Copolymerization Of N-butyl Acrylate Research Articles

Design of Clickable Aromatic Donor-Acceptor Pairs for Easy Installation onto Polymers.

New intrinsically unsymmetric aromatic donors (D) and acceptors (A) were designed to simplify the incorporation of a single reactive group. Naphthalene diimide (NDI) was desymmetrized by replacing one of the imide units with two nitro groups to yield 3,6-dinitronaphthalene monoimide (NMI(NO2)2); likewise, 3,6-dimethoxycarbazole (CBZ(OMe)2) was designed as a 3-ring aromatic donor. Different derivatives of naphthalene monoimide (NMI) and carbazole (CBZ) were prepared, and charge-transfer complex formation between them was studied using NMR and UV-visible titrations; the estimated association constants (Ka) were compared with the common pair, NDI, and 1,5-dialkoxy naphthalene (DAN). To rationalize the variation of Ka values, the electrostatic potential maps and the energies of highest-occupied molecular orbital (HOMO) and lowest-unoccupied molecular orbital (LUMO) of different derivatives were computed by using density functional theory. Some of the new D-A pairs outperform the DAN-NDI pair; as expected, the best pair was NMI(NO2)2 and CBZ(OMe)2. The Ka for this pair was 50 M-1, which is slightly higher than that of NDI-DAN but with the advantage that a single reactive handle, like azide, can be easily incorporated and used to click them onto supramolecular motifs or polymers. To illustrate this feature, a low Tg copolymer of n-butyl acrylate and propargyl acrylate (10 mol %) was clicked with the azido-derivatives of the new donors and acceptors; the influence of the charge-transfer interaction on the mechanical properties of blends of these copolymers carrying D and A units was examined using nanoindentation studies. Additionally, the propargyl acrylate copolymers were also coclicked with both D and A units, and their properties were examined as a function of the density of interacting sites. In summary, this study illustrates an alternate design strategy for aromatic donors and acceptors that are easier to synthesize, scale-up, and derivatize; importantly, they can be readily installed onto different motifs for the efficient design of supramolecular materials and polymers.

Structural, morphological and functional properties of films polymer analogues of (co)polyvinylsuccinates

The results of a study of the structural features and associated physicochemical characteristics of films based on copolymers of n-butyl acrylate with N-vinylsuccinamic acid (sodium salt), including those containing bioactive substances (BAS), and their influence on the duration of BAS release depending on chemical structure and composition of the copolymer, film formation conditions, the nature of the introduced BAS, contact medium and release of BAS are presented.

Improved Gas Hydrate Kinetic Inhibition for 5-Methyl-3-vinyl-2-oxazolidinone Copolymers and Synergists.

Kinetic hydrate inhibitors (KHIs) are used to prevent deposits and plugging of oil and gas production flow lines by gas hydrates. The key ingredient in a KHI formulation is a water-soluble amphiphilic polymer. Recently, polymers of a new commercially available 5-ring vinylic monomer 5-methyl-3-vinyl-2-oxazolidinone (VMOX) were investigated as KHIs and shown to perform better than some commercial KHI polymers such as poly(N-vinyl pyrrolidone). This initial study using slow constant cooling (SCC) in rocking cells with a synthetic natural gas has now been expanded to further explore low molecular weight PVMOX homopolymers and VMOX copolymers as well as blends with nonpolymeric synergists. A PVMOX homopolymer with improved KHI performance was found using 3-mercaptoacetic acid as a chain transfer agent in the radical polymerization of VMOX. Among a range of copolymers, VMOX:n-butyl acrylate copolymers in particular gave good KHI performance, better than the PVMOX homopolymer. Among the potential synergists, trialkylamine oxides (alkyl = n-butyl or iso-pentyl) and tetra(n-pentyl)ammonium bromide to 2500 ppm were found to be antagonistic with PVMOX at the test concentrations while some alcohols and glycols were synergetic. The best synergist was 2,4,7,9-tetramethyl-5-decyne-4,7-diol (TMDD). For example, a mixture of 2500 ppm TMDD with 2500 ppm PVMOX (Mw 2400 g/mol) performed significantly better than 5000 ppm PVMOX. Addition of 1250 ppm TMDD to 2500 ppm VMOX:n-butyl acrylate 6:4 copolymer lowered the hydrate onset temperature in SCC tests by a further 3 °C compared to the copolymer alone giving hydrate onset at 4.2 °C.

