UV-curing Technology Research Articles

Synthesis, mechanical properties and iron surface conservation behavior of UV-curable waterborne polyurethane-acrylate coating modified with inorganic carbonate

The performances of UV-curable waterborne polyurethane-acrylate (WPUA) composite modified with nano calcium carbonate (NCA) were highlighted in this work. The γ-methacryloxy propyl trimethoxyl silane (KH-570) and polysorbate 80 (Tween-80) were used to enhance interfacial interaction between NCA and WPUA matrix. Transmission electron microscopy (TEM), particle size analysis and Fourier transfer infrared (FT-IR) spectrometry were employed to examine the micromorphology and the variation of function group of modified nano calcium carbonate (MNCA). Three different WPUA oligomers were investigated to obtain the optimized R value (the molar ratio of –NCO:–OH) via in situ polymerization and anion self-emulsification process. Results showed that WPUA displayed excellent film-forming ability and mechanical properties when R value was 2.2:1.0. These UV-curable WPUA films modified with MNCA (UV-MNCA/WPUA) were prepared through environmentally friendly UV-curable technology and investigated by thermogravimetric (TG) analysis, scanning electron microscope (SEM), X-ray diffractometer (XRD) and FT-IR. UV-MNCA/WPUA-3-3 film had the best overall performances with MNCA-2 and UV-WPUA at the mass ratio of 3.6%. Finally, the experimental results demonstrated that the as-obtained UV-curable coating had outstanding conservation effect to iron surface, providing a promising way for protection of iron cultural relics.

Environment-stable solar window modules encapsulated with UV-curable transparent resin

We demonstrate a practical and robust encapsulation for environment-stable solar window modules based on multi-crystalline silicon solar cells with ultra-violet-curable optically clear resin (OCR) films. Compared to encapsulation with polyvinyl butyral (PVB) films, OCR films significantly improved the operational stability in solar window modules following a harsh damp heat test, at 85 °C of temperature and 85% of relative humidity for 1 k h. Such advance can be realized by suppressed chemical reactions with water molecules in OCR films. We further investigate the optical characteristics of PVB and OCR encapsulation films using ultraviolet/vis. spectrophotometer and Fourier-transform infrared spectroscopy measurements to support the claim. We believe that this is the first module-level demonstration (400 mm×400 mm) of solar windows encapsulated with OCR films fabricated below 60 °C by using UV curing technology, which exhibit a power conversion efficiency of ∼10%, even after undergoing the damp heat tests.

Electrically conductive palm oil-based coating with UV curing ability

Abstract Environmentally friendly products are gaining popularity recently, in line with the increasing global demands for green technology. UV-curable coating is one of them since it involves minimal, if any, emission of volatile organic compounds during the curing process. Besides, UV curing technology enables coatings to be cured within a much shorter time compared to the thermal curing process. The aim of this study is to produce an electrically conductive UV-curable coating which is environmentally friendly. Polyaniline is a polymer with excellent electrical conductivity and known to exhibit anti-corrosion properties through passivation. However, polyaniline itself is not a good coating binder, as it tends to produce a brittle film with poor adhesion properties. Therefore, in this work, palm oil-based polyester binder was synthesized and blended with polyaniline to produce an electrically active coating with improved film adhesion properties. The alkyd resin was formulated with a considerable amount of maleic acid formulation in order to render it UV curable. Both alkyd and polyaniline were characterized using FTIR, 1 H NMR, TGA, and UV-Vis. Some of the tests carried out to investigate the film properties of the coatings included the pencil hardness test, adhesion tape test, water and chemical resistant test, conductivity, and thermal stability. In addition, corrosion studies of the coatings on mild steels were determined using open circuit potential (OCP) values, Tafel analysis and electrochemical impedance spectroscopy (EIS).

One Step Synthesis of Uniform SnO2 Electrode by UV Curing Technology toward Enhanced Lithium-Ion Storage.

A uniform anode material composed of ultrasmall tin oxide (SnO2) nanoparticles with an excellent lithium-ion (Li-ion) storage performance is obtained for the first time through one step UV curing technology. The diameter of ∼3 nm-sized SnO2 particles is uniformly dispersed in the styrylpyridinium (SbQ) polymer because of its photo-cross-linking property. The in situ cross-linking of SbQ polymer not only assist synthesis of uniform ultrasmall SnO2, but act as a strong adhesion binder on SnO2 nanoparticles, thereby effectively accommodating the volume expansion of SnO2 anodes during cycling process. The uniform electrode exhibits substantially higher specific capacity and longer cycling stability compared with the SnO2 nanoparticles electrodes treated by traditional PVDF-mixing method. A stable specific capacity of 572.5 mA h g-1 of the SnO2 electrode derived from UV curing technology is obtained at a current density of 0.2 C (156.2 mA g-1) after 150 cycles. Even at high rate of 5 C (3905 mA g-1), the electrode still demonstrates specific capacity of 440.2 mA h g-1. Therefore, the scalable and low-cost synthetic approach described herein can readily be extended to other nanomaterials electrodes to improve their lithium-storage properties.

