Acrylate Mixture Research Articles

Photo-Crosslinked Polyurethane-Containing Gel Polymer Electrolytes via Free-Radical Polymerization Method.

Using a novel technique, crosslinked gel polymer electrolytes (GPEs) designed for lithium-ion battery applications have been created. To form the photo crosslink via free-radical polymerization, a mixture of polyurethane acrylate (PUA), polyurethane methacrylate (PUMA), vinyl phosphonic acid (VPA), and bis[2-(methacryloyloxy)ethyl] phosphate (BMEP) was exposed to ultraviolet (UV) radiation during the fabrication process. The unique crosslinked configuration of the membrane increased its stability and made it suitable for use with liquid electrolytes. The resulting GPE has a much higher ionic conductivity (1.83 × 10-3 S cm-1) than the commercially available Celgrad2500 separator. A crosslinked structure formed by the hydrophilic properties of the PUA-PUMA blend and the higher phosphate content from BMEP reduced the leakage of the electrolyte solution while at the same time providing a greater capacity for liquid retention, significantly improving the mechanical and thermal stability of the membrane. GPP2 shows electrochemical stability up to 3.78 V. The coin cell that was assembled with a LiFePO4 cathode had remarkable cycling characteristics and generated a high reversible capacity of 149 mA h g-1 at 0.1 C. It also managed to maintain a consistent Coulombic efficiency of almost 100%. Furthermore, 91.5% of the original discharge capacity was maintained. However, the improved ionic conductivity, superior electrochemical performance, and high safety of GPEs hold great promise for the development of flexible energy storage systems in the future.

Surface morphology of core/shell particles and its determining factors

Submicron-sized core/shell particles were prepared by polymerizing a mixture of methyl methacrylate and butyl acrylate in the presence of seeds of monodisperse polystyrene or its copolymer with methyl methacrylate. The influence of core/shell particle preparation conditions (method of shell formation, core composition, reaction temperature, introduction of surfactants, method of introducing monomers) on kinetics of the process, shape and surface morphology of the resulting particles is revealed. Depending on the abovementioned parameters, particles of various morphologies can be obtained, including both ones with a smooth surface layer and with a heterogeneous “golf ball-like” structure, while the presence of dents, as well as their size and the number can also be controlled by the synthesis conditions. The result of polymerization, that is, the morphology of core/shell particles and the formation of secondary particles, is established to be determined primarily by thermodynamic factors that take into account the distribution of shell-forming monomers in an equilibrium state.

Viscosity Studies of Binary Liquid Mixture of Methyl Acrylate and Benzene and Substituted Halo Benzenes at 313.15k

Studied the binary liquid mixtures of Methyl Acrylate with Benzene (B), and Substituted Halo Benzene molecules like Chloro Benzene (CB) and Bromo Benzene (BB) at 313.15K. Initially, the density and viscosities of the mixtures are measured and this data is utilized to calculate excess properties like excess molar volume (VE), excess viscosity (ηE), and excess Gibbs free energy (ΔG*E). These excess parameter values are fitted in the Redlich–Kister Polynomial equation and the intermolecular interaction is discussed.

Cyclic and Linear Tetrablock Copolymers Synthesized at Speed and Scale by Lewis Pair Polymerization of a One-Pot (Meth)acrylic Mixture and Characterized at Multiple Levels.

