Properties Of Waterborne Polyurethane Research Articles

Enhancement of the adhesion strength of water-based ink binder based on waterborne polyurethane

Series of Waterborne Polyurethanes (WPUs) were synthesized by molecular structure design, using sodium 2-((2-aminoethyl) amino) ethanesulfonate (AAS) as the post-chain extender, and selecting poly-1,4-butanediol adipate (PBA) and isophorone diisocyanate (IPDI) as the soft segment and hard segment, respectively. The effects of changes in PBA molecular weight and AAS content on the properties of WPUs were investigated through analysis of adhesion, mechanical properties, and thermal properties. The result showed that the T-peel strength, shear strength, and adhesion of the film reached 7.75 ± 0.48 N/mm, 1.81 ± 0.08 MPa, and 1.45 ± 0.11 MPa, respectively, due to the higher hydrogen bond density in the molecular structure when the Mn of PBA was 2000 g/mol. Based on the selection, the introduction of sulfamate increased the urea bond content of the system, further increasing the intramolecular hydrogen bond density. When the content of AAS was 1.0 wt%, the T-peel strength, shear strength, and adhesion of the film were increased to the highest values of 10.63 ± 0.30 N/mm, 2.08 ± 0.09 MPa, and 2.41 ± 0.08 MPa, respectively. Therefore, WPU has a wide range of applications in the field of water-based ink binders due to its high adhesive strength.

Interpenetrating network structure design and corrosion resistance of high‐performance waterborne polyurethane coating modified by epoxy resin and functionalized graphene oxide

AbstractTo obtain graphene oxide (GO) derivatives‐based waterborne polyurethane (WPU) composite coatings with high anti‐corrosion performance, microstructure, dispersion and interfacial adhesion of the coatings are key factors to consider. In this study, the waterborne polyurethane modified by epoxy resin (WEPU) and graphene oxide (GO) derivatives was synthesized by copolymerization, and its synergistic effect on the anti‐corrosion properties of waterborne polyurethane (WPU) coating was investigated. For this purpose, the isophorone diisocyanate (IPDI) was grafted to the surface of GO. Then, the functionalized GO (iGO) was uniformly dispersed in the WEPU emulsions by a prepolymer method, which was attributed to strong interaction between iGO and WEPU, as proved by FTIR spectra and SEM images. The deterioration process of WEPU and iGO‐WEPU coatings during the long‐term immersion in 3.5 wt% NaCl solution was investigated by electrochemical impedance spectroscopy (EIS). The results indicated that the introduction of well dispersed iGO nanosheets into WEPU system enhanced the corrosion protection performance to substrate. Significantly, for the 0.9 wt% iGO nanosheets reinforced WEPU composite films, the contact angle value of iGO‐WEPU composite films (94.7°) reaches the highest in comparison with that of pure WEPU film (88°), thus remarkably improving the water barrier property of iGO‐WEPU coating.

Effect of chain extenders with different functionalities on the properties of single-component waterborne polyurethane ink binders.

Waterborne polyurethane (WPU) dispersions were prepared by post-chain extension and crosslinking reactions using 2-[(2-aminoethyl)-amino]ethyl sulfonic acid sodium (AAS), diethylenetriamine (DETA), triethylenetetramine (TETA) and AAS/DETA as post-chain extenders, and their influence on the properties of WPUs was studied. Results showed the introduction of trifunctional DETA chain extenders significantly improved the molecular weight, T-peel strength, and water resistance of WPUs, suggesting that DETA was an effective crosslinking agent. The WPU dispersions with a 2 : 3 molar ratio of AAS/DETA chain extenders exhibited excellent properties. At a molar ratio of 1.6 for NCO groups to OH groups, a stable WPU dispersion possessed higher solid content of 42.8%. Furthermore, only 4 wt% organic solvents were used in the preparation of WPU dispersions. Results revealed that the obtained WPU dispersions are a potential candidate for binders in water-based inks, without removing organic solvents. This study may provide some insight or guidance for the design and preparation of water-based ink binders.

Facile preparation of homogenous waterborne poly(urethane/acrylate) composites and the correlation between microstructure and improved properties

AbstractHomogenous waterborne polyurethane/polyacrylate emulsions were synthesized based on the prepared polyurethane and polyacrylate through a facile process. The attention was attracted to the miscibility and performance of waterborne polyurethane and polyacrylate. The structures and properties of waterborne polyurethane and waterborne polyurethane/polyacrylate samples were characterized by using Fourier transform infrared spectroscopy, transmission electron microscope, X‐ray photoelectron spectroscopy, X‐ray diffractometer, thermogravimetric, and so forth, as well as solid content and tensile testing. The results showed that the micro morphology of waterborne polyurethane/polyacrylate emulsion presented single‐phase structure with the stoichiometric polyacrylate content increasing from 33% to 80% to waterborne polyurethane. The waterborne polyurethane/polyacrylate films surface is rich in polyacrylate phase. Meanwhile, waterborne polyurethane/polyacrylate composites showed significant improvement in thermal stability and elongation at break, smaller particle size and narrower particle size distribution comparing with waterborne polyurethane.

