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Polyurethane prepolymers: an efficient dispersant core for sublimation inkjet inks
Abstract
In this study, the modification of toluene diisocyanate “TDI”-based prepolymers was performed using three different polyols (trimethylol propane “TMP,” glycerol and castor oil). The prepared modified prepolymers were terminated using amino-polyether (Jeffamine M-2070) and maleic acid-modified polyethylene glycol “PEG 1000” to obtain dispersing agents for water-based disperse dye inkjet inks. Dispersants T1–T5 (based on TMP), dispersants G1–G5 (glycerol) and dispersants C1–C5 (castor oil) were characterized using FTIR to monitor the reaction progress. Inkjet inks made using these dispersants were characterized by particle size, dynamic surface tension, rheology profile and accelerated stability against commercial dispersant. The results revealed that glycerol and TMP-based dispersants provided optimum performance as compared to commercial standard, while castor oil-based dispersants failed the wettability and dispersion stability tests.
... An effective dispersing agent operates as a lubricant that lowers interactions and frictions between particles, leading to decreased viscosities, indicative of a welldispersed system. In contrast, an inadequate dispersant exhibits a reduced level of coverage on the particles' surfaces, thereby promoting inter-particle interaction, which can result in elevated viscosity levels based on the number of exposed surfaces present [36][37][38]. ...
... 47) dyne/cm, DA3(37)(38)(39)(40) dyne/cm, DA4 (45-548) dyne/cm, DA5 (47-51), DA6 (46-48) dyne/cm., DA7 (41-43) dyne/cm and DA8 (39.5-42) dyne/cm. This is due to the fact that in all samples, the majority of the dispersant was adsorbed on the titanium dioxide pigment surface. ...
... These dispersions showed excellent stability, self-adhesive performance, and washing and rubbing fastnesses [13]. AS et al. prepared a series of WPUs for dispersing dye inkjet inks and investigated the effects of different polyols (trimethylolpropane, glycerol and castor oil) on the dispersion properties [18]. ...
Disperse dyes are hardly soluble in water and are usually milled with large numbers of dispersants in the dye industry. A branched waterborne polyurethane (WPU) as a dispersant with different side chain lengths (WPU350, WPU550 and WPU750) was synthesized through an acetone process. The effects of the side chain length on the stability and dispersibility of disperse dyes were particularly discussed and analyzed. The results showed that due to their special comb-like structures, these WPUs were able to achieve good dispersive ability for disperse dyes and WPU550 had the best dispersibility through steric hindrance and electrostatic repulsion on the surface of dyes. In addition, WPU was further employed to prepare the dispersion to dye the polyester fabric. These dispersions with WPU not only demonstrated an improved K/S value, wet and dry rubbing fastness and soaping fastness but also had better dispersing and dyeing performance than commercial dispersants.
Purpose
This paper aims to study the physical and chemical characteristics of inkjet titanium dioxide inks for cotton fabric digital printing.
Design/methodology/approach
Different dispersing agents through the reaction of glycerol monooleate and toluene diisocyanate were prepared and then performed by using three different polyols (succinic anhydride-modified polyethylene glycol PEG 600, EO/PO Polyether Monoamine and p-chloro aniline Polyether Monoamine), to obtain three different dispersing agents for water-based titanium dioxide inkjet inks. The prepared dispersants were characterized using FTIR to monitor the reaction progress. Then the prepared dispersants were formulated in titanium dioxide inkjet inks formulation and characterized by particle size, dynamic surface tension, transmission electron microscopy, viscosity and zeta potential against commercial dispersants. Also, the study was extended to evaluate the printed polyester by using the prepared inks according to washing and crock fastness.
Findings
The obtained results showed that p-chloro aniline Polyether Monoamine (J) and succinic anhydride modified polyethylene glycol PEG 600 (H) dispersants provided optimum performance as compared to commercial standards especially, particle size distribution data while EO/PO Polyether Monoamine based on dispersant was against and then failed with the wettability and dispersion stability tests.
Practical implications
These ink formulations could be used for printing on cotton fabric by DTG technique of printing and can be used for other types of fabrics.