Cyclic block copolymers (cBCP) are fundamentally intriguing materials, but their synthetic challenges that demand precision in controlling both the monomer sequence and polymer topology limit access to AB and ABC block architectures. Here, we show that cyclic ABAB tetra-BCPs (cABAB) and their linear counterpart (lABAB) can be readily obtained at a speed and scale from one-pot (meth)acrylic monomer mixtures, through coupling the Lewis pair polymerization's unique compounded-sequence control with its precision in topology control. This approach achieves fast (<15 min) and quantitative (>99%) conversion to tetra-BCPs of predesignated linear or cyclic topology at scale (40 g) in a one-pot procedure, precluding the needs for repeated chain extensions, stoichiometric addition steps, dilute conditions, and postsynthetic modifications, and/or postsynthetic ring-closure steps. The resulting lABAB and cABAB have essentially identical molecular weights (Mn = 165-168 kg mol-1) and block degrees/symmetry, allowing for direct behavioral comparisons in solution (hydrodynamic volume, intrinsic viscosity, elution time, and refractive indices), bulk (thermal transitions), and film (thermomechanical and rheometric properties and X-ray scattering patterns) states. To further the morphological characterizations, allylic side-chain functionality is exploited via the thiol-ene click chemistry to install crystalline octadecane side chains and promote phase separation between the A and B blocks, allowing visualization of microdomain formation.

Clopidogrel-loaded vascular grafts prepared using digital light processing 3D printing

The leading cause of death worldwide and a significant factor in decreased quality of life are the cardiovascular diseases. Endovascular operations like angioplasty, stent placement, or atherectomy are often used in vascular surgery to either dilate a narrowed blood artery or remove a blockage. As an alternative, a vascular transplant may be utilised to replace or bypass a dysfunctional or blocked blood vessel. Despite the advancements in endovascular surgery and its popularisation over the past few decades, vascular bypass grafting remains prevalent and is considered the best option for patients in need of long-term revascularisation treatments. Consequently, the demand for synthetic vascular grafts composed of biocompatible materials persists. To address this need, biodegradable clopidogrel (CLOP)-loaded vascular grafts have been fabricated using the digital light processing (DLP) 3D printing technique. A mixture of polylactic acid-polyurethane acrylate (PLA-PUA), low molecular weight polycaprolactone (L-PCL), and CLOP was used to achieve the required mechanical and biological properties for vascular grafts. The 3D printing technology provides precise detail in terms of shape and size, which lead to the fabrication of customised vascular grafts. The fabricated vascular grafts were fully characterised using different techniques, and finally, the drug release was evaluated. Results suggested that the performed 3D-printed small-diameter vascular grafts containing the highest CLOP cargo (20% w/w) were able to provide a sustained drug release for up to 27 days. Furthermore, all the CLOP-loaded 3D-printed materials resulted in a substantial reduction of the platelet deposition across their surface compared to the blank materials containing no drug. Haemolysis percentage for all the 3D-printed samples was lower than 5%. Moreover, 3D-printed materials were able to provide a supportive environment for cellular attachment, viability, and growth. A substantial increase in cell growth was detected between the blank and drug-loaded grafts.Graphical

Rapid surface texturing to achieve robust superhydrophobicity, controllable droplet impact, and anti-frosting performances

Robust superhydrophobic surfaces with excellent capacities of repelling water and anti-frosting are of importance for many mechanical components. In this work, wear-resistant superhydrophobic surfaces were fabricated by curing a mixture of polyurethane acrylate (PUA) coating and 1H,1H,2H,2H-Perfluorodecyltrichlorosilane (HFTCS) on titanium alloy (TC4) surfaces decorated with micropillars pattern, thus, composite functional surfaces with PUA coating in the valleys around the micropillars pattern of TC4 were achieved. Apparent contact angle on fabricated surfaces could reach 167°. Influences of the geometric parameters of micropillars pattern on the apparent contact angle were investigated, and the corresponding wear-resistant property was compared. Droplet impact and anti-frosting performances on the prepared surfaces were highlighted. An optimized design of surface texture with robust superhydrophobicity, controllable droplet impact, and anti-frosting performances was proposed. This design principle is of promising prospects for fabricating superhydrophobic surfaces in traditional mechanical systems.