Reinforcement of Waterborne Polyurethane Films with Poly(acrylic acid)-Modified Palygorskite Fibers

Palygorskite (PAL) is a natural fibrous clay mineral which attracted tremendous attention as reinforcing agent to polymers. In this paper, a facile and environmental friendly modification process of PAL by poly acrylic acid (PAA) via in-situ polymerization in PAL/water gel has been reported. The effects of PAA modified PAL (PAA-PAL) on the mechanical and thermal properties of waterborne polyurethane (WPU) nanocomposites have been investigated. Scanning electron microscopy (SEM) demonstrated that the dispersion of PAL has improved dramatically after PAA modification. Tensile tests showed that PAA-PAL has a significant reinforcement effect on WPU matrix. Addition of 10 wt% PAA-PAL, the tensile strength and the Young’s modulus of WPU composites increased 235 % and 388 %, respectively. Furthermore, the thermal stability of WPU also has been distinctly improved via addition of PAA-PAL.

Investigation of the migration ability of silicone and properties of waterborne polyurethanes

A series of silicone–waterborne polyurethanes (WPU) are prepared by a pre–polymer method based on poly(tetramethylene ether glycol), isophorone diisocyanate, and polydimethylsiloxane (PDMS). The effect of the molecular weight of PDMS and film–forming temperature on the properties of WPU are investigated. The hydrophobicity of the films is characterized by X–ray photoelectron spectroscopy, contact angle and water absorbed measurements. With increasing molecular weight of PDMS in the WPU films, the contact angles increase, surface free energies decrease, and a substantial enrichment of silicon moieties at the film–air interface is observed. As the film–forming temperature increases, more silicone migrates to the film–air interface, which improves the hydrophobicity of the film bulk. The extent of variable phase separation caused by the mobility and incompatibility between silicone and the WPU segment is observed in the matrix of the WPU films by scanning electron microscopy. The degree of phase separation increases with the molecular weight of PDMS and film–forming temperature.

Study of solvent-free sulfonated waterborne polyurethane as an advanced leather finishing material

A solvent-free waterborne polyurethane was synthesized via one-component crosslinking using N-[(2-amionoethyl)-amino] ethane sulphonated sodium as the post-chain extender. The effects of the N-[(2-amionoethyl)-amino] ethane sulphonated sodium and polyol content on the properties of waterborne polyurethane were investigated. The results indicate that at the optimum post-chain extender (6 mol%) and polyol (15.5 mol%) content, the waterborne polyurethane demonstrated best comprehensive properties. A clear advantage of the approach is that, in contrast with the traditional synthesis technique of waterborne polyurethane, the reaction process did not need any organic solvents to reduce the system viscosity. Also, a more natural optical appearance was obtained by the drying process of waterborne polyurethane itself. The as-developed waterborne polyurethane coating can be extensively used on the artificial leather and synthetic leather surfaces.

Preparation and properties of waterborne polyurethane with star-shaped hyperbranched structure

The second-generation hydroxyl-terminated hyperbranched polyester (HB-20) was used as the core, and perfluorooctylethanol (PFOE), monohydroxypolyoxyethylene ether (MPEG) and n-octadecyl alcohol (C18) were grafted to the periphery of HB-20, coupled by isophorone diisocyanate (IPDI) to synthesize four star hyperbranched polymers (SHPs). The structures of the four synthesized typical SHPs were characterized by FT-IR, 1H NMR and 19F NMR. The SHPs obtained were introduced into anionic waterborne polyurethane (WPU) and waterborne polyurethanes (FWPUs) with good storage stability modified by SHPs were prepared. The particle size and morphology of FWPUs were characterized by dynamic laser light scattering and TEM. The surface chemical composition and surface hydrophilic and hydrophobic regions of FWPU film were characterized by XPS and AFM. The surface energy, mechanical properties and thermal properties of FWPU film were determined. The water absorption and moisture permeability of FWPU film were also discussed.