Investigation on the Effect of Butyl Acrylate (nBA) to Improve the Toughness Properties of Methacrylate-Based Waterproofing Adhesive Material (MMA) for the Steel Bridge Deck

Waterproof adhesion materials (WAL) for steel bridge decks should have comprehensive strong bonding capabilities to steel substrates/pavement layers, water resistance, and persistence to harsh conditions. Methacrylate-based adhesive (MMA), as a typical WAL material for steel bridge decks, lacks sufficient flexibility and diverse compatibility. In this article, flexible, stabile at high temperature, and well-bonded poly (methyl methacrylate)/n-butyl acrylate copolymer [poly(MMA-r-nBA)] coatings were developed with toughening as a breakthrough point. The above properties are obtained by forming an interpenetrating network through interchain van der Waals forces. In addition to the flexibility provided by the long-chain structure of n-butyl acrylate, its unique molecular structure allows it to improve the high-temperature stability and lower the glass transition temperature of MMA. Due to the reduced glass transition temperature, it can also be matched to various pavement layers. Thus, the poly(MMA-r-nBA) composite polymer coatings can be applied to steel bridge decks that require long-term service in various conditions.

Stepwise Gradient Copolymers of n-Butyl Acrylate and Isobornyl Acrylate by Emulsion RAFT Copolymerizations

Gradient copolymers of n-butyl acrylate (nBA) and isobornyl acrylate (IBA) were prepared using reversible addition-fragmentation chain transfer (RAFT) emulsion polymerization. Gradient copolymerizations were conducted using stepwise monomer addition such that the system was monomer-starved. Using the stepwise monomer addition process with a fixed comonomer ratio during the polymerization allows for pre-specified gradient compositions to be obtained. The structural properties of copolymers were confirmed via kinetic investigations and two-dimensional chromatography. 1H nuclear magnetic resonance (NMR) characterization revealed the gradient behavior of the prepared copolymers. The degree of change in monomer composition along the copolymer chain strongly affects the thermal properties of the final polymer product. Thus, gradient copolymers were examined to determine how the strength of the gradient impacts the glass-transition temperature (Tg). Comparisons were also made between the gradient copolymers and their corresponding statistical copolymers and homopolymers. Differential scanning calorimetry analysis of gradient copolymers demonstrated that such copolymers had much broader glass-transition regions compared to homopolymers and statistical copolymers. Furthermore, both the midpoint of the transition (i.e., Tg) and the breadth of the transition were found to be predeterminable through a judicious choice of the comonomer feed composition and the steepness of the comonomer feed in the subsequent monomer additions.

Strong and highly stretchable ionic conductive elastomer based on hydrogen bonding

Rise and development of flexible electronic devices require stretchable semiconductors, but there remains a striking issue of a destruction in conductive network under large deformation. Herein, inspired by the composition of the deep eutectic solvent (DES), we fabricate an ionic conductive elastomer by doping 1-(2-hydroxyethyl)-3-methylimidazolium chloride ([HOEtMIm]Cl) into acid-hydrolyzed copolymer of n-butyl acrylate (nBA) and tert-butyl acrylate (tBA). As a result, our fabricated acid-hydrolyzed P (nAB-co-tBA)/[HOEtMIm]Cl composites possess superior ductility, high tensile strength (1.86 MPa) and good electrical conductivity (2.03 × 10−6 S cm−1), meanwhile, there is no sudden drop in resistance during stretching. [HOEtMIm]Cl disperses uniformly in the matrix as it’s associated with the matrix through hydrogen bonding. As an attempt, we demonstrate its application for touch sensor as well as strain sensor.

The ratio of refractive index and molecular weight of copolymers of n-butyl acrylate and styrene obtained by the method of RAFT-radical polymerization

The kinetic and molecular weight characteristics of the copolymers of n-butyl acrylate and styrene (95: 5 wt.%) obtained by the method of radical polymerization with reversible chain transfer were studied. The dependence of the refractive index on the molecular weight of the copolymers of n-butyl acrylate and styrene is shown.