Fabrication and peeling behavior of thermally conductive pressure-sensitive adhesive films with embedded graphite composite patterns

Thermal interface materials (TIMs) have been widely employed to address the thermal issues arising in electronics. Given that heat generated at heat sources is dissipated into heat sinks through TIMs, the softer they are, the more efficient the heat transfer is. In this paper, a thermally conductive pressure-sensitive adhesive (PSA) film (gr-PSA film) in which graphite composite patterns were embedded was fabricated and its thermal conductivity and peeling behavior were investigated. Because of its low storage modulus (2.4 × 104 Pa), a mixture of soft polyurethane acrylate, butyl acrylate, and 2-ethylhexyl acrylate was used to fabricate a PSA. The in-plane and through-plane thermal conductivity of the gr-PSA film were measured as 1.56 (±0.37) Wm−1K−1 and 0.25 (±0.03) Wm−1K−1, respectively. The peeling behavior of the gr-PSA tape was investigated by a 90° peel test and the results were compared with simulation results obtained by cohesive zone modeling implemented in the finite element method. Both results show that the peel force oscillated when the gr-PSA tape was peeled. Because the gr-PSA tape comprises alternating stiff and compliant segments, more force is needed peeling when bending the stiff segments.

Polymer-Stabilized Cholesteric Liquid Crystal Films with Double Reflection Bands Prepared Based on the Competition between Photopolymerization and Photoisomerization.

Composite colors have been widely found in nature. Herein, polymer-stabilized cholesteric liquid crystal (PSCLC) films with composite structural colors were prepared through a one-step photopolymerization approach. The CLC mixtures were prepared using a mixture of acrylates and a mixture of two chiral dopants. One of the chiral dopants is polymerizable, and the other one is photoisomerizable. After photopolymerization, the PSCLC films with double Bragg reflection bands were obtained on the surface of a substrate. The competition between the photopolymerization of the acrylates and the photoisomerization of the chiral dopant was proposed to drive the formation of the double reflection bands. Without oxygen inhibition, the polymerization of the acrylates near the substrate surface was carried out. However, due to oxygen inhibition, the polymerization of the acrylates near the air was retarded. Then, the photoisomerization of the chiral dopant was carried out prior to the polymerization of the acrylates. The wavelengths of the double reflection bands were tunable by changing the concentrations of the acrylates and chiral dopants and the polymerization temperature. Colorful patterns with composite structural colors were prepared, which were suitable for decoration and anti-counterfeiting.

Optimization of viscosity and composition of mixture of Cu powder and acrylate based resin for vat photopolymerization of metal components

Vat photopolymerization is a technique that uses photocurable resin having photoinitiator (PI) to initiate polymerization reaction when exposed to UV light. This process forms long chains polymers by combination of small chains monomers and oligomers. Vat photopolymerization depends on various parameters. This work focusses on the optimization of viscosity and composition of acrylate resin-Cu powder mixture for vat photopolymerization of metallic samples. Anycubic acrylate-based photopolymer resin and fine copper powder is used. Five configurations (50%Cu-50%resin, 55%Cu-45%resin, 60%Cu-40%resin, 65%Cu-35%resin & 70%Cu-30%resin) are formed to determine the highest possible density in each sample. These samples are then sintered in order to optimize the sintering parameters like debinding and sintering temperatures, oxygen and carbon contents. Then, the sample with maximum Cu density is used to optimize the viscosity of mixture using ethylene glycol as diluent. It is observed that ethylene glycol is useable as it effectively reduces the viscosity of resin without altering the chemical nature and curing time of photocurable resin. By equating the viscosity of optimized Cu-resin mixture with pure resin, difference in curing times is calculated for finite thickness of layer. This shows that 28% increase in curing time is observed when Cu-resin mixture is used as compared to pure resin. Sintering profile used is good in terms of debinding and sintering temperatures however hydrogen curing environment is essential to reduce carbon and oxygen contents in final samples.