Originality/value
The newly prepared ink formulation for digital textile printing based on synthesized polyurethane prepolymers has the potential to be promising in this type of printing inks, to prevent clogging of nozzles on the printhead and to improve the print quality on the textile fiber.
Recent years have seen a significant increase in the use of inkjet technology for printing on textile fabrics. Typical inkjet printed textile products included curtains, large advertising posters, flags and banners. So, in this research we focused on using different formulations of Textile inkjet inks based on different types of dispersing agent which prepared, evaluated and applied on the polyester fabric. The properties of the prepared ink formulations were analyzed by measuring viscosity, surface tension, and particle size. The purpose of this study was to investigate the influence of the dispersing agent chemistry on the behavior of inkjet inks characteristics used for inkjet printing on polyester textiles, the study including the effect of using different doses of the different dispersing agents and study of the time of milling. Difference of chemistries of dispersing agents give viscosity, Static Surface Tension, Dynamic Surface Tension in accepted range but it largely cleared in the particle size distribution which tend to performance of the inks on the print head and prevent clogging of nozzles. Also the study extend to evaluate the polyester printed by using the prepared inks according to light fastness, washing fastness, Alkali Perspiration Fastness and Crock Fastness which have been have good results agreement with this type of inkjet inks for textile printing.
The preparation of disperse inks for direct inkjet printing was carried out using disperse dye, dispersant (TD-1109, hydrophilic polyacrylic acid block copolymer), wetting agent (diethylene glycol and ethylene glycol), water-based polymers (polyvinyl alcohol (PVA) or waterborne polyester), deionized water, etc. The suitability of disperse inks for polyester fabrics was assessed via measurement of conductivity, pH, particle size surface tension and viscosity. The theological behavior of disperse inks was evaluated by rotational viscometry; the disperse inks had the characteristics of a Newtonian fluid. The inkjet printability of disperse inks was investigated by monitoring droplet formation dynamics, where the viscosity and surface tension of disperse ink were 2.78 mPa s and 33.28 mN m-1, respectively. The disperse ink has excellent ejection performance. The printing accuracy of disperse inks was evaluated by inkjet printing quality of lines on untreated polyester fabrics. The fastness properties of printed polyester fabrics were also evaluated and they presented excellent color fastness. Compared with different printed polyester fabrics, the polyester fabrics printed with disperse ink made from water-based polymers have high color strength (K/S) and saturation (C*) values.
Research presented in this article focuses on the preparation of functional dispersions for inkjet printing of nanoparticles as sensitive layers. The stable suspensions of MOx(M = Ti, Zn) were prepared using gum arabic (GA) and Solsperse? 40000 (SO) as dispersants. A special attention was paid to the monitoring of particle size evolution during the planetary ball milling of dispersions, so that optimum ratio between milling time and particle size can be determined. After adjusting the printing parameters, prepared inks were printed on the flexible PET substrate with interdigitated electrodes (IDE). Films printed with TiO2 ink stabilized by GA exhibited highly cracked surface which resulted in low current values, whereas ZnOink stabilized by SO yielded crack-free surface and much higher current values. All investigated samples showed linear current behaviour in the range from -5 to 5 V, indicating formation of ohmic contacts between electrodes and nanoparticles, but ZnO ink produced the highest current values. Gas sensing properties, tested at room temperature at several humidity levels and for different types of alcohols, revealed that printed sensor exhibits modest sensitivity for low humidity levels and slightly higher affinity towards methanol gas. Photo sensitivity measurement showed very high photocurrent values with strong potential for optoelectronic applications.
Dyeing auxiliaries play an important role in the determination of the final dyeing quality. The formation of additional complexes with dyes and auxiliary agents enhances the exhaustion of dyes on textile substrates. For aqueous-based dyeing, dye auxiliaries such as chelating agents, dispersing agents, leveling agents, electrolyte, pH control agents, and surfactants form complexes with the dye on natural and synthetic fibers. A growing awareness of the impact of industrial pollution on the environment became crucial for the dyeing industry in the closing decades of the twentieth century. These chapters discuss the characteristics of dyeing chemicals and how auxiliary substances can assist in achieving outstanding dyeing performance.