Amphiphilic Copolymers of Acrylic Acid and n-Butyl Acrylate with the Predetermined Microstructure: Synthesis and Properties

Features of the synthesis of n-butyl acrylate copolymers with acrylic acid in 1,4-dioxane by free radical reversible addition-fragmentation chain transfer (RAFT) polymerization mediated by symmetric trithiocarbonates are considered. It is shown that the living mechanism of polymerization is realized in the studied systems. The chemical nature of the RAFT agent dictates different chain microstructures (random block or random) of the copolymers. The effect of chain microstructure on the properties of the copolymers containing about 90 mol % of acrylic acid units is studied by differential scanning calorimetry, contact angle measurements, turbidimetry, potentiometric titration, and dynamic light scattering. It is demonstrated that all the copolymers in the solid phase have similar properties: a single glass transition temperature close to the glass transition temperature of polyacid and a good water wettability. In dilute aqueous solutions, the properties of the copolymers are different: at the inherent pH, random copolymer macromolecules form large associates, while random block copolymers are dispersed into individual coils or micelles. All the copolymers are weaker polyacids compared with PAA; the random block copolymers are characterized by the compaction of macromolecules at small degrees of ionization. Our studies provide evidence that reversible addition-fragmentation chain transfer polymerization is an efficient tool for the targeted insertion of nonpolar units into a polyelectrolyte chain and it can be used for the fine-tuning of its properties.

The Effect of Solvent Nature on the Adhesive Properties of Binary Styrene–n-Butyl Acrylate Copolymer Films Formed by Casting on Solid Substrates

A methodological approach has been proposed for studying the effect of solvent nature on the adhesive properties of films of binary copolymers with different chain microstructures. The approach is based on a complex analysis of the thermodynamic work of adhesion in polymer–liquid model systems and the results of mechanical tests in combination with quantum-chemical calculations. The approach has been used for the first time for copolymers of styrene and n-butyl acrylate having gradient and random distributions of comonomer units over the chains, with the copolymers being synthesized by radical polymerization with reversible chain transfer. The results obtained have shown that the adhesive properties of the binary copolymer films may be regulated by varying the chemical nature of solvents from which they are formed.

Influence of n-butyl acrylate and maleic anhydride copolymer on the structure and properties of phenolic resin

P(BA-co-MA), the copolymer of n-butyl acrylate (BA) and maleic anhydride (MA) monomers, was synthesized by radical solution polymerization, and its structure was confirmed by 1H NMR and FTIR. Then this prepared P(BA-co-MA) was used to modify the phenolic resin (PF). The chemical structure, mechanical properties and thermal stability of the modified PFs were investigated. The results showed the existence of an esterification reaction between the anhydride groups of P(BA-co-MA) and the phenolic hydroxyl groups of PF during the curing process, which occurred at about 90 °C. In addition, the amount of the phenolic hydroxyl groups in each modified PF was decreased, which obviously increase the thermal stabilities of the modified PFs. The study found that the P(BA-co-MA) was micro spherically distributed in the PF matrix, and P(BA-co-MA) microspheres were tightly bound to the matrix due to the esterification reaction. The results of the research also indicated that all the P(BA-co-MA) modified PFs were all improved in toughness and strength.

The influence of pigment proportions and calendering of coated paperboards on dot gain

Dot gain is called Tone Value Increase (TVI). Low dot gain and rounder dot shape are important properties to obtain a good print. Dot gain is a measure of how much extra weight a given percent dot or tone has gained on the final printed substrate by comparison to the actual dot area on a press plate. Dot gain value depends on many factors. The interactions of paper, ink and press conditions are important determinates for a good print. In addition, the pigment coating process and calendering conditions have a significant effect on the printability of paperboards. Pigment coating formulations including mineral pigments, binders and additives improve the gloss, brightness, opacity and smoothness of the paperboards. As a result, print quality of paperboards increase. A uniform paperboard surface is needed to obtain a high quality surface smoothness after the coating process. High surface smoothness improves the uniformity of the dot shape and size. Pigment coating formulation parameters; pigment selection, binder selection and binder level influence print quality. The aims of this study - pigment selection and ratio - are to determine the effect on dot gain in lithography printing. To this aim, base paperboards were coated using five pigment coating formulations which included different combinations of kaolin, calcium carbonate and titanium dioxide pigment with a styrene\n-butyl acrylate copolymer binder using a bar application. After coating, the samples were air-dried overnight under TAPPI conditions. Then, half of the coated-paperboards were calendered. Tone scales from 1 to 100 % were offset printed using black ink on the uncalendered and calenderedcoated paperboards. Then, from the printed tone scale, the tone area values were measured with the Gretagmacbeth Spectrolino spectrophotometer. These values showed that pigment coating improved the surface optical and physical properties of paperboards. After calendering, the roughness values of coated paperboards decreased. In addition, the obtained dot and line sharpness on calendered-coated paperboards were better than on uncalenderedcoated paperboards. However, the dot gain values of calendered-coated paperboards had fewer dot gains than uncalendered-coated paperboards. It was established that the variation of pigment proportions in the coating formulations had no significant effect on dot gain.

