Polyurethane Dispersions Research Articles

Bio‐based waterborne polyurethane structural color films with high stability

AbstractIn recent years, structural colors derived from photonic crystals (PCs) with a periodically ordered nanostructure are gorgeous and iridescent, but once their structure is destroyed, they will fade. In this work, the feasibility of the application of bio‐based waterborne polyurethanes (WPU) in structural color films was explored. The structural stability of PCs is enhanced bio‐based WPU as a kind of green product, which can replace solvent polyurethane one. A tung oil polyol (TOP) is fabricated by one‐step method with simple purification process and used to prepare waterborne polyurethane dispersions (WPUD). More introduction of TOP into the WPUD may help improve tensile strength and hydrophobic capability. It shows excellent mechanical properties with 16.8 MPa in tensile strength and water contact angle 109.5°. The SEM images confirmed that bio‐based WPU is more conducive to the self‐assembly of silica particles than traditional WPU.

Analysis of Paint Properties According to Expandable Graphite and Fire Simulation Research on Firewall Penetration Part.

In this research, we attempted to develop paints that can be applied to various fields such as high-rise building structures and electric vehicle batteries. To minimize damage to life and property in the event of a fire, we attempted to manufacture a highly elastic paint material that can block flames and control smoke spread, and that has additional sound insulation and waterproofing functions. A high-elasticity paint was manufactured by mixing a flame-retardant polyurethane dispersion (PUD) with an acrylic emulsion binder and adding different mass fractions of expandable graphite (EG). The thermal, physical, and morphological properties of the prepared mixed paint were analyzed. The thermal properties of the mixed paint were analyzed and intended to be used as input data (heat transfer coefficient, specific heat capacity) for fire simulation. Output data were used to predict how much the temperature would change depending on the time of fire occurrence. The reason for conducting simulations on the fire stability of paint materials is that the fire stability of paints can be predicted without conducting fire tests. Two hours after the fire broke out, the thermal temperature distribution was analyzed. The temperature distribution was compared with and without mixed paint. Two hours after a fire broke out in a virtual space, it was found that when the mixed paint was applied, the surrounding temperature of the penetration area was lower than when the mixed paint was not applied. Development costs for developing excellent paints can be reduced. Since fire safety can be predicted without actually conducting tests, the time required for product development can be reduced. We are confident that this is a very groundbreaking technology because it allows fire safety simulations for developed products to be conducted in a virtual space by creating an environment similar to actual fire test standards.

The Post-Curing of Waterborne Polyurethane-Acrylate Composite Latex with the Dynamic Disulfide-Bearing Crosslinking Agent.

The development of a dynamic network for commodity polymer systems via feasible methods has been explored in the context of a society-wide focus on the environment and sustainability. Herein, we demonstrate an adaptive post-curing method used to build a self-healable network of waterborne polyurethane-acrylate (WPUA) composite latex. The composite latex was synthesized via the miniemulsion polymerization of acrylates in the dispersion of waterborne polyurethane (PU), with commercial acetoacetoxyethyl methacrylate (AAEM) serving as the functional monomer. Then, a dynamic disulfide (S-S)-bearing diamine was applied as the crosslinking agent for the post-curing of the hybrid latex via keto-amine condensation, which occurred during the evaporation of water for film formation. It was revealed that the microphase separation in the hybrid films was suppressed by the post-curing network. The mechanical performance exhibited a high reliability as regards the contents of the crosslinking agents. The reversible exchange of S-S bonds meant that the film displayed associative covalent-adaptive networks in the range of medium temperature in stress relaxation tests, and ≥95% recovery in both the stress and the strain was achieved after the cut-off films were self-healed at 70 °C for 2 h. The rebuilding of the network was also illustrated by the >80% recovery in the elongation at break of the films after three crushing-hot pressing cycles. These findings offer valuable insights, not only endowing the traditional WPUA with self-healing and reprocessing properties, but broadening the field of study of dynamic networks to polymer hybrid latex.