Inkjet printing is an excellent printing technique and an attractive alternative to conventional technologies for the production of flexible, low-cost microelectronic devices. Among many parameters that have a significant impact on the correctness of the printing process, the most important is ink viscosity. During the printing process, the ink is influenced by different strains and forces, which significantly change the printing results. The authors present a model and calculations referring to the shear rate of ink in an inkjet printer nozzle. Supporting experiments were conducted, proving the model assumptions for two different ink formulations: initial ink and with the addition of a dispersing agent. The most important findings are summarized by the process window regime of parameters, which is much broader for the inks with a dispersing agent. Such inks exhibit preferable viscosity, better print-ability, and higher path quality with lower resistivity. Presented results allow stating that proper, stable graphene inks adjusted for inkjet technique rheology must contain modifiers such as dispersing agents to be effectively printed.
A series of chains of triblock amphiphilic copolymers were synthesized by atom transfer radical polymerization (ATRP) techniques and post modified to polymeric dispersant for waterborne paint. Poly(butyl acrylate (BA))-b-poly(hydroxy ethyl methacrylate (HEMA))-b-poly(methyl methacrylate (MMA)) triblock copolymers having predetermined molecular weights were synthesized by ATRP using CuBr, 2-bromoisobutyrate, and pentamethyldiethylenetriamine as a catalytic system in dioxane at 80 °C. The copolymers were further reacted with cyclic chlorophosphate and triethyl amine to form dispersible modified poly(BA-HEMA-MMA). The synthesized copolymers were structurally evaluated by Fourier transform infrared, 1H NMR, 31P NMR, gel permeation chromatography (GPC), energy dispersive X-ray spectroscopy, and their hydroxyl equivalent, respectively. The surface activity of modified copolymers as dispersing additives was investigated by the surface tension analysis and wetting ability test. The ability of additives to function as wetting and dispersing agents was evaluated by analyzing their mechanical, optical, chemical, and rheological properties of water-based paints at different pigment volume concentrations. The effects of the chain length of copolymers on dispersibility and optical properties were studied. The optical properties of paints suggested that the dispersibility of modified poly (BA)-b-poly (HEMA)-b-poly (MMA) (MPBHM) increased with an increase in the molecular weight of the copolymer.
The intermolecular and intramolecular noncovalent interactions involving π-aromatic compounds have attracted increasing attention over the last decades in chemistry, biology and material sciences. In this review, we discuss contemporary computational studies on the nature and strength of H-π, π-π, and anion-π interactions. We emphasize how modern quantum theoretical approaches ahead of experiment can provide insight into the design of new materials and devices by tuning the π-interactions in cooperative and competitive manners. Usefulness of such approaches towards designing new materials is demonstrated with some examples of molecular recognition/sensing, self-assembly/engineering, receptors, catalysts, supramolecules, graphene, and other two-dimensional (2D) materials/devices.
Chemical and physical parameters of the aqueous polyurethane dispersion (PUD) were studied after the synthesis. A prepolymer mixing process with a limited-chain extension step was used in order to examine the polymer and dispersion behavior with respect to the ageing time. Measurements of free isocyanate groups were performed with the aid of Fourier transform infrared spectroscopy (FT-IR). The pseudo-first-order kinetics of NCO disappearance was proposed and the value of the corresponding constant was determined. Additionally, particle size, particle size distribution, pH, conductivity and molecular mass were monitored and compared.