Magnesium hydroxide whisker modified via in situ copolymerization of n-butyl acrylate and maleic anhydride

Magnesium hydroxide (MH) whiskers were modified via in situ polymerization of n-butyl acrylate and maleic anhydride. Sodium dodecyl sulfonate was used as emulsifier. The modifying effect was evaluated by using contact angle and activation index. The thermal stability, functional groups, structure, morphology, phase composition and surface element valence of MH whiskers were characterized by thermogravimetry–differential scanning calorimetry (TG-DSC), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Results reveal that the contact angle and activation index of modified MH whiskers are 105° and 76.5%, the thermal stability shows little change, and the decomposition temperature ranges between 38 and 419 °C. The copolymer of n-butyl acrylate and maleic anhydride absorbed on the surface of MH whiskers leads to the increased diameter and makes the surface of whiskers be rougher. Furthermore, the absorption of element C on the surface of MH whiskers increases, and the diffraction intensity of C 1s spectra increases; thus, the compatibility of whiskers in the organic phase can be improved significantly. Lastly, the surface molecular model of MH whiskers modified via in situ copolymerization of n-butyl acrylate and maleic anhydride is established.

Molecular Origins of Dynamic Coupling between Water and Hydrated Polyacrylate Gels

Energy efficient separation of dilute alcohol–water mixtures is a critical consideration in commercialization of biofuels; pervaporation is an attractive separation technique for this purpose. Knowledge of the mechanism of solvent mobility inside polymeric membranes is of great interest for designing pervaporation-based separation processes. Recently, we employed molecular simulations to study water structure in three polyacrylate gels composed of homopolymers and copolymers of n-butyl acrylate (P(BA)) and 2-hydroxyethyl acrylate (P(HEA)). In this work, water and ethanol dynamics were studied using simulations in two systems: polyacrylate gels swollen to equilibrium and gels with low water content. Solvent dynamics show a concentration-dependent behavior in the gels. For gels swollen to equilibrium, both water and ethanol exhibit the highest mobility in the P(HEA) gel due to the larger degree of swelling of the system, while for gels with a low solvent content, they show the lowest mobility in the P(HEA) ...

Doubly thermo-responsive copolymers in ionic liquid.

We report the behaviour of thermoresponsive block copolymers of n-butyl acrylate and N-alkyl acrylamides in [C2mim][NTf2]. Poly(N-isopropylacrylamide) exhibits an upper critical solution temperature in [C2mim][NTf2] whereas poly(n-butyl acrylate) has a lower critical solution temperature. Consequently, these polymers exhibit double thermo-responsiveness correlated with the macromolecular structure. Moreover, a switching from micellar to reverse micellar structures was induced by a change in temperature. This property enables the development of reversible shuttles between ionic liquids and water.

Changes in compatibility, tack and viscoelastic properties of ethylene n-butyl acrylate (EBA) copolymer–pentaerythritol rosin ester blend by adding microcrystalline wax, Fischer–Tropsch wax and mixture of waxes

Ethylene n-butyl acrylate copolymer (EBA) instead of ethylene vinyl acetate copolymer (EVA) can be used as the base polymer for hot melts. The lower polarity of EBA should affect differently the compatibility with the wax and the tackifier as compared to EVA. In this study the compatibility, tack and viscoelastic properties of EBA copolymer–pentaerythritol rosin ester blended with waxes of different nature (Fischer–Tropsch and microcrystalline) and in different amounts were studied.An increase in compatibility of EBA-copolymer blend with microcrystalline wax was produced leading to increased tack and open time, and reduced viscosity. In contrast, the addition of Fischer–Tropsch wax decreased the compatibility and tack of the EBA-copolymer blend. The addition of a mixture of microcrystalline and Fischer–Tropsch wax caused a better balance in the rheological properties and thermal stability of the EBA-copolymer blends. Finally, an increase in the wax mixture content produced a complete removal of tack caused by dilution of the tackifier in the polymer blend rather than by differences in compatibility.

