Polyurethane Acrylate Research Articles

Effect on 1-Butyl-3 Methylimidazolium Iodide Ionic Liquid in Nonedible Jatropha Oil-Based Polyurethane Acrylate. Tetrabutylammonium Iodide: Lithium Iodide-Based Gel Polymer Electrolyte for Dye-Sensitized Solar Cell Application

Improvement of the electrolyte ionic conductivity in DSSCs application is important as it contributes higher solar conversion efficiency. In this article, the polyurethane acrylate (PUA) gel polymer electrolyte (GPE) system was further improved with the addition of an ionic liquid in terms of ionic conductivity and also photovoltaic performance. The PUA GPE system enhanced with 6 wt % of 1-butyl-3-methylimidazolium iodide (BMII) ionic liquid was found to produce the highest improvement (ionic conductivity) compared to the different content of BMII. Ionic conductivity of (4.17 ± 0.01) × 10–4 S cm–1 was observed at room temperature with the addition of 6 wt % BMII in the GPE system. Moreover, the DSSC utilizing the GPE with 6 wt % BMII produces the highest solar conversion efficiency of (5.72 ± 0.14)% corresponding with the Jsc of (23.03 ± 0.2) mA cm–2 and Voc of (0.54 ± 0.01) V.

Preparation and Characterisation of Polyurethane Acrylate-Based Titanium Dioxide Pigment for Blue Light-Curable Ink.

Herein, a polyurethane acrylate-based TiO2 (PU-TiO2) was fabricated using a two-step method. First, a polyurethane prepolymer was prepared. Second, PU-TiO2 was prepared using amino-modified TiO2 (A-TiO2). The best synthesis process of the polyurethane prepolymer was when the reaction temperature was 80 °C, the reaction time was 3 h and the R-value of the polyurethane acrylate was 2. Next, the influence of the A-TiO2 content on the structure and performance of PU-TiO2 was examined. The analysis of the rheological properties of the PU-TiO2 ink indicated that its viscosity gradually increased as the A-TiO2 content increased. The tensile performance of film improved because of the presence of A-TiO2. The photo-polymerisation and photo-rheological performance indicated that the PU-TiO2 structure changed from a hyperbranched structure with TiO2 as the core to a segmented structure, as the A-TiO2 content was 3%.

Amphiphilic alginate stabilized UV-curable polyurethane acrylate as a surface coating to improve the anti-wrinkle performance of cotton fabrics

In this paper, a reactive amphiphilic alginate was prepared by an Ugi reaction using 4,4′-diaminostilbene-2,2′-disulfonic acid and its structure was analyzed by FT-IR and 1H NMR measurement. Subsequently, it was utilized as emulsifier to prepare polyurethane acrylate (PUA) emulsion and the colloidal properties including zeta potential, droplet size distribution and stability were evaluated. The results showed that the PUA emulsion by this modified alginate had better colloidal stability than that by original one. Finally, stable PUA emulsion was used for surface treatment of cotton fabrics in a UV curing process to improve their anti-wrinkle performance. By measuring the wrinkle recovery angle, it was found the anti-wrinkle properties of cotton fabrics were significantly improved with the increase in the amount of modified alginate. In addition, this anti-wrinkle finishing method was found to have many advantages such as low temperature, low yellowing as well as high washing resistance.

Highly transparent and resilient urethane-methacrylate siloxane composite for hard, yet stretchable protective coating

Although foldable electronic devices have been commercially available for some time now, flexible protective coating with sufficient reliability is yet to be achieved. The integration of polyurethane acrylate and an organic-inorganic (O-I) siloxane hybrid is proposed in this study as a promising protective coating, where both high strength and stretchability could be achieved to allow for the needed reliability for foldable electronics. In this work, a urethane-methacrylate siloxane hybrid (U-MSH) composite was fabricated by a physical blending of methacrylate-functionalized oligosiloxane and acrylate terminated urethane prepolymer followed by curing. The U-MSH composite demonstrates excellent performance in terms of optical (e.g., transmittance, Abbe number, UV stability) and mechanical properties (e.g., resilience under compression, tension, and scratch). These outstanding properties can be attributed to the synergetic effect of the combined polyurethane acrylate and O-I siloxane hybrid. Excellent reliability of U-MSH coating film is successfully demonstrated using an outward-bending test, suggesting that U-MSH has great potential as a protective material for flexible electronics.