Polymeric Thioxanthones as Potential Anticancer and Radiotherapy Agents.

Thioxanthone (TX) and its derivatives, which are widely used as photoinitiators in UV curing technology, hold promising research interest in biological applications. In particular, the use of TXs as anticancer agent has recently been manifested as an outstanding additional property of this class of molecules. Incorporation of TX molecules into specially designed polymers widens their practical use in such applications. In this study, two water-soluble, biocompatible, and stable polymers, namely poly(vinyl alcohol) and poly(ethylene glycol), possessing TX moieties at the side chains and chain ends, respectively, are prepared and used as anticancer and radiotherapy agents. The findings confirm that both polymers are potential candidates for therapeutic agents as they possess useful features including water-solubility, radiosensitizer effect, and anticancer activity in a polymeric scaffold.

Preparation and property of UV-curable polyurethane acrylate film filled with cationic surfactant treated graphene

The preparation of nanocomposite films composed of UV-curable polyurethane acrylate (PUA) and modified graphene were demonstrated in this paper. Cetyl trimethyl ammonium bromide modified graphene (CTAB-G) was prepared via intercalation of cationic surfactant and subsequently incorporated into PUA by UV curing technology. Fourier transform infrared spectra, wide-angle X-ray diffraction, scanning electron microscopy and transmission electron microscopy were used to characterize the structure and morphology of CTAB-G, as well as CTAB-G/PUA nanocomposite films. The results revealed that the CTAB-G sheets were layer-by-layer structure and dispersed uniformly in PUA matrix. Thermal gravimetric analysis showed that the thermal stabilities of UV-curable PUA nanocomposite films in this work were much higher than that of PUA nanocomposites previously reported. Dynamic mechanical analysis indicated that the dynamic mechanical properties of nanocomposite films were greatly enhanced in the presence of modified graphene sheets. In addition, the CTAB-G/PUA nanocomposite films exhibited improved dielectric properties and electrical conductivities compared with the pure PUA.

Preparation and physical properties of functionalized graphene/waterborne polyurethane UV-curing composites by click chemistry

Functionalized graphene nanoplatelets (f-GNS) were modified with (3-mercaptopropyl)trimethoxysilane (MPTMS) to enhance their compatibility with the polyurethane coating matrix. The results of Fourier transform infrared spectroscopy, AFM, Raman and XRD showed that the MPTMS was successfully attached onto the surface of the graphene nanoplatelets. Functionalized graphene/waterborne polyurethane acrylate (f-GNS/WPUA) nanocomposites were fabricated by UV-curing technology. The SEM and TEM images indicated that f-GNS could be well dispersed in the polymer matrix and improved the interfacial adhesion. With the incorporation of 1 wt% f-GNS, the thermal decomposition temperature of the composites was increased by 25 °C. Meanwhile, the conductivity, hydrophobicity and tensile strength were increased. When the load was further increased, the performance of the composites showed varying degrees of reduction. However, the dielectric loss tangent (tan δ) could be maintained at 0.08 or less and the electromagnetic shielding factor of the composites reached from 5 to 36 dB, showing a good electromagnetic shielding effect at a high content (2.5 wt% f-GNS). It was considered that f-GNS could disperse in the waterborne polyurethane well and crosslink with the polyurethane. © 2016 Society of Chemical Industry