Tailoring the morphology and properties of waterborne polyurethanes by incorporation of acrylic monomers

A series of waterborne polyurethane-acrylate (WPUA) hybrid emulsions in the presence of organic silicon were synthesized by the reaction of isophorone diisocyanate, polytetramethylene ether glycol, double hydroxyl terminated polydimethylsiloxane, methyl methacrylate, and butyl acrylate as mainly raw materials. Three WPUA dispersions with differently internal structures (core-shell, inverse core-shell and semi-interpenetrating network (semi-IPN)) were designed in this study. The morphological analysis was carried out by transmission electron microscopy (TEM) and showed that the designed structures were obtained by changing synthesis method. The mobility of silicon, which affects the water resistance of the films, is determined by the structure of the WPUA and was evaluated by X-ray photoelectron spectroscopy (XPS) and contact angle (CA) measurements. The degree of silicon migration and water resistance were the highest for the WPUA with the semi-IPN structure. The WPUA with the core-shell structure had the highest tensile strength and the best thermal stability. The WPUA with the inverse core-shell structure had the worst mechanical property. Scanning electron microscopy (SEM) results showed that the WPUA with semi-IPN structure had the highest degree of phase separation.

Effects of different macrodiols as soft segments on properties of waterborne polyurethane

Waterborne polyurethane (WPU) with different macromolecular diols as soft segments was synthesized by the acetone dilution method. Fourier transform infrared (FTIR) spectroscopy, particle size and distribution (PSD) and transmission electron microscopy (TEM) test measurements were utilized to characterize the structure. The effect of the structure on performance was determined by the solids content, rheological and thixotropic behavior tests, water absorption tests and adhesion tests. It was found that with different macromolecular diols as a soft segment polyurethane has low water absorption, high energy storage, good shear resistance and adhesion. The minimum water absorption value was 6.02%.

수분산 폴리우레탄 코팅의 미세상분리와 물성에 Isosorbide가 미치는 영향

Series of waterborne polyurethanes (WPUs) containing poly(tetra methylene glycol) (PTMG), 4,4-dicyclohexylmethane diisocyanate (HMDI), 2,2-dimethylolpropionic acid (DMPA), 2,2,4-trimethyl-1,3-pentanediol (TMPD), isosorbide (ISO) and ethylenediamine (EDA) were synthesized. The effects of ISO on the structure and properties of WPUs were studied by gel permeation chromatography (GPC), Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), dynamic mechanical analyzer (DMTA), X-ray diffraction (XRD), thermogravimetry (TG), mechanical test, chemical resistance and hardness test. The deconvolution analysis of FTIR of WPUs revealed that the hydrogen bond interaction in the WPUs increased with the increase of ISO content. Furthermore, the degree of microphase separation was increased with the increase of hydrogen bond interaction, which was confirmed by DSC, XRD and DMTA test. The results demonstrated that the addition of ISO can increase the hydrogen bond interaction between the hard and hard segments in WPUs, which improved the mechanical properties of the WPU films. The highest tensile strength was obtained of 59.67 MPa when the content of isosorbide was 10.35 wt%. Moreover, the ISO was helpful to improve the chemical resistance and hardness of the coatings by the comprehensive performance analysis.

Effect of novel aliphatic fluoro‐diol content on synthesis and properties of waterborne polyurethanes

ABSTRACTThis study synthesized a waterborne polyurethane (WPU) prepolymer by using polytetramethylene glycol, isophorone diisocyanate, and 2,2,3,3,4,4,4‐Heptafluoro‐butynic acid 2,2‐bis‐hydroxymethyl‐butyl ester (HFBA). Subsequently, a series of novel HFBA/WPUs were synthesized by adopting ethylenediamine as the chain extender. The results from Fourier transform infrared spectroscopy demonstrated that the CO groups of HFBA/WPUs shifted to lower wavenumbers as the HFBA content increased. Moreover, when the HFBA content of the synthesized HFBA/WPUs increased, the WPU initial decomposition temperature, glass transition temperature, tensile strength, and Young's modulus also increased. Furthermore, the results of atomic force microscopy identified a relatively high number of humpy protrusions and roughness levels in the HFBA/WPUs with a relatively high HFBA content, causing higher hydrophobicity of these HFBA/WPUs. Furthermore, in vitro platelet and erythrocyte adhesion experiments revealed that increasing the HFBA content lowered platelet and erythrocyte adhesion on the surface of the WPUs. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47356.

Self‐healing waterborne polyurethane coating by pH‐dependent triggered‐release mechanism

ABSTRACTIn this study, effect of high‐loaded silica capsules with corrosion inhibitor on thermal degradation and self‐healing properties of waterborne polyurethane (WPU) was investigated. Silica capsules were synthesized using an oil in water (O/W) microemulsion and WPU was prepared via the prepolymer method. Assembled capsules demonstrated pH dependent release of their core. Incorporating silica capsule as an inorganic component resulted to improve thermal and barrier properties of WPU coatings. WPU coating with 1% silica capsules demonstrated better barrier quality in corrosive media and adding more than that resulted a rapid deterioration in barrier properties. Furthermore, such coatings possess an excellent adhesive strength with steel substrate. Electrochemical impedance spectroscopy was used in corrosion monitoring and healing procedure. Moreover, capsule morphology and thermal degradation of the WPU coating has been investigated separately by scanning electron microscopy and thermal gravimetric analysis. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47082.