Strain rate dependent mechanical properties of 3D printed polymer materials using the DLP technique

Three-dimensional (3D) printing technology shows great potential for applications in aerospace engineering, biomedical engineering, and conceptual model preparation. Digital light processing (DLP) 3D printing technology is often used to produce fine components for these applications due to its high precision and efficiency. In this paper, the mechanical properties of DLP printed polyurethane acrylate resin were investigated. Different strain rates were accomplished by using a universal testing machine for quasi-static loading and a Hopkinson bar for dynamic loading. The experimental results show the obvious stain rate effect, anisotropy, and ductile-to-brittle transition for the 3D printed polymers. In addition, the results reveal that anisotropy decreases with the increase in strain rate. The fracture patterns for specimens subjected to different loadings were observed using an optical microscope. The results show that the tensile fracture in the vertical (interlayer) direction is flatter than that in the parallel (in-plane) direction. The specimens subjected to parallel compression show symmetric convex deformation and cracking, while those subjected to vertical compression exhibit asymmetric single-ended cracking. A one-dimensional (1D) phenomenological constitutive model was used to fit the experimental data, and this constitutive model was shown to describe well the mechanical behaviors of the 3D printed materials under uniaxial tension and compression using different strain rates.

Improving mechanical and water vapor barrier properties of the parylene C film by UV-curable polyurethane acrylate coating

Abstract Parylene C (PC) films have been widely used in many fields, such as metal anti-corrosion, electronic packaging, etc. However, the relatively poor mechanical properties and the deteriorated water barrier performance due to the easy fracture under external stress have restricted their application. It is a relatively simple and good method to maintain the water vapor barrier and enhance the mechanical properties of PC film by covering a flexible coating on its surface. In this work, a new polyurethane acrylate (PUA) coating was prepared and coated on the PC film by ultraviolet curing technology to form the PC/PUA composite film. The results showed that the PUA coatings could improve the water vapor barrier and mechanical properties of the PC film simultaneously. The water vapor transmittance rate was reduced from 1.1791 g·(m−2·day−1) of the original PC film to 0.5636 g·(m−2·day−1) of the PC/PUA composite film. The elongation at break and the impact energy were increased to 48.36% and 41.67%, respectively, which would widen the application of PC films in the fields of flexible electronics or smart wear.

Facile Fabrication of Three-Dimensional Hydrogel Film with Complex Tissue Morphology.

In this study, we proposed a simple and easy method for fabricating a three-dimensional (3D) structure that can recapitulate the morphology of a tissue surface and deliver biological molecules into complex-shaped target tissues. To fabricate the 3D hydrogel film structure, we utilized a direct tissue casting method that can recapitulate tissue structure in micro-/macroscale using polydimethylsiloxane (PDMS). A replica 3D negative mold was manufactured by a polyurethane acrylate (PUA)-based master mold. Then, we poured the catechol-conjugated alginate (ALG-C) solution into the mold and evaporated it to form a dried film, followed by crosslinking the film using calcium chloride. The ALG-C hydrogel film had a tensile modulus of 725.2 ± 123.4 kPa and maintained over 95% of initial weight after 1 week without significant degradation. The ALG-C film captured over 4.5 times as much macromolecule (FITC-dextran) compared to alginate film (ALG). The cardiomyoblast cells exhibited high cell viability over 95% on ALG-C film. Moreover, the ALG-C film had about 70% of surface-bound lentivirus (1% in ALG film), which finally exhibited much higher viral transfection efficiency of GFP protein to C2C12 cells on the film than ALG film. In conclusion, we demonstrated a 3D film structure of biofunctionalized hydrogel for substrate-mediated drug delivery, and this approach could be utilized to recapitulate the complex-shaped tissues.