Synthesis of Composite Polymer Particles by Seeded Emulsion Polymerization and Formation of Photonic Crystals Based on Them

Submicron composite particles with the core/shell structure are synthesized by the seeded emulsion polymerization of a mixture of various acrylates in the presence of a redox initiation system. The diameter, morphology, and surface structure of particles as well as their ability to self-assemble into 3D ordered thin-film structures are studied by scanning electron microscopy, FTIR spectroscopy, thermogravimetry, and dynamic light scattering. It is shown that under the used experimental conditions particles with a shell thickness of 10‒35 nm are synthesized. The effect of shell composition (in particular, the alkyl chain length of acrylate comonomers) on the morphology and structure of the surface layer of the obtained composite particles is traced.

Development of a Reactive Force Field for Simulating Photoinitiated Acrylate Polymerization.

Light-driven and photocurable polymer-based additive manufacturing (AM) has enormous potential due to its excellent resolution and precision. Acrylated resins that undergo radical chain-growth polymerization are widely used in photopolymer AM due to their fast kinetics and often serve as a departure point for developing other resin materials for photopolymer-based AM technologies. For successful control of the photopolymer resins, the molecular basis of the acrylate free-radical polymerization has to be understood in detail. We present an optimized reactive force field (ReaxFF) for molecular dynamics (MD) simulations of acrylate polymer resins that captures radical polymerization thermodynamics and kinetics. The force field is trained against an extensive training set including density functional theory (DFT) calculations of reaction pathways along the radical polymerization from methyl acrylate to methyl butyrate, bond dissociation energies, and structures and partial charges of several molecules and radicals. We also found that it was critical to train the force field against an incorrect, nonphysical reaction pathway observed in simulations that used parameters not optimized for acrylate polymerization. The parameterization process utilizes a parallelized search algorithm, and the resulting model can describe polymer resin formation, crosslinking density, conversion rate, and residual monomers of the complex acrylate mixtures.

Stratified and gradient films by evaporation-induced stratification of bimodal latexes. Potential of confocal and scanning electron microscopy for compositional depth profiling

In the field of bimodal latex film's formation, finding methods to quantify particle concentration profiles within the film thickness is a challenge. Herein the advantages and limitations of confocal fluorescence microscopy (CFM) and scanning electron microscopy (SEM) are presented. Films are prepared from a bimodal fluorescent acrylic mixture of large non-deformable particles and small deformable particles having high Péclet numbers. A fixed volume fraction of large particles (ΦL) in the dispersion is used with increasing volume fractions of small particles latex (ΦS). At low ΦS, a surface stratification of large particles occurs with thicknesses up to several micrometers, allowing detection by both CFM and SEM. Small particles form a stratified surface layer above a threshold ΦS value. Its thickness of less than 500 nm is evidenced only by SEM due to the resolution limit of the confocal scan. SEM is also able to reveal concentration gradients of large particles below the “small-on-top” stratified layer.

Construction of ternary mixture of long-chain acrylates for lower-temperature and higher-effect rotator phase photopolymerization

Low-temperature rotator phase photopolymerization is meeting great challenges due to the polymerization can’t occur after the rotator phase transform into crystalline phase, thus lower transition temperature between these two phases (TC-R) is needed. In this work, ternary mixture of hexadecyl acrylate (HDA), tetradecyl acrylate (TDA) and dodecyl acrylate (DDA) was constructed by drawing on the experiences of previous binary mixtures. Since the advantages of each component were combined, the mixture was proved possessing stable rotator phase, and the TC-R of the mixture achieved −38.11℃, which was 9.14℃ lower than the previous binary mixtures of octadecyl acrylate (ODA) and TDA. The photopolymerization kinetic of ternary mixture was investigated, which showed efficient photopolymerization at −30℃, moreover, the conversions between −25℃∼-15℃ were 6 %∼12 % higher than those of the binary mixture of ODA/TDA. In addition, it was found that the rotator phase photopolymerization of ternary mixture showed the properties similar to living polymerization, which performed post polymerization to realize complete conversion of monomers. Meanwhile, the feature of post polymerization demonstrated that besides TC-R, the spatial distance between adjacent monomers also significantly affect the conversion in rotator phase.