Properties of Waterborne Polyurethane Filled with Fluorinated Polyphosphazene Microspheres In Situ Polymerization

Properties of Waterborne Polyurethane Filled with Fluorinated Polyphosphazene Microspheres<i> In Situ</i> Polymerization

Solvent-free and self-catalysis synthesis and properties of waterborne polyurethane

A carboxy modified long-chain diol (CMLCD) was synthesized for the first time through esterification of pyromellitic dianhydride (PMDA) and polytetramethylene glycol 1000 (PTMG1000). Waterborne polyurethane (WPU) was prepared based on an organic solvent-free and self-catalytic process, using synthesized CMLCD as a hydrophilic diol. The CMLCD has self-catalytic ability to the reaction of hydroxyl and isocyanate during the prepolymerization, which can greatly shorten the preparation period and avoid the utilization of highly toxic catalyst such as dibutyltin dilaurate. Importantly, the prepared WPU has narrow particle size distribution with the average particle size of 137 nm, which leads to good stability even centrifugated at 3000 rpm. Mechanical test results show that the WPU film possesses good mechanical performance with the tensile strength of 59.3 MPa and elongation at break of 819.2%. Additionally, the prepared WPU film has high water resistance. This study is attractive for future green WPU in industrial production and application.

캐슈넛 껍질 오일(CNSL) 기반 바이오 폴리올을 이용한 수분산 폴리우레탄 박막의 기계적 물성 향상

캐슈넛 껍질 오일(CNSL) 기반 바이오 폴리올을 이용한 수분산 폴리우레탄 박막의 기계적 물성 향상

Study on the Application Properties of WPU and OMMT in RTV Mold Rubber

The purpose of this work was to research on the application properties of waterborne polyurethane (WPU) and organic montmorillonite (OMMT) in room-temperature-vulcanizated silicone rubber (RTV) used as mold materials. The first part dealt with the application of WPU in RTV matrix. The composite with 3% WPU showed the highest tensile strength and elongation at break, 4.1 MPa and 1441%, respectively. These properties were improved about 28% and 55% compared with that pure RTV. The COLE and COVE of RTV/WPU-3 was 0.2×10−4∼1.2×10−4K−1 and 2.7×10−3∼4.4×10−3K−1, respectively. These values were lower compared with that of pure RTV. The second part dealt with the application of OMMT in RTV/WPU composites. When 3% OMMT was added, the tensile strength and elongation at break were increased to 5.6 MPa and 1534%, respectively. The COLE and COVE of RTV/WPU-3/OMMT-7 was 0.32×10−4∼0.94×10−4 K−1 and 0.32×10−3∼2.3×10−3K−1. These values showed an obvious decrease compared with that of RTV/WPU-3 composite. After the addition of 3% OMMT, the acid and alkali resistance of these composites were improved. X-ray diffraction (XRD) and scanning electron microscope (SEM) were also used in the investigation of the microtopography of these RTV composites.

Effects of trimethylol propane and AAS salt on properties of waterborne polyurethane with low gloss

Abstract A series of waterborne polyurethane(WPU) dispersions containing different amounts of trimethylol propane(TMP) and/or 2-[(2-aminoethyl)amino]ethanesulfonic acid sodium salt (AAS salt), were synthesized by prepolymer emulsification process. The effects of TMP and AAS salt on properties of WPU dispersions were discussed to find out the appropriate formulation of WPU dispersion with low gloss. The results showed the particle size of WPU increased as the TMP content increased, but a decrease to the gloss and transparency. Spherical granules emerged in the surface morphology of WPU films when the TMP content exceeded beyond 1% by weight via scanning electron microscope (SEM). In contrast, as the AAS salt content increased, the particle size of WPU decreased, and the gloss and transparency increased. It was most worth noting that the dispersion stability of WPU dispersions was enhanced dramatically with the increase of AAS salt content by measuring the Zeta potential of emulsion. Therefore, WPU dispersions with low gloss and high dispersion stability can be prepared successfully with the AAS content of 0.5% by weight and the TMP content of 1%–1.5% by weight when other influence factors were fixed to a suitable condition.

Erratum to: The Effect of Improved Crosslink Density on the Properties of Waterborne Polyurethanes Using Sol-Gel Process

Erratum to: The Effect of Improved Crosslink Density on the Properties of Waterborne Polyurethanes Using Sol-Gel Process

Synthesis and investigation of well-defined silane terminated and segmented waterborne hybrid polyurethanes

The properties of waterborne polyurethanes were improved significantly by incorporating silane both in the backbone and side chains.