Influence of the composition of macromolecular diols on the rheology and water absorption of polyurethane acrylate emulsions

AbstractWaterborne modified polyurethane (PU) dispersions with different macromolecular diols as soft segments were prepared by the self‐emulsifying method, and then compounded with the acrylate monomers, the polyurethaneacrylate composite emulsion (PUA) with the core‐shell structure was prepared by emulsifier free emulsion polymerization. The effects of the type and ratio of macromolecular diols in the soft segment on the particle size and distribution, rheological properties, adhesion, water absorption and thermal properties of the PUA emulsion were studied. The results showed that the particle size of PUA decreased, and the shear resistance and heat resistance of PUA were enhanced with the addition of polypropylene glycol. According to the water absorption rate of PUA emulsion, it was found that adding poly‐1,4‐butanediol adipate glycol and poly(caprolactone) diol with more hydrophobic groups could improve the water resistance of PUA dry film, and the minimum water absorption value was 0.68%.

Improved adhesion of polyurethane-based nanocomposite coatings to tin surface through silane coupling agents

Conformal coatings with higher adhesion strength is crucial for mitigating the growth of whiskers from the pure tin (Sn) or Sn-rich surfaces of the Pb-free electronics. Silane coupling agents have the ability to form a durable bond between polymeric coatings and metallic materials. The main goal of this paper is to investigate the effect of silane agents on the adhesion behavior of polyurethane (PU), polyurethane acrylate (PUA) and both coatings filled with silicone rubber (SR) nanoparticles on the tin solder pads. It was found that an isocyanate-based silane provided excellent adhesion for PU and PU + SR coatings and an acrylic-based silane for PUA and PUA + SR coatings on the tin surface. This was due to the reaction bond formation between the silane coupling agent and the coating. Hence, the selection of silane coupling agents with the organofunctional group similar to the coating material is crucial to improve the adhesion properties of the coating.

Efficient inductively heated shape memory polyurethane acrylate network with silane modified nanodiamond@Fe3O4 superparamagnetic nanohybrid

Multifunctional magnetic shape memory polymer (SMP) nanocomposites with high sensitivity was synthesized through inclusion of silane functionalized [email protected]3O4 (S-NDF) hybrid nanoparticle into polycaprolactone (PCL) based polyurethane acrylate (PUA) matrix followed by in situ crosslinking of the matrix. Highly biocompatible and superparamagnetic nanodiamond(ND)@Fe3O4 nanohybrids were synthesized through in situ co-precipitation method. The morphological analysis suggested that S-NDFs filled PUAs (2 to 9 wt% loadings) well interacted with both soft and hard domains of the matrix. The base polymer and the nanocomposites presented excellent shape fixity ratio (above 97%) and shape recovery ratio (above 99.5%) in hot water. Furthermore, PUA/S-NDF nanocomposites with nanohybrid loading of 9 wt% exhibited excellent shape recovery rate (above 96%) in a very small magnetic field (H = 0.76 kA.m−1) as well as faster magnetic responsiveness compared to Fe3O4 loaded nanocomposites. Moreover, PrestoBlue cell viability assay suggested biocompatibility of the base polymers and the nanocomposites.

An anti-shrinkage model of an ultraviolet-curing coating filled with hollow polyurethane acrylate microspheres

The application of ultraviolet (UV)-curing coatings in precision devices is restricted because of their high shrinkage performance. In this study, hollow polyurethane acrylate (PUA) microspheres are filled into a mixed tripropylene glycol diacrylate (TPGDA) coating with different volume fractions to regulate shrinkage ratios of the coating, where hollow PUA microspheres with different diameters and thicknesses are synthesized using the microfluidics technology. The thickness-dependent mechanical properties of PUA thin films (the same thickness with the shell of each microsphere) are obtained by combining in-situ tensile and nanoindentation experiments with finite element (FE) method. The empirical formula between geometrical parameters (diameter, shell thickness, volume fraction) of hollow PUA microspheres and shrinkage ratios of the TPGDA coating filled with these PUA microspheres are derived using the present representative volume element (RVE) method. Checking against the results of UV-curing shrinkage experiments shows the current empirical formula has high accuracy. This study provides a physical insight into modulating their shrinkage ratios of different UV-curing materials.