Stability of the pi-pi stacking interactions in the ben parallel to substituted-ben and ben parallel to substituted-COT complexes was studied using the computational quantum chemistry methods (where ben and COT are benzene and cyclooctatetraene, parallel to denotes pi-pi stacking interaction, substituted-ben and substituted-COT are benzene and cyclooctatetraene which substituted with four ethynyl-X groups, respectively, and X = OH, CH3, H, F, CF3, CN and NO2). In these complexes electron-withdrawing substituents lead to larger binding energies and electron-donating ones lead to weaker interactions compared to X = H. There are meaningful correlations between the Hammett constants and binding energies. The atoms in molecules (AIM) analysis shows that formation of these complexes is accompanied by increase in the electron charge densities at the ring critical points of the substituted-ben and substituted-COT rings which leads to increase/decrease of the pi-pi stacking interactions in the ben parallel to substituted-ben/ben parallel to substituted-COT complexes. The charge transfer occurs from benzene to substituted-ben in the ben parallel to substituted-ben complexes and from substituted-COT to benzene (with the exception of X = CN) in the ben parallel to substituted-COT ones. Nuclear magnetic resonance calculations demonstrate that interactions of the more aromatic substituted-ben/less anti-aromatic substituted-COT rings with benzene in the ben parallel to substituted-ben/ben parallel to substituted-COT complexes can be helpful to enhance strength of the pi-pi stacking interactions. Thus, regardless of ring size, the pi-pi stacking interaction is an aromatic-aromatic interaction and pi electron cloud properties of interacting rings affect on the strength of this interaction.
Photometric measurements of the daytime chromaticity and luminance of retroreflective sign materials were made both in the laboratory and in the field. These instrument measurements were compared with daytime perceptual judgements of color properties made by human observers in the field. Hue, saturation, and brightness were determined for four different types of retroreflective sheeting materials and one diffuse material at four quadrants of each color area for six different colors specified in the Code of Federal Regulations for use on street and highway traffic control signs.
Disperse dyes are hardly soluble in water which in commercial form are usually milled in the presence of large amounts of dispersing agents. The type and amount of these materials can affect the disperse ability of dyes in aqueous media. In this manuscript, stability of prepared dye dispersions in the presence of various surface active agents and additives were investigated. In this respect, various dispersing agents such as Irgasol DAM, Asutol 644, Dispertane MF and Irgasol P800 were used to prepare dye dispersions in milling stage. Furthermore, the formulations of dye dispersions were obtained by adding β-cyclodextrin, urea and wetting agent. The dye dispersion quality was determined by its filtering property, turbidity and centrifuging method. The obtained results proved the stability of dispersion containing of Irgasol DAM, wetting agent and β-cyclodextrin as dispersing auxiliaries in dyeing process of disperse dye on polyester fabrics in high temperature method was the highest related to other dispersions. From the experimental results, it was found out that stability of prepared dispersions was improved by the presence of β-cyclodextrin. Also, utilization of β-cyclodextrin in formulations of dye dispersions caused to increasing of stability of dispersion in the dyeing of polyester fabrics.
Vegetable oils are excellent but very heterogeneous renewable raw materials for polyols and polyurethanes. This review discusses the specific nature of vegetable oils and the effect of their structures on the structure of polyols and polyurethanes. One section is dedicated to polyols for rigid and flexible foams and methods of their preparation such as direct oxidation of oils, epoxidation followed by ring opening, hydroformylation, ozonolysis, and transesterification. The next section deals with preparation and structure‐property relationships in polyurethanes from different groups of polyols, different isocyanates, and different degrees of crosslinking. The final section covers the environmental aspects of bio‐based polyurethanes, i.e., thermal stability, hydrolytic stability, and some aspects of biodegradability.
The preparation of microemulsified disperse inkjet inks was carried out and the effect of the surfactant used as dispersing
agents on the properties of the inks was studied. The dispersing agents used were anionic conventional and non-conventional
surfactants and a gemini type surfactant. The properties studied were surface tension, pH, conductivity, viscosity and the
particle size distribution. The use of the gemini type and the two non conventional surfactants even in submultiple amounts
resulted in a significant increase in the ink stability.