Synthesis and characterization of nano‐modified permeability membrane

Novel high‐flux and fouling‐resistant pervaporation membranes were synthesized. The nano‐SiO2/polyurethane acrylate (NPUSA) membrane was prepared by 2,4‐toluene diisocyanate, hydroxy alkyl silicone oil (Tech‐2120), and hydroxyethyl acrylate and cross‐linked with the monomer pentaerythritol triacrylate (PETA) by UV curing technology. Nano‐SiO2, which has a large amount of hydroxyl groups that can make a reaction with the isocyanato (NCO), was used as a cross‐linking agent as well as an inorganic silicone precursor to generate an inorganic network. An inorganic organosiloxane network (SiOSi) was generated in the membrane by the electrophilic addition of carbamate between hydroxyl groups and isocyanato. The impact of nano‐SiO2 to NPUSA membrane was investigated using Fourier transform infrared spectrometer (FTIR), gel permeation chromatography, thermal gravimetric analysis, and atomic force microscopy (AFM). FTIR analysis confirmed the presence of the SiOSi network in the membrane, and AFM analysis confirmed the homogeneous distribution of this network throughout the membrane. The performance of NPUSA/PETA membrane was also compared with the commercially available membranes poly(vinyl alcohol)/poly(acrylonitrile) and polydimethylsiloxane and was found to be more resistant to compaction and with better permeability. Copyright © 2015 John Wiley & Sons, Ltd.

Ultraviolet-curable polyurethane acrylate nanocomposite coatings based on surface-modified calcium carbonate

Abstract Polyurethane acrylate/surface-modified colloidal calcium carbonate (PUA/SCaCO3) nanocomposite coatings were successfully prepared via a UV-curing technology. The structural and morphological features of the PUA/SCaCO3 nanocomposites were characterized by Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscope (FE-SEM), atomic force microscopy (AFM), and wide angle X-ray diffraction (XRD). The physical properties were strongly dependent upon chemical and morphological structures that originated from differences in SCaCO3 loading. A critical SCaCO3 concentration was observed for the evolution of both the structure and physical properties of the PUA/SCaCO3 nanocomposites as a function of SCaCO3 content. The thermal stability was measured by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively, and displayed some enhancement with the incorporation of SCaCO3 into PUA. Although the nanomechanical properties increased up to 3 wt% SCaCO3 content, they decreased due to lack of interfacial interaction with high SCaCO3 loading. Most importantly, the water uptake and water vapor transmission rate (WVTR) varied from 5.51 to 1.78 wt% and 28.9 to 19.9 g/m2 day, respectively, exhibiting significant enhancement in water resistance. The results clearly reveal that the performance of UV-curable PUA/SCaCO3 nanocomposites is strongly dependent on organically-modified colloidal SCaCO3 nanoparticles.

Fluorine-containing photocurable hybrid coatings via anhydrous sol-gel method

In this study, fluorine-doped photocurable hybrid coatings were prepared by combining UV-curing technology with an anhydrous sol–gel method. First, methacryloxymethyl triethoxysilane (MEMO) was hydrolyzed via an anhydrous sol–gel process. Then MEMO was mixed with acrylic oligomers and predetermined amounts of fluoroacrylate resin. UV curable hybrid coatings were applied on corona-treated plexiglass substrates. The addition of fluorine showed a significant impact on the properties of the coatings. As the fluorine content was increased in the formulations, flame retardancy and the contact angle values of the coatings increased. It was found that the optical transmittance of the coatings was higher than 95%. The surface morphology of the hybrid films was characterized by scanning electron microscopy (SEM). The chemical composition of the surface of the coatings was identified by energy dispersion spectrum (SEM–EDS) technique. SEM studies indicated that inorganic particles were dispersed homogenously throughout the organic matrix. J. VINYL ADDIT. TECHNOL., 2014. © 2014 Society of Plastics Engineers

Reduction of the Water Wettability of Cellulose Film through Controlled Heterogeneous Modification

A facile method had been applied to introduce hydrophobic properties to cellulose materials by incorporation of polyurethane acrylate (PUA) prepolymers into the porous structured cellulose matrix through dip-coating; then, PUA prepolymers were cured around interconnected cellulose fibers under UV light, encapsulating a cellulose matrix with a hydrophobic polymer shell. The characterization of the composite films confirmed the success of the heterogeneous modification, and the chemical structure of the cellulose matrix was preserved. The composite films integrated the merits of cellulose and PUA resin, but the highly hydrophilic behavior of cellulose has been reduced. Contact angle measurements with water demonstrated that the composite films had obvious hydrophobic properties and an obvious reduction in the water uptake and the permeability toward water vapor gas at different relative humidity was also observed. The transmittance of the composite films at 550 nm was about 85%. The thermal and mechanical properties of the composite films were improved when compared with that of PUA resin. The obtained composite based on cellulose and UV curing technology was a good choice for the development of biomass materials with modified surface properties.