Nanopatterned Polymer Molds Using Anodized Aluminum Templates for Anti-Reflective Coatings.

This work introduces a facile geometry-controlled method for the fabrication of embossed and engraved polymeric moth-eye-inspired nanostructures in imprinting molds using anodic aluminum oxide (AAO) templates, resulting in a novel anti-reflective transparent coating. The moth-eye nanostructures are prepared directly on the surface of a flexible polyethylene terephthalate (PET) substrate. As a prerequisite procedure, a UV-curable polyurethane acrylate resin is spun on the PET. The shape of the moth-eye nanostructures can then be adjusted by controlling the size and shape of the nanopores in the AAO templates. Both embossed and concaved polymer moth-eye nanostructures were successfully mounted on a PET substrate. Embossed polymer replica molds were prepared using the AAO master templates in combination with an imprinting process. As revealed by field-emission electron microscope (FE-SEM) images, conical nanopatterns in the AAO template with a diameter of ~90 nm and a depth of ~100 nm, create a homogeneous embossed morphology in the polymer moth-eye nanostructure. The polymeric molds with the depths of 300 and 500 nm revealed the amalgamated structures in their apexes. In addition, a dip-imprinting process of the polymeric layers was implemented to yield a concaved mold by assembly on the surface of the 100 nm embossed polymer mold substrate. Considering that the embossed structures may be crumbled due to their protuberant shapes, the concaved geometries can have an advantage of stability in a certain application concerning physical degradation along with a higher transmission by ~2%, despite somewhat nonuniform structure. The experimental and theoretical results of this study indicate that this polymer layer has the potential for use in anti-reflective coating applications in transparent films.

Preparation and properties of UV-curable waterborne silicon-containing polyurethane acrylate emulsion

The non-toxic and environmental protection characteristics of water-based coating make it has a good development prospect, but its poor water resistance and stability have attracted widespread attention. A type silicon-containing polyurethane acrylate core-shell structure emulsion was prepared by using in-situ self-emulsification, and it was applied to fabric-based substrates to study the influence of the different distribution of groups on the surface of the coating on the interfacial properties of the fabric-based coating. The silicon-containing polyurethane acrylate was synthesized by grafting unsaturated double bond with silane coupling agent which was characterized by FTIR and 1H NMR. The stability of the emulsion was tested by dynamic light scattering technique. The distribution of latex particles and the core-shell structure were observed by transmission electron microscopy (TEM). After the introduction of vinylsiloxane, the particle size of polyurethane acrylate emulsion decreased from 180.3 nm to 111.7 nm, and the emulsion samples could be stored for 6 months stably. The surface properties and morphology of the cured polyurethane acrylate film samples were evaluated by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The thermal stability of cured film was analyzed by thermogravimetry (TG). In addition, emulsion samples with different silicone contents were coated on different fabric-based substrates (cotton fiber, PET and PP), and the fabric based coatings were cured quickly by utilizing the characteristics of fast UV curing and low energy consumption. The low surface energy organosiloxane was easier to migrate to the surface of the material, which increased the surface tension of the fabric based coatings. The water contact angles of the coatings interface were greater than 100°, showed good hydrophobic performance. In addition, the emulsion was dipped into the fabric-based substrate and it was found that the content of polar groups (-COO−) on the surface of the fabric-based coatings gradually increases along with increase of the concentration of the emulsion and the number of dips, and the organosiloxane originally on the surface of the coating was coated on the inner layer, made the hydrophobic performance of the coating decreased and when the emulsion concentration increased to 0.5 g/mL or the dip coating reached 5 layers, the interfacial performance of the coating changed from hydrophobic to hydrophilic. And the fabric based coatings with adjustable interfacial properties were obtained.

