTT assay results implied that the synthesized hydrogels are non-toxic for the L-929 cell line. Also, for more detailed investigations, histological studies are conducted as in vivo tests. With regards to the improvements of mechanical properties harnessed in IPN hydrogels by ferric ions along with the extraordinary self-healing capability, IPNs would be considered an appropriate option for tissue engineering.

Dynamic anticounterfeiting polymeric inks for multipurpose time-dependent encryption with a high level of security

Development of dynamic anticounterfeiting inks with time-dependent photochromism and photoluminescence characteristics has become highly interesting in advanced encryption systems. These inks are applicable in different fields, such as tracking UV rays and gas leakage and also quality monitoring. In this study, semi-continuous copolymerization of butyl acrylate and methyl methacrylate in the heterogeneous miniemulsion medium was used to synthesize colloidal nanoparticles with different flexibilities and polarities. Then, hydroxyl-functional spiropyran (SPOH) was physically incorporated into the nanoparticles to prepare photochromic and photoluminescent inks. The nanoparticles showed low light reflectance due to their small size, which makes them applicable in photoresponsive and sensing applications. In addition, the nanoparticles exhibited different glass transition temperature (Tg) that affects their photoresponsivity. Microscopic analysis revealed that all the latex samples have spherical nanoparticles with a mean size of about 70 nm and a low polydispersity index. UV–vis absorption and fluorescence emission spectra, isomerization kinetics, and photofatigue resistance of the photochromic latex nanoparticles were studied, which depend on chain polarity and flexibility of the latex nanoparticles. The optical properties of the photochromic materials are closely related to the structure and composition of the latex samples. Time-dependent features of the inks originate from their spiropyran molecules which gradually turns into the merocyanine form upon visible light induction. Photochromic inks with advanced encryption and dynamic characteristics were developed from the SPOH-doped colloidal latex nanoparticles. Different polarities and Tg of the inks result in their different dynamic chromism, which show their high level of information encryption technology. By virtue of these unique time-dependent properties, the encryption capabilities of these inks are significantly improved. These inks achieved unprecedented advances in the field of information security and encryption because of their innovative features.

A novel CO2 based UV-induced peelable adhesive for wafer dicing

Poly (propylene carbonate) diol with double-bonds on the side chains (PPCAGE) was synthesized form CO2, propylene oxide (PO), polyether diol (PPG) and allyl glycidyl ether (AGE). Then, three kinds of CO2 based polyurethane oligomers (PPCAGE-PU) (PPCAGE-PUA, PPCAGE-PUB and PPCAGE-IPDI, respectively) with different contents of double bond were prepared through the reaction of PPCAGE, isophorone diisocyanate (IPDI) and hydroxyethyl acrylate (HEA). The content of -NCO was adjusted by varying the ratio of -NCO terminated prepolymer and HEA. Acrylate copolymer with side double bonds and hydroxyl groups (GMA-PSA) was synthesized by the ring-opening reaction of glycidyl methacrylate (GMA) and acrylate copolymer (PSA) containing -COOH and -OH. CO2 based UV-induced peelable adhesive was prepared by mixing PPCAGE-PU, GMA-PSA, active diluent and photoinitiator. The structure of PPCAGE was confirmed by Fourier transform infrared (FT-IR) and nuclear magnetic resonance (1H NMR). The reaction of PPCAGE-PUB and GMA-PSA was monitored by FT-IR, companied by the titration of -NCO and epoxide. The molecular weight of PSA and GMA-PSA was determined by gel permeation chromatography (GPC). The surface morphology of the adhesive was observed by scanning electron microscopy (SEM). The viscoelasticity of adhesive was measured by real-time rheology. The 180° peel strength, micro-surface morphology, gel content, unsaturation conversion and glass transition temperature of UV-induced peelable adhesive were characterized. The results showed that the peel strength of adhesive was 17.82 N/25 mm before UV curing. After UV curing, the surface morphology changed from smooth to rough, the peel strength decreased to 0.08 N/25 mm and the modulus of the PSA increased due to the cross-linking. DSC results showed that the glass transition temperature increased after UV curing.

A schematic representation of pyrolysis and oxidative decomposition paths of more environmentally friendly, high chemical and solvent resistant poly(geranyl methacrylate)-co-poly(benzyl methacrylate) copolymers studied by the TG/FTIR/QMS