Cationic UV-Curing: Technology and Applications

This paper reviews the field of cationic UV-curing and reports recent progress made in understanding the fundamental chemistry and in technology applications. Radiation curing technologies are expanding rapidly on an industrial scale and interest in cationic photopolymerizations has advanced rapidly. In particular, the cationic UV-curing process presents additional benefits, including: the absence of air inhibition, a “dark-curing” reaction, low levels of toxicity and irritation, and a lower volume shrinkage during photopolymerization. In this review, a large number of papers and patents are reviewed and critically discussed specifically with respect to the application of cationic UV-curing technology in the field of coatings, composites, adhesives, and inks.

Fabrication of optically clear acrylic pressure–sensitive adhesive by photo-polymerization: UV-curing behavior, adhesion performance, and optical properties

Acrylic pressure–sensitive adhesives (PSAs) with 2-phenoxy ethyl acrylate (PEA) were polymerized using UV-curing technology. This study examined the effects of PEA content and UV dose. The photo-polymerization behavior of the pre-polymer was examined by viscosity measurements, real-time Fourier transform infrared spectroscopy, and photo-differential scanning calorimetry. The curing behaviors of the acrylic PSAs were investigated by shrinkage test, a modular advanced rheometer system, and gel content. differential scanning calorimetry and Advanced Rheometric Expansion System were used to characterize the acrylic PSAs. Adhesion performances were measured by probe tack, peel strength, and shear adhesion failure temperature. The optical properties of acrylic PSAs were examined by UV–visible spectroscopy and prism coupler. The PEA content had a larger effect on improving the optical properties, than did the UV dose. The transmittances of the acrylic PSAs with <75% PEA were >95%. The refractive indices of the acrylic PSAs increased with increasing PEA content, due to its high refractive index, >1.5, which affected the overall refractive indices, particularly in the visible region.

A study on the forming simulation and formability of three dimensional bevel embossing of columnar array microstructures

This study conducted three dimensional bevel embossing forming simulation and forming experiment. Using the columnar array microstructure as the cavity insert, along with the self-developed linear control three dimensional bevel embossing system and UV-curing technology, this study carried out the microstructure three dimensional bevel embossing forming process. First, geometric methods were employed to deduce the three dimensional bevel embossing forming mathematical equations for input into Matlab programming software in order to simulate three dimensional bevel embossing results. Next, three dimensional bevel embossing experiment was conducted to discuss the simulated and experimental microstructure formability and process parameters. The experimental results suggested that, the simulated three dimensional bevel embossing results using forming equations are accurately close to the three dimensional bevel embossing experimental results, and the self-developed linear control three dimensional bevel embossing system has perfect embossing formability and high stability.

UV-cured clay/based nanocomposite topcoats for wood furniture: Part I: Morphological study, water vapor transmission rate and optical clarity

The combination of UV-curing technology and nanotechnology has been applied in this study to synthetize by in situ photopolymerization method, UV-cured topcoats based on acrylate matrix reinforced (1 and 3wt%) individually with three different types of commercial organoclays, namely Cloisite 10A (C10A), Cloisite 15A (C15A) and Cloisite 30B (C30B). The morphological study was quantitatively and qualitatively performed by X-ray diffraction (XRD) and by transmission electron microscopy (TEM) respectively. Water vapor transmission rate (WVTR) and optical clarity of these nanocomposites were also assessed. TEM images obtained for those UV-cured coatings respectively reinforced with C10A and C30B showed that the absence of diffraction peaks in XRD patterns of these samples do not mean necessarily a possible exfoliation of their layered silicate nanoparticles by acrylate matrix (AM). Indeed, according to TEM images, we believe that C30B was not dispersible in the AM; while both UV-cured nanocomposites containing C10A and C15A respectively seemed to have an intercalated morphology regardless of the clay content (1 and 3wt%). All the organoclays used in this study have had an effect on both WVTR and optical clarity. The tortuous path created by the organoclay dispersed into the AM, by retarding the progress of water vapor through a sample, best explain the decrease of WVTR whereas the decrease of optical clarity is due to the light scattering by organoclay particles. Based on the above mentioned results, among the three different reinforcing agents used in this study, C10A appears to be the ideal organoclay for practical application.

Study on Abrasion Resistance of UV Curing System

UV curing technology, with high efficiency, energy saving, environmental protection and other advantages, has rapidly developed into a new technology in digital imaging area. In order to avoid the printing graphic damaged during the circulation of printing press, the requirement of the rub resistance of UV curing system is higher and higher. Aiming to explore the rub resistance of UV-curable systems, different samples were prepared by changing the types and content of the prepolymer, reactive monomer and anti-abrasion, using the principles of the mass loss method abrasion meter test samples after curing wearable, analyze the effect of the variety and the content of prepolymer, reactive monomer and the type of wear-resistant additives on the rub resistance of UV-curable systems. The best abrasion UV curing system was determined by formulations experimental method. The results show that:The prepolymer and wear-resisting additives have great influence on the abrasion resistance of UV-curable systems. The active monomer, which can improve the rub resistance of the UV contribute to varnish, has certain influence on the UV-curable systems. The result is suitable for all the UV-curable systems, and it will contribute to the improvement of wear resistance of UV curing system.