A modified TEGDMA-based resin infiltrant using polyurethane acrylate oligomer and remineralising nano-fillers with improved physical properties and remineralisation potential

ObjectivesThis study aimed to modify an experimental triethylene glycol dimethacrylate (TEGDMA) based resin infiltrant using PUA oligomer and two remineralising fillers, including fluorohydroxyapatite (FHA) and fluoride-doped bioactive glass (FD-BG), to improve the mechanical and physical properties and induce remineralising potential. Materials and methodsThe polyurethane acrylate oligomer (PUA) was synthesised and characterised. Experimental resin infiltrant was prepared by mixing 10% of synthesised PUA with 88% TEGDMA. Water contact angle, penetration coefficient, and penetration depth were then measured. The FHA and FD-BG fillers were synthesised and characterised. To prepare nano-filled resin infiltrant, 5% of each powder was mixed with the prepared resin infiltrant. The prepared resin infiltrants were characterised to evaluate their degree of conversion, mechanical properties, water sorption, and solubility. The ion release of filled resin was also assessed. The non-infiltrated and infiltrated enamel specimens underwent fourteen days of pH-cycling, and a surface microhardness was done to assess the resistance to demineralisation. ResultsThe results showed that the addition of PUA to TEGDMA increased the mechanical properties and decreased water sorption and solubility. The addition of synthesised FD-BG fillers to resin infiltrant significantly improved the resistance to demineralisation of enamel samples compared with other groups (p ≤ 0.001). The FHA fillers also improved the resistance to demineralisation; however, the produced changes were not statistically meaningful (p > 0.05). ConclusionsBased on the results, the PUA+TEGDMA+ FD-BG/FHA composite can be used as an alternative material for pure TEGDMA in enamel infiltration approaches owing to its better mechanical properties, lower water sorption and solubility, and also remineralisation potential. Clinical SignificanceA resin infiltrant with remineralisation potential, lower water sorption and solubility and higher mechanical properties may enhance the management of early caries lesions.

Rubber Seed Oil-Based UV-Curable Polyurethane Acrylate Resins for Digital Light Processing (DLP) 3D Printing.

Novel UV-curable polyurethane acrylate (PUA) resins were developed from rubber seed oil (RSO). Firstly, hydroxylated rubber seed oil (HRSO) was prepared via an alcoholysis reaction of RSO with glycerol, and then HRSO was reacted with isophorone diisocyanate (IPDI) and hydroxyethyl acrylate (HEA) to produce the RSO-based PUA (RSO-PUA) oligomer. FT-IR and 1H NMR spectra collectively revealed that the obtained RSO-PUA was successfully synthesized, and the calculated C=C functionality of oligomer was 2.27 per fatty acid. Subsequently, a series of UV-curable resins were prepared and their ultimate properties, as well as UV-curing kinetics, were investigated. Notably, the UV-cured materials with 40% trimethylolpropane triacrylate (TMPTA) displayed a tensile strength of 11.7 MPa, an adhesion of 2 grade, a pencil hardness of 3H, a flexibility of 2 mm, and a glass transition temperature up to 109.4 °C. Finally, the optimal resin was used for digital light processing (DLP) 3D printing. The critical exposure energy of RSO-PUA (15.20 mJ/cm2) was lower than a commercial resin. In general, this work offered a simple method to prepare woody plant oil-based high-performance PUA resins that could be applied in the 3D printing industry.

CQDs-MoS2 QDs loaded on Dendritic fibrous Nanosilica/Hydrophobic waterborne polyurethane acrylate for antibacterial coatings

Since bacterial infections are the cause of many diseases, death, and disability, considerable attention has been paid to the preparation of antibacterial surfaces. Anti-adhesive and bactericidal synergistic surfaces show promising antimicrobial applications due to the removal and killing effect of microorganisms. Herein, we proposed a leather coating surface with hydrophobic and photocatalytic antibacterial properties. Dendritic fibrous nanosilica (DFNS) loaded with carbon quantum dots (CQDs) and MoS2 QDs (DFNS@CQDs-MoS2) nanoparticles were successfully prepared, which exhibited excellent photocatalytic antibacterial activity. Specifically, the DFNS@CQDs-MoS2 nanoparticles exhibited antibacterial activities of 99.98%, 95.35%, and 99.99% against Escherichia coli, Staphylococcus aureus, and Aspergillus niger, respectively. Then, hydrophobic waterborne polyurethane acrylate (HWPUA) was developed, which exhibited enhanced bacterial adhesion resistance. Furthermore, the HWPUA/DFNS@CQDs-MoS2 coating completely inactivated the residual bacterial cells. Therefore, the synergistic antibacterial coatings developed in this work could have potential applications as antibacterial surfaces.