Multimaterial 3D Printing Technique for Electronic Circuitry Using Photopolymer and Selective Metallization

Herein, a 3D printing technique to enable the manufacturing of selectively plated polymer objects by photopolymer printing and copper metallization is presented. Metallized plastic has become popular in a number of industries due to its lightweight, flexibility of design, and cost‐effective fabrication. Common metallization techniques require multiple pretreatment steps, such as surface etching, sensitization/activation, and acceleration. The proposed method, by eliminating the sensitization step, allows selective metallization of 3D‐printed samples by direct plating. The method relies on the inclusion of silver seeds into a mixture of acrylate‐ and methacrylate‐based monomers and oligomers, which enables direct electroless copper metallization following 3D printing. Ag(I) ions act as catalytic sites for copper deposition. Copper films grown with embedded 2 and 4 wt% Ag(I) seeds reach thicknesses of 5.7 ± 1.2 and 7.7 ± 1.3 μm, respectively. Furthermore, printing with pristine and silver‐modified resins on the same sample allows selective plating: only the modified resin is plated leaving the pristine resin unaffected. A proof‐of‐concept temperature sensor is manufactured to demonstrate the performance of the printed interconnects.

Single‐Step Expeditious Synthesis of Diblock Copolymers with Different Morphologies by Lewis Pair Polymerization‐Induced Self‐Assembly

AbstractLewis pair polymerization has demonstrated its unique advantages and powerful capability in polymer synthesis. Here we employ strong nucleophilicN‐heterocyclic olefin (NHO) and bulky organoaluminum to construct a frustrated Lewis pair, which can realize the compounded sequence control (CSC) copolymerization and self‐assembly the mixture of dimethylaminoethyl acrylate and fluoride‐functionalized methacrylate into diblock copolymers (di‐BCPs) nano‐assemblies through polymerization‐induced self‐assembly in one‐pot, single‐step manner within minutes. These di‐BCPs were characterized by1H and13C NMR, GPC, DSC, and TEM. By utilizing appropriate solvophilic block and solvophobic block, such Lewis pair polymerization‐induced self‐assembly strategy enables the expeditious, room‐temperature synthesis of di‐BCP nanoparticles with different morphologies, including spheres, worms, vesicles, and even fibers, thus suggesting the great application potential of such method in the future.

Novel, High‐Resolution, Subtractive Photoresist Formulations for 3D Direct Laser Writing Based on Cyclic Ketene Acetals

AbstractDirect laser writing (DLW) is an innovative technology based on two‐photon polymerization processes which allow the 3D printing of architectures with arbitrary complexity at the (sub)micrometer scale. While most of the research interest in this field relies on additive manufacturing, subtractive approaches can be extremely helpful in nano/microfabrication, allowing the preparation of expendable scaffolds, replaceable parts, and for the protection of fragile structures. In this study, we show that the simple addition of 2‐methylene‐1,3‐dioxepane, a cyclic ketene acetal compound, to a series of different acrylate‐based photoresists results in functional formulations that allow the 3D‐printing of degradable poly(ester‐co‐acrylate) microstructures via DLW. These latter could be degraded reliably under mild conditions compatible with other photoresists and materials of common use in the fabrication of MEMS, thus opening new opportunities to design novel fabrication procedures. In addition, the possibility of using different acrylate mixtures without affecting the degradability, allows the users to choose between a broad range of properties for the printed structures to fit their needs, without affecting the degradability. Finally, the authors show the potential of these photoresists in the fabrication of shadowing masks on 3D objects and their selective degradation employing a photobase.