A schematic representation of pyrolysis and oxidative decomposition paths of poly(geranyl methacrylate)-co-poly(benzyl methacrylate) copolymers (GM-co-BM) using a simultaneous TG/FTIR/QMS analysis has been evaluated, for the first time. The tested polymers are more environmentally friendly, high chemical and solvent resistant materials with a glass transition temperature below 47 °C. Their pyrolysis took place in one main stage visible from 220 °C± 3–245 °C± 2–440–500 °C, depending on their composition. The pyrolysis was connected with the emission of benzyl methacrylate, methacrylic acid, myrcene, geraniol, citral, H2O and some low molecular mass fragments. In turn, the oxidative decomposition of the tested copolymers run in two main stages. The first stage from 205 °C± 5–230 °C± 4–340–380 °C was visible. This was connected with the emission of benzyl methacrylate, myrcene, citral, low molecular mass alkenes and ketones, CO2, H2O and CO. The second stage occurred from 340° to 380–520 °C. Mainly, the formation of CO2, H2O and CO and some low molecular mass fragments was observed. The type of the formed volatiles indicated that the pyrolysis and oxidative decomposition were initiated by a radical mechanism. The symmetric cleavage of the C-C and C-O bonds in the main and side macromolecular chains of the studied GM-co-BM materials (inert conditions) and additional chemical reactions of the formed fragments with oxygen and/or residues (oxidative conditions) were confirmed.

Preparation of acidity-sensitive N-isopropylacrylamide and methacrylic acid copolymer monolithic column for the pipette tip solid phase extraction of phenols

An acidity-sensitive poly(N-isopropylacrylamide-methyl acrylic acid-co-divinyl- benzene) monolith was prepared in situ in a pipette tip for solid phase extraction of phenol, m-cresol, o-nitrophenol, 2,4-dichlorophenol and p-tert-butylphenol. The monolith was characterized by FT-IR, BET (surface area = 266.56 m2/g) and thermogravimetric analysis (thermally stable up to 350 °C). The introduction of methyl acrylic acid enhanced the stability in the strong alkaline condition. The adsorption experiments and density function theory calculations indicated NIPAM was the main adsorption sites and the adsorption mechanism of phenol on the monolith was hydrophobic interaction, H-bond interaction, C − H···π interaction of isopropyl group of NIPAM with the phenyl group of phenols. Based on these features and under the optimal extraction conditions, a pipette tip solid phase extraction coupled to high-performance liquid chromatography with ultraviolet detection method was developed for the determination of 5 phenols in the diffusion of polycarbonate cups. Due to the usage of 0.1 M NaOH as the eluent, the method presented selectivity for phenols based on the acidity-sensitive of the monolith. Wide linear range (0.6–200 µg/L), low detection limits (0.2–0.3 µg/L), good reproducibility (%RSD less than 9.8%) and satisfactory recoveries (86.3–114.1%) were obtained. The proposed method was suitable for quantitative analysis of phenollic in water samples.

Acrylonitrile–butadiene–styrene (ABS) salami structure inspired PLLA composites with excellent stiffness-toughness balance

The stiffness-toughness balance of polymeric materials poses great challenges. Acrylonitrile–butadiene–styrene terpolymer (ABS) exhibits excellent mechanical and processing properties due to its unique “salami” morphologies. Inspired by this, we proposed a three-step reactive processing strategy to design high performance polylactide (PLLA) composites with the similar “sub-inclusion” microstructure. The reactive micro-crosslinked elastomer with bifunctional groups (RMCE) was first prepared by the blending of γ-aminopropyl-triethoxysilane (KH550) with the random copolymer of ethylene-acrylic ester-glycidyl methacrylate (EGMA). The following mixing of the minor PLLA with the RMCE leads to the double-ended fixing of polylactide molecular chain in the RMCE. The PLLA included reactive micro-crosslinked elastomers (IRCE) were then used to toughen PLLA, inducing the formation of PLLA alloys with the unique sub-inclusion morphology. Surprisingly, magnificent stiffness-toughness balance can be achieved for the obtained PLLA composites. This work opens up a new strategy for preparing high-performance polyester composites with excellent stiffness-toughness balance.

Mean Free Path of Electrons in Organic Photoresists for Extreme Ultraviolet Lithography in the Kinetic Energy Range 20-450 eV.

The blur caused by the nonzero mean free path of electrons in photoresists exposed by extreme ultraviolet lithography has detrimental consequences on patterning resolution, but its effect is difficult to quantify experimentally. So far, most mean free path calculations use the dielectric formalism, which is an approximation valid in the optical limit and fails at low kinetic energy. In this work, we used a modified substrate-overlayer technique that exploited the attenuation of the Si 2p core level originating specifically from the native silicon dioxide to evaluate the attenuation of electrons traveling through 2 and 4 nm of photoresist overlayers to provide a close estimation of the inelastic mean free path relevant for photoresist lithography patterning and for electron microscopy. The photoemission spectra were collected in the proximity of the Si 2p edge (binding energy ∼101 eV) using synchrotron light of energy ℏω ranging between 120 and 550 eV. The photoresist films were prototypical chemically amplified resists based on organic copolymer of poly hydroxystyrene and tertbutyl methacrylate with and without triphenyl sulfonium perfluoro-1-butanesufonate photoacid generator and trioctylamine quencher. The inelastic mean free path of electrons, in the range that is relevant for photoresist exposure in extreme ultraviolet lithography (20-92 eV), was found to be between 1 and 2 nm. At higher kinetic energy, the mean free path increased, consistently with the well-known behavior. The presence of the photoacid generator and quencher did not change the mean free path, within experimental error. Our results are discussed and compared with the existing literature on organic molecules measured via dielectric formalism and electron transmission experiments.