All-Acrylic Multigraft Copolymers: Effect of Side Chain Molecular Weight and Volume Fraction on Mechanical Behavior

We present the synthesis of poly(n-butyl acrylate)-g-poly(methyl methacrylate) (PnBA-g-PMMA) multigraft copolymers via a grafting-through (macromonomer) approach. The synthesis was performed using two controlled polymerization techniques. The PMMA macromonomer was obtained by high-vacuum anionic polymerization followed by the copolymerization of n-butyl acrylate and PMMA macromonomer using reversible addition–fragmentation chain transfer (RAFT) polymerization to yield the desired all-acrylic multigraft structures. The PnBA-g-PMMA multigraft structures exhibit randomly spaced branch points with various PMMA contents, ranging from 15 to 40 vol %, allowing an investigation into how physical properties vary with differences in the number of branch points and molecular weight of grafted side chains. The determination of molecular weight and polydispersity indices of both the PMMA macromonomer and the graft copolymers was carried out using size exclusion chromatography with triple detection, and the structural ...

Preparation of poly(N-Butyl Acrylate-Co-Glycidyl Methacrylate) and its Application in Enhancement of Epoxy Resin

The epoxy-functionalized copolymers were prepared by copolymerization of n-butyl acrylate (nBA) and glycidyl methacrylate (GMA) in a solution. The structures of the copolymers were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance, and gel-permeation chromatography. The copolymers were added to epoxy resin E44 for modifying the properties of the cured epoxy resin. The results showed that some properties of the cured epoxy resin were apparently improved through the addition of the copolymers. The kinetic studies indicate that the curing process was continuous with average activation energy of 51.13 kJ/mol, which was calculated based on Kissinger and Ozawa models.

Photocrosslinkable Star Polymers via RAFT-Copolymerizations with N-Ethylacrylate-3,4-dimethylmaleimide

This paper describes the Z-RAFT-star copolymerization of n-butyl acrylate (BA) and N-isopropyl acrylamide (NIPAm), respectively, with N-ethylacrylate-3,4-dimethylmaleimide (1.1), a monomer carrying a UV-reactive unit that undergoes photocrosslinking. Addition of 1.1 slows down the polymerization rate both for BA and for NIPAm polymerization. Double star formation due to radical attack to the 3,4-dimethylmaleimide moiety was found in the case of BA. Dead polymer formation, presumably due to aminolysis as side-reaction, was pronounced in the NIPAm system. These two effects broadened the molar mass distributions, but did not impede the formation of functional star polymers. The composition of the copolymers as well as the reactivity ratios for the applied comonomers were determined via NMR spectroscopy (BA-co-1.1 r1.1 = 2.24 rBA = 0.95; NIPAm-co-1.1 r1.1 = 0.96 rNIPAm = 0.05). In both cases, the comonomer is consumed preferably in the beginning of the polymerization, thus forming gradient copolymer stars with the UV-reactive units being located in the outer sphere.

Radical Copolymerization of Maleimide Derivatives with n-butyl Acrylate and Characterization of Polymers

The free radical initiated copolymerization of n-butyl acrylate with N-[4-N′-(aniline amino-carbonyl) phenyl] maleimide (APM), N-[4-N′-{(4-chlorophenyl) amino-carbonyl) phenyl] maleimide (CPM), N-[4-N′-{(4-methylphenyl) amino-carbonyl} phenyl] maleimide (MPM), and N-[4-N′-{(4-methoxy phenyl) amino-carbonyl) phenyl] maleimide (MePM) was carried out in THF at 65°C. The polymers were characterized by solubility test and intrinsic viscosity. The structure of copolymers was analyzed by FT-IR and 1H-NMR spectroscopy. The thermal behavior of copolymers was studied by TGA. The initial decomposition temperature of copolymer samples was in the range of 200°C to 275°C.

PH-Sensitive hydrogels formed by self-assembled amphiphilic triblock copolyelectrolytes

Results are reviewed of a recent extensive investigation of the behavior of self-assembled pH-sensitive triblock copolymers in aqueous solution. The hydrophilic central block was polyacrylic acid and the two hydrophobic end-blocks were statistical copolymers of n-butyl acrylate and acrylic acid containing 50mol% acrylic acid units. The hydrophobicity of the end blocks could be modified by changing the degree of ionization of the acrylic acid units (α). The relationship between the pH and α was determined. Scattering techniques showed that flower-like micelles are formed that upon increasing concentration connect via bridging into larger aggregates and above a critical concentration into a percolating network. The rheology of the system is controlled by the exchange rate of the end-blocks between micelles and can be fine-tuned by varying the pH. The exchange rate increases exponentially with increasing α. As a consequence the system changes from a quasi-permanent hydrogel at pH<4.5 to a free flowing liquid at pH>5.5. The effect of the ionic strength on the structure and the rheology was found to be important only above 0.5M.