Eco-friendly polyurethane acrylate (PUA)/natural filler-based composite as an antifouling product for marine coating.

In the current study, the polyurethane acrylate (PUA) polymer was synthesized by the addition reaction between an isophorone diisocyanate (IPDI) and 2-hydroxyethyl acrylate and cured by polyol. Different properties of the synthesized PUA were determined through diverse analysis methods. The polyurethane acrylate (PUA)/natural filler-based composite (rhizome water extract of Costus speciosus) was prepared as an antifouling agent. The results revealed that the lowest weight loss percentages were detected at 2 wt% PUA/natural filler composite loadings with Escherichia coli (ATCC 23,282) and Pseudomonas aeruginosa (ATCC 10,145). The decreased weight loss percentage may be attributed to the well dispersed natural composite resulting in a slippery surface that can prevent fouling adhesion. It was concluded that the PUA/natural filler composite might be considered an eco-friendly and economical solution to the biofouling problem. KEY POINTS: • A novel strategy for anti-biofouling. • A new composite reduced Gram-negative bacteria.

A Highly Controlled Organic-Inorganic Encapsulation Nanocomposite with Versatile Features toward Wearable Device Applications.

Ultraviolet-curable polyurethane acrylate (PUA) materials can be used in a number of important applications spanning from microfluidics, surface patterning to wearable technology. For the first time, the potential of encapsulation of modified zirconia (ZrO2 ) nanoparticles is reported in PUA-based hybrid films aimed to facilitate profoundly enhanced hardness and refractive index. By successfully manipulating the interfacial reaction conditions between ZrO2 nanoparticles and PUA film, the PUA-based nanocomposites exhibit an ultrahigh hardness of 9 and superior refractive index of 1.64 (589.3 nm). The outcomes obtained pave the way for seamless application of nanozirconia/PUA as a potent encapsulating material that provides structurally morphable, water resistant, and optically transparent light emitting diodes toward wearables devices in healthcare.

Fabrication of Photothermal Film for Deicing Process Based on Gold Nano-Aggregate Encapsulated Yolk-Shell Structure

Ice accumulation on vessels, airplanes, or on the off-shore plants surfaces causes major accidents and difficulties in operation. Therefore, highly efficient and environmentally friendly materials for use as deicing surfaces are in continuous demand. Accordingly, photothermal materials have gained enormous attention owing to their outstanding performance in the removal of ice. Herein, a gold nano-aggregate yolk-shell structure (GNA-YS) was introduced as a deicing material. GNA-YS was homogeneously dispersed in photocurable polyurethane acrylate and used to fabricate a highly efficient and sunlight-responsive GNA-YS film. Upon irradiation with an 810 nm light-emitting diode (LED) (135 mW cm−2), the temperature of the GNA-YS film increased by approximately 70 °C within 2 min, which rapidly (within 6 min) melted the accumulated ice. Moreover, the GNA-YS film exhibited a temperature increase of 15 °C in a refrigerator under LED illumination for 1 min. Additionally excellent stability was confirmed through repeated experiments. The newly developed deicing GNA-YS film has prospective applicability in vessels or airplanes.

Covalent bonding effects on spectral, photophysical and generation properties of indocarbocyanine dyes in polyurethanes

Spectral, photophysical and generation properties of symmetrical cationic cyanine dyes have been investigated in the polyurethane matrices, similar by the structure, but different by the polymerization method. The cyanine dye doped polyurethane, synthesized by a polycondensation reaction, provides laser active elements with significantly improved photostability, efficiency and operation lifetime, compared to those for the polyurethane acrylate matrix, hardened by a radical photopolymerization method. Changing the liquid (ethanol) medium to polymers causes an increase of fluorescence quantum yield and efficiency. For the first time, covalent bonding between a cyanine dye and a polyurethane has been studied, and high fluorescence quantum yield and generation efficiency have been observed.