UV-Curable Functionalized Graphene Oxide/Polyurethane Acrylate Nanocomposite Coatings with Enhanced Thermal Stability and Mechanical Properties

Functionalized graphene oxide (FGO) was synthesized and subsequently incorporated into polyurethane acrylate (PUA) by UV curing technology. The structural and morphological features of FGO/PUA nanocomposite coatings were characterized by FTIR, XRD, and TEM. The results showed that FGO sheets were uniformly dispersed into the PUA matrix and formed the strong interfacial adhesion with PUA owing to the formation of the cross-linking networks between FGO and PUA after UV curing. The incorporation of FGO effectively enhanced the thermal stability and mechanical properties of host polymer. The initial degradation temperature of the PUA composite with 1.0 wt % FGO was increased to 316 °C from 299 °C for neat PUA. Meanwhile, the storage modulus and tensile strength of the PUA composite with 1.0 wt % FGO were also improved by 37% and 73%, respectively, compared with those of neat PUA. The slight increase in glass transition temperature (Tg) of the composites was observed upon the incorporation of FGO. By contrast,...

Study on photostabilization in situ of reactive hindered amine light stabilizers applied to UV-curable coatings

Four monomeric reactive hindered piperidinol derivatives, such as 4-methacryloyl-1,2,2,6,6-pentamethyl-piperidinyl (MPMP), 4-acryloyl-1,2,2,6,6-pentamethyl-piperidinyl (APMP), 4-methacryloyl-2,2,6,6-tetramethyl-piperidinyl (MTMP), and 4-acryloyl-2,2,6,6-tetramethyl-piperidinyl (ATMP), were applied as reactive hindered amine light stabilizers (r-HALS) in UV-curable coatings. The effect of r-HALS on the UV-curing kinetics of the UV-curable coatings of different monomers or oligomers has been previously investigated. Polymer coatings were prepared by means of UV-curing technology; experiments were conducted manually on photoaging indoors, monitoring the Yellowness Index (YI) in the photooxidation process, and adding r-HALS. The experiments were done to review its photoprotection effect on UV-cured coatings. Subsequently, they were compared with typical commercial HALS through parallel experiments to investigate the photooxidation aging mechanism of polymer coatings, and the effective concentration was determined from the changing circumstances of YI, thus comparing their differences in photostabilizing effect in situ of the polymer coatings.

Cell Growth on In Situ Photo-Cross-Linked Electrospun Acrylated Cellulose Acetate Butyrate

In this study, electrospinning was combined with UV curing technology for producing in situ photo cross-linked fibers from methacrylated cellulose acetate butyrate (CABIEM). ECV304 and 3T3 cells were seeded on electrospun fibrous scaffolds. Collagen modified CABIEM fibers were also prepared for improving cell adhesion and proliferation. Cross-linking and the morphology of the fibers were characterized by ATR–FTIR spectrometry and environmental scanning electron microscopy (ESEM). The cytotoxicity of the fibers was examined using the MTT cytotoxicity assay. According to the results, electrospun fibrous scaffolds are non-toxic and cell viability depends on the amount of collagen. It was found that cell adhesion and cell growth were enhanced as the collagen percentage was increased.

Accompanying of parameters of color, gloss and hardness on polymeric films coated with pigmented inks cured by different radiation doses of ultraviolet light

In the search for alternatives to traditional paint systems solvent-based, the curing process of polymer coatings by ultraviolet light (UV) has been widely studied and discussed, especially because of their high content of solids and null emission of VOC. In UV-curing technology, organic solvents are replaced by reactive diluents, such as monomers. This paper aims to investigate variations on color, gloss and hardness of print inks cured by different UV radiation doses. The ratio pigment/clear coating was kept constant. The clear coating presented higher average values for König hardness than pigmented ones, indicating that UV-light absorption has been reduced by the presence of pigments. Besides, they have indicated a slight variation in function of cure degree for the studied radiation doses range. The gloss loss related to UV light exposition allows inferring that some degradation occurred at the surface of print ink films.