Promising Gene Delivery Properties of Polycations Based on 2-(N,N-dimethylamino)ethyl Methacrylate and Polyethylene Glycol Monomethyl Ether Methacrylate Copolymers.

Cationic copolymers based on 2-(N,N-dimethylamino)ethyl methacrylate and polyethylene glycol monomethyl ether (pDMAEMA-co-PEO) with different molecular weights have been synthesized. Their physicochemical properties were studied by NMR spectroscopy, sedimentation, and potentiometric titration. According to the data of potentiometric titration for the synthesized pegylated cationic copolymers, the apparent dissociation constants were determined in the pH range from 4.5 to 8.5. The physicochemical properties of interpolyelectrolyte complexes of these polycations with circular DNA (IPEC DNA) were also studied by dynamic light scattering, electrophoretic mobility, and TEM methods. It has been established that the diameter and electrokinetic potential (ζ-potential) of interpolyelectrolyte complexes can be varied over a wide range (from 200 nm to 1.5 μm and from -25 mV to +30 mV) by changing the ratio of oppositely charged ionizable groups in pegylated cationic copolymers and DNA, as well as by regulating medium pH. The resistance of the IPEC DNA/polycation complex to the action of nucleases was studied by electrophoresis in agarose gel; the cytotoxic effect of the polymers in vitro, and the efficiency of penetration (transfection) of IPEC DNA with PDMAEMA-co-PEO-polycations into eukaryotic cells of a cell line derived from human embryonic kidneys HEK 293 in vitro.

Complementary Supramolecular Functionalization Enhances Antifouling Surfaces: A Ureidopyrimidinone-Functionalized Phosphorylcholine Polymer.

Fibrosis of implants remains a significant challenge in the use of biomedical devices and tissue engineering materials. Antifouling coatings, including synthetic zwitterionic coatings, have been developed to prevent fouling and cell adhesion to several implantable biomaterials. While many of these coatings need covalent attachment, a conceptually simpler approach is to use a spontaneous self-assembly event to anchor the coating to a surface. This could simplify material processing through highly specific molecular recognition. Herein, we investigate the ability to utilize directional supramolecular interactions to anchor an antifouling coating to a polymer surface containing a complementary supramolecular unit. A library of controlled copolymerization of ureidopyrimidinone methacrylate (UPyMA) and 2-methacryloyloxyethyl phosphorylcholine (MPC) was prepared and their UPy composition was assessed. The MPC-UPy copolymers were characterized by 1H NMR, Fourier transform infrared (FTIR), and gel permeation chromatography (GPC) and found to exhibit similar mol % of UPy as compared to feed ratios and low dispersities. The copolymers were then coated on an UPy elastomer and the surfaces were assessed for hydrophilicity, protein absorption, and cell adhesion. By challenging the coatings, we found that the antifouling properties of the MPC-UPy copolymers with more UPy mol % lasted longer than the MPC homopolymer or low UPy mol % copolymers. As a result, the bioantifouling nature could be tuned to exhibit spatio-temporal control, namely, the longevity of a coating increased with UPy composition. In addition, these coatings showed nontoxicity and biocompatibility, indicating their potential use in biomaterials as antifouling coatings. Surface modification employing supramolecular interactions provided an approach that merges the simplicity and scalability of nonspecific coating methodology with the specific anchoring capacity found when using conventional covalent grafting with longevity that could be engineered by the supramolecular composition itself.

Harnessing Bile for Drug Absorption through Rational Excipient Selection.

Bile solubilization and apparent solubility at resorption sites critically affect the bioavailability of orally administered and poorly water-soluble drugs. Therefore, identification of drug-bile interaction may critically determine the overall formulation success. For the case of the drug candidate naporafenib, drug in solution at phase separation onset significantly improved with polyethylene glycol-40 hydrogenated castor oil (RH40) and amino methacrylate copolymer (Eudragit E) but not with hydroxypropyl cellulose (HPC) in both phosphate-buffered saline (PBS) and PBS supplemented with bile components. Naporafenib interacted with bile as determined by 1H and 2D 1H-1H nuclear magnetic resonance spectroscopy and so did Eudragit E and RH40 but not HPC. Flux across artificial membranes was reduced in the presence of Eudragit E. RH40 reduced the naporafenib supersaturation duration. HPC on the other side stabilized naporafenib's supersaturation and did not substantially impact flux. These insights on bile interaction correlated with pharmacokinetics (PK) in beagle dogs. HPC preserved naporafenib bile solubilization in contrast to Eudragit E and RH40, resulting in favorable PK.