Novel enrichment in biobased monomers of waterborne polyurethane dispersions as a textile finishing agent for poly-cotton fabrics

This study introduces a novel biobased textile finishing agent synthesized as waterborne polyurethane dispersions (FCCB-WPUDs), utilizing bio-based monomers like fenugreek oil-based polyol, corn oil-derived emulsifier, and cellulose acetate butyrate (CAB) chain extender. The FCCB-WPUDs were prepared through the prepolymer polymerization method and characterized using FTIR, TGA, DMA, SEM, DLS, and swelling tests. Their application to poly-cotton fabrics significantly improved various fabric properties. The enhancements included increased washing fastness (from 3/4 ± 0.01 to 4 ± 0.02 for dyed and 3 ± 0.02 to 4/5 ± 0.02 for printed fabrics), rubbing fastness (from 3 ± 0.02 to 4/5 ± 0.03 for dyed and 4 ± 0.02 to 4/5 ± 0.03 for printed fabrics), and perspiration fastness (from 3 ± 0.02 to 4 ± 0.03 for acidic dyed and 3/4 ± 0.02 to 4 ± 0.02 for alkaline printed fabrics). Additionally, tear strengths improved significantly (from 13.66 ± 0.04 N/m to 20.53 ± 0.06 N/m for warp dyed and 10.85 ± 0.06 N/m to 15.14 ± 0.06 N/m for warp printed fabrics), along with tensile strengths (from 327 ± 5.38 N/m to 361 ± 3.26 N/m for warp dyed and 357 ± 5.34 N/m to 449 ± 4.90 N/m for warp printed fabrics). These improvements correlated with increasing CAB moles as a chain extender. This research presents a cost-effective and simple biobased method for textile finishing, offering an alternative to petrochemical-based monomers in conventional WPUD preparation.

Bio-based non-isocyanate polyurethane(urea) waterborne dispersions for water resistant textile coatings

Currently, the resins used in industrial polyurethane coatings are made from petro-based polyols and isocyanate building blocks. In traditional coating formulations, polyurethane resins can be solubilized in solvents for their application on substrates, thus releasing possibly volatile organic compounds (VOCs) upon drying. To circumvent these issues, polyurethanes synthesized from non-isocyanate and bio-based building blocks are receiving more interest. However, only few references describe the development of waterborne non-isocyanate dispersions with a direct application.In this study, non-isocyanate polyurethane(urea)s of very high bio-based contents (>80 wt%) and having controlled amount of reactive hydroxyl ends were synthesized via transcarbamoylation. The obtained resins were used as cationic waterborne dispersions in a sustainable coating system. The influence of the functionality and hydrophobicity of the neutralization agent used to protonate the non-isocyanate polyurethane(urea) backbones, as well as the dicarbamate monomer structures were assessed. It was found that the combination of monofunctional and hydrophilic dl-lactic acid neutralization agent (for electrostatic repulsion) led to stable dispersions with better properties (particle size and zeta potential) than the commercial waterborne polyurethane dispersion reference. Those dispersions were cross-linked through their reactive hydroxyl end groups with tetramethylol acetylene diurea into freestanding films and adhesive layers for textile coatings. The freestanding films exhibited high cross-linking efficiency (gel content >90 %), low water uptake (down to 2 %) and high water and methyl ethyl ketone (MEK) resistance (≥200 rubs) as well as good mechanical properties (Young's modulus between 1.5 MPa and 3.1 MPa and elongation at break up to 300 %) to resist the deformation of the fabrics when applied on them. Finally, when used as an adhesive layer on textiles, good resistance to hydrolysis and heat aging were ensured by the coating system, thus potentially replacing isocyanate based adhesive layers.

New dispersions for pigment printing binders in the manufacture of light industry goods

Pigment printing using screen technology has certain problems associated with the limited use of domestic raw materials. The expansion of the range of printing inks fills the need for small-circulation production of textile products with original artistic and color design and the use of modern printing equipment. In this work, the possibility of using new aqueous polyurethane dispersions as binders in pigment printing was explored for the first time. This will expand the range of thickeners through the use of polyurethane dispersions, ensuring the production of strong and elastic polymer films during low-temperature processing. Such dispersions are environmentally friendly products, since toxic solvents are not used. We propose the application of new polyurethane thickeners in compositions with polyurethane dispersions as a rheological modifier. The rheological parameters of printed compositions and the physical and mechanical properties of films of polyurethane dispersions were determined and it was found that the dispersions used are capable of forming a soft and plastic film. This confirms the suitability of these film-forming preparations for use in pigment printing. The new binders based on polyurethane dispersions make possible to create effective printing compositions, to improve the quality of prints and to impart improved performance properties.

Puncture Resistance and UV aging of Nanoparticle-Loaded Waterborne Polyurethane-Coated Polyester Textiles.