KeywordsSurfactant–Disperse–Inkjet inks–Gemini surfactant–Non-conventional surfactant–Microemulsion
In textile inkjet printing, it is important to understand the design theory of ink jet printing ink. In this study, according to the solubility parameters of printing ink components (humectant, penetrant, pH regulator, viscosity regulator and deionized water), twelve different complex solvents were designed to prepare disperse ink. By observing the particle size, stratification, rheological property and viscosity of the prepared inks, the ink meeting the requirements was subsequently selected. The low field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) analyses were used to analyze the water distribution and structure information of the ink at the micro level, which provide opportunities to subsequently interpret the macro properties (fluidity) of ink. The ink before and after filtration was tested using an ultraviolet-visible spectrophotometer (UV), and the content of the disperse dye in the ink was observed to be reduced after filtration. The viscosity of the ink before and after filtration were also analyzed. The viscosity of the ink was noted to significantly decrease after filtration, which indicated that the content of the disperse dye in the ink exhibited a vital influence on the ink viscosity. LF-NMR was applied to study the stability of ink (1a, 1c, 3a, 3c, 4a, 4c, 5a, 5c, 6a and 6c) in cold and hot environments. No new peak was found in T 2 relaxation time inversion spectra of disperse ink, which indicates that there is no physical or chemical change among the components in disperse ink. The voltage of the driving waveform was adjusted and ejection performance of different inks was characterized. The results indicated linear driving voltage and ligament length of the inks. Different fixation temperatures (160 ℃-190 ℃) were used to optimize the fixation temperature of the printed fabrics, and 180 ℃ was determined to be the optimal fixation condition. Finally, the color fastness of the printed fabric was tested and analyzed. The findings revealed that the color fastness of the printed fabric met the use requirements.
The present article explores the usage of functionalized urethane of robust affinity to pigment through the reaction of polyurethane adduct with different types of polyether in order to improve the pigment dispersion stability, color and wetting properties. The raw materials and prepared dispersants were characterized by FTIR, GPC, Non-volatile content. The properties and dispersing ability of the dispersants were also investigated by measuring ink viscosity, Rheology, surface tension and particle size. The prepared polymeric dispersants were employed as dispersing agents for solvent-based inkjet ink application. The adhesion and color properties of prepared ink also were studied. All dispersants possessed high gloss comparing to blank after storage stability and low particle size and surface tension except PUD 5, 6, all dispersants showed no negative affect on adhesion of ink on printed PVC film and possessed excellent dispersing ability and rheological properties indicated by low ink viscosity for most commonly used cyan pigment C.I. 15:4.
In this study, we propose a dye–monomer interaction force measurement technique based on atomic force microscopy (AFM) to predict the performance of polymeric dispersants. Cantilevers modified with functional monomers such as styrene, N-butyl acrylate (BA), and 2-(N-phthalimido)ethyl methacrylate (PEMA) were used to characterize the interaction force between these functional monomers and a target dye (Disperse Blue 359). The interaction forces of each monomer—styrene, BA, and PEMA—with Disperse Blue 359 were measured as 10.75 nN, 7.06 nN, and 21.31 nN, respectively, and their trend was consistent with dipole-moment values obtained from density function theory (DFT) calculations (μ(styrene) = 0.0001, μ(PEMA) = 2.3158, μ(Disperse Blue 359) = 3.0368). We synthesized a series of model polymers containing specific functional monomers (CoPS10, CoBA, CoPPEMAs) with similar molecular weights, molecular-weight distributions, and acid contents and compared their actual performance with that predicted from interaction force measurement data. The results were well correlated with the interaction force measurement data. The effect of the PEMA content on dye dispersion stability was also investigated; the results indicated that both the PEMA content and the type of dye-interacting group greatly influenced the characteristics of the dispersion.
The castor plant has been cultivated for thousands of years, providing a useful source of medicine, lamp fuel, and lubricant long before petroleum came into wide use. The oil content of castor seed ranges from 45% to 60%, with most cultivars closer to 50% oil content. The presence of the hydroxy fatty acid ricinoleate [(9Z, 12R)-12-hydroxyoctadec-9-enoate] in the oil at a level of 90% imparts unique physical and chemical properties that give the oil value as a chemical feedstock. This midchain hydroxy group results in hydrogen bonding among the triacylglycerols that carry the 2 or 3 ricinoleoyl chains. The intermolecular interaction results in viscosity that is significantly greater than that of other commodity seed oils, providing superior properties for use in lubricants and greases. The susceptibility of the hydroxyl group to substitution or elimination provides a wide range of derivatives. The chemical interaction of the hydroxy group separated by one methylene from a carbon-carbon double bond supports several cleavage reactions that provide a collection of industrially useful chemicals. Products derived from castor oil have been in use for centuries, long before "biobased" was a buzzword or requirement for meeting sustainable product regulations.