Janus particles by simplified RAFT-based emulsion polymerization process for polymer coating

We describe a simplified method to synthesize film forming polymer Janus particles by phase separation during RAFT-based free radical emulsion polymerization. Fully crosslinked snowman- or football-shaped polystyrene Janus particles (PSJPs) were first produced in a one-step batch process using amphiphilic triblock macro-RAFT copolymers as stabilizers. Such particles were in turn employed as seeds in a continuous emulsion polymerization in which a monomer mixture of methyl methacrylate (MMA) and butyl acrylate (BA) (1/1 by weight) was constantly injected into the reaction in the presence of a water soluble initiator. The added monomers wetted seed particle surface and their polymerization led to formations of 93-nm film forming single- or two-headed Janus particles. The resulted latex was successfully used to disperse and encapsulate solid calcite extender.Graphical abstract

Construction of Ternary Mixture of Long-Chain Acrylates for Lower-Temperature and Higher-Effect Rotator Phase Photopolymerization

Construction of Ternary Mixture of Long-Chain Acrylates for Lower-Temperature and Higher-Effect Rotator Phase Photopolymerization

Enhanced thermoelectric performance of UV-curable silver (I) selenide-based composite for energy harvesting

Thermoelectric (TE) composites, with photocured resin as the matrix and Ag2Se (AS) as the filler, are synthesized by a digital-light-processing (DLP) based 3D printer. The mixture of diurethane dimethacrylate (DUDMA) and isobornyl acrylate (IBOA) is used as a UV-curable resin because of their low viscosity and high miscibility. Scanning electron microscopy (FE-SEM) images confirm that the filler retains its shape and remains after the UV-curing process. After completing curing, the mechanical and thermoelectric properties of the composite with different AS contents were measured. The addition of the AS filler increases the thermoelectric properties of the cured resin. When the AS contents increase by 30 wt.%, the maximum power factor was obtained (~ 51.5 μW/m·K2 at room temperature). Additionally, due to the phonon scattering effect between the interfaces, the thermal conductivity of composite is lower than that of pristine photoresin. The maximum thermoelectric figure of merit (ZT) is ~ 0.12, which is achieved with 30 wt.% of AS at 300 K with the enhanced power factor and reduced thermal conductivity. This study presents a novel manufacturing method for a thermoelectric composite using 3D printing.

Development of new diacrylate monomers as substitutes for Bis-GMA and UDMA

ObjectiveBisphenol A-glycidyl methacrylate (Bis-GMA) and urethane dimethacrylate (UDMA) are widely used as the primary components of (meth)acrylic monomers. However, the use of Bis-GMA, which is a bisphenol A derivative, in dentistry is being questioned after bisphenol A was found to exhibit estrogenic activity. Although UDMA is being considered as a substitute for bis-GMA, the mechanical properties of cured resin composites containing UDMA are less than desirable. Therefore, in this study, we developed new alternative (meth)acrylic monomers to enhance the mechanical strength of cured composite resins. MethodsFive urethane acrylic monomers were synthesized in this study as (meth)acrylic monomer substituents to replace Bis-GMA and UDMA. The elastic modulus, strength, and breaking energy values of cured resins consisting of mixtures of the urethane acrylates and diluting monomers were determined using the three-point flexural test. The data obtained were analyzed using one-way ANOVA and the post-hoc Tukey HSD tests (p < 0.05). Viscosities of the urethane acrylic monomers were measured with a cone-plate viscometer. Refractive indices of the urethane acrylic monomers were determined with an Abbe refractometer. ResultsThe results of the three-point flexural tests revealed that the cured urethane acrylic monomer-based resin exhibited higher elastic modulus (up to 40%) and strength (up to 21%) compared to the cured UDMA-based resin. Viscosity and refractive index of the urethane acrylic monomers were between those of UDMA and Bis-GMA. SignificanceThe developed urethane diacrylates prepared from diisocyanates which have an aromatic or aliphatic ring, 1,3-bis(1-isocyanato-1-methylethyl)benzene (TMXDI), 1,3-bis(isocyanatomethyl)benzene (XDI), or norbornane diisocyanate (NBDI) are worth considering as alternative options of Bis-GMA and UDMA for restorative resin composites.