Disperse dyes are very hydrophobic molecules which are usually milled in the presence of large amounts of dispersing agents (synthetic surfactants) in their commercial form. In this study the synthetic surfactants are substituted by phosphatidylcholine liposomes in the dye preparation, in order to use natural and biological surfactants. The turbidity ratio was calculated to assess the dispersion behavior of different liposome-dispersed dye preparations compared with commercial dye forms. Results indicate that liposomic preparations diminish the aggregation of dye molecules that normally occurs at high temperatures. Our findings demonstrated the potential efficacy of liposomes as natural surfactants which can be applied to disperse dye formulations to dye polyester fibers with good dye exhaustion and washing fastness. This environmentally friendly biological surfactant, phosphatidylcholine, duly structured as liposomes, can substitute high amounts of synthetic dispersing agents in disperse dye formulations.
The stability of dye dispersions in the presence of ethoxylated sorbitan lauryl and oleyl esters were reported and compared with dye dispersions containing a conventional dispersing agent, i.e. naphthalene sulfonic acid methylene-bis sodium salt (NSAB). The optimum operating conditions obtained using a central composite design and stability of dye dispersions were evaluated by a turbidimetry method. Results showed that the dose of surfactants and the temperature of operation were important factors in preparing stable dye dispersions. Also, the best conditions for preparing dye dispersions were as follows: dose of surfactant 0.05 g, temperature 25 °C and time 5 min. In addition to, findings indicated that both of the used surfactants had better performance in dispersing the dyes in water. However, ethoxylated sorbitan oleate had better efficiency relative to other used dispersing agents. The performance of both sorbitan esters were compared with NSAB. The results indicated that they can create stable dye dispersions in aqueous media and have approximately the same effectiveness with NSAB. In this series, although oleate ester had a better performance than the laurate, the difference in performance of using dispersing agents was not significant. This finding was confirmed by the results of the particle size analysis of dye dispersions.
The effects of the addition of polyethylene glycol (PEG) within the coated film on the water vapor permeability and waterproof
properties of the foam-coated fabrics were investigated. Foaming solutions added with PEG had lower surface tension than those
without, and the viscosity and stability of the foaming solution varied with PEG of different molecular weight. When PEG is
of 1,000 daltons (PEG 1000), the viscosity and stability of the foaming solution was the highest among molecular weights ranging
from 400 to 16,000, whereas the surface tension was the lowest. The stability would rise proportionally with viscosity if
the viscosity of the foaming solution is between 13,610 cps and 13,960 cps. When PEG 1000 was added, the particle size of
the foaming solution was smaller, followed by PEG 600. But when PEG 4000 or ethylene glycol (EG) was added, the particle size
was bigger. The introduction of PEG 1000 to the foaming solution produced better water vapor permeability and waterproof properties.
Fabrics coated with foaming solution, to which PEG 1000 was added, had smaller and more micropores in the coated film. Coated
film without the addition of PEG had less micropores, and that with the addition of EG or PEG 4000 had large pores with non-homogenous
pore sizes. These results were confirmed by SEM observation.
A key contact in the active site of an aminoglycoside phosphotransferase enzyme (APH(3')-IIIa) is a pi-pi stacking interaction between Tyr42 and the adenine ring of bound nucleotides. We investigated the prevalence of similar Tyr-adenine contacts and found that many different protein systems employ Tyr residues in the recognition of the adenine ring. The geometry of these stacking interactions suggests that electrostatics play a role in the attraction between these aromatic systems. Kinetic and calorimetric experiments on wild-type and mutant forms of APH(3')-IIIa yielded further experimental evidence of the importance of electrostatics in the adenine binding region and suggested that the stacking interaction contributes approximately 2 kcal/mol of binding energy. This type of information concerning the forces that govern nucleotide binding in APH(3')-IIIa will facilitate inhibitor design strategies that target the nucleotide binding site of APH-type enzymes.
Direct Sublimation Inkjet Printing as a New Environmentally Friendly Approach for Printing on Polyester Textiles
- M R Alihoseini
- Khani
- Mr
- M Jalili
- B Shokri