The goal of this research was to investigate the effect of different types of nanoparticles on the UV weathering resistance of polyurethane (PU) treatment in polyester-based fabrics. In this regard, zinc oxide nanoparticles (ZnO), hydrophilic silica nanoparticles (SiO2 (200)), hydrophobic silica nanoparticles (SiO2 (R812)), and carbon nanotubes (CNT) were mixed into a waterborne polyurethane dispersion and impregnated into textile samples. The puncturing resistance of the developed specimens was examined before and after UV-accelerated aging. The changes in chemical structure and surface appearance in nanoparticle-containing systems and after UV treatments were documented using microscopic pictures and infrared spectroscopy (in attenuated total reflectance mode). Polyurethane impregnation significantly enhanced the puncturing strength of the neat fabric and reduced the textile's ability to be deformed. However, after UV aging, mechanical performance was reduced both in the neat and PU-impregnated specimens. After UV treatment, the average puncture strength of all nanoparticle-containing systems was always greater than that of aged fabrics impregnated with PU alone. In all cases, infrared spectroscopy revealed some slight differences in the absorbance intensity of characteristic peaks for polyurethane polymer in specimens before and after UV rays, which could be related to probable degradation effects.

Synthesis and characterization of waterborne polyurethane-based ink binder modified via a silane coupling agent

The development of high-performance waterborne polyurethane ink binder presents challenges due to the lack of outstanding water resistance, adhesion, and heat resistance in traditional waterborne polyurethane. Herein, series of waterborne polyurethane emulsions were synthesized using the pre-polymerization chain expansion and self-emulsification method, with varying contents of 3-aminopropyl triethoxysilane as the modified post-chain extender. The effect of varying the concentration of 3-aminopropyl triethoxysilane on the characteristics of waterborne polyurethane dispersions and films was investigated. The results indicated that there was a significant improvement in adhesion, thermal stability, and water resistance with an increase in the concentration of 3-aminopropyl triethoxysilane. Specifically, When the introduction amount was 3 wt%, the resulting film exhibited the best overall properties, including a tensile strength of 48.4 MPa, water absorption of 4.3 wt%, shear strength and adhesion of 3.9 MPa and 3.86 MPa respectively, as well as a T-peel strength of 14.9 N/mm. This work provided meaningful guidance for developing a novel waterborne polyurethane-based ink binder with strong adhesion, high mechanical properties, and excellent water resistance.

Preparation and characterization of high solid content cationic waterborne polyurethane with core‐shell structures

AbstractIn this study, core‐shell structured cationic waterborne polyurethane (WPU) dispersions with high solid content were prepared. To this end, prepolymer A was synthesized from polytetramethylene ether glycol (PTMG), isophorone diisocyanate (IPDI), castor oil (CO) and 1,4‐butanediol (BDO) without integration of the hydrophilic groups. Prepolymer B with hydrophilic groups was prepared from PTMG, IPDI, CO, BDO and N‐methyldiethanol amine (MDEA). WPU dispersion with a core‐shell structure could be generated by mixing, neutralizing, and emulsifying of the prepolymer A and the prepolymer B. The results indicated that the generation of WPU dispersions through this technique exhibited a milky appearance while the pH values range from 5.30 to 5.60. The optimal combination of prepolymer A and prepolymer B (at a ratio of 5:5) resulted in a dispersion with the highest solid content (50.4%), lowest viscosity (69 mPa·s), and narrowest particle size distribution. As the proportion of prepolymer A to prepolymer B decreases, the tensile strength of WPU film reduces while the elongation at break and glass transition temperature increases. Moreover, initially the contact angle with water was decreased instead of increase. However, modifications in a ratio of prepolymer A and B was not showed any significant impact on the thermal stability performance of the WPU films.

Sustainable Strategies for Synthesizing Lignin-Incorporated Bio-Based Waterborne Polyurethane with Tunable Characteristics.

In this study, we introduce a novel approach for synthesizing lignin-incorporated castor-oil-based cationic waterborne polyurethane (CWPU-LX), diverging significantly from conventional waterborne polyurethane dispersion synthesis methods. Our innovative method efficiently reduces the required solvent quantity for CWPU-LX synthesis to approximately 50% of that employed in traditional WBPU experimental procedures. By incorporating lignin into the polyurethane matrix using this efficient and reduced-solvent method, CWPU-LX demonstrates enhanced properties, rendering it a promising material for diverse applications. Dynamic interactions between lignin and polyurethane molecules contribute to improved mechanical properties, enhanced thermal stability, and increased solvent resistance. Dynamic interactions between lignin and polyurethane molecules contribute to improved tensile strength, up to 250% compared to CWPU samples. Furthermore, the inclusion of lignin enhanced thermal stability, showcasing a 4.6% increase in thermal decomposition temperature compared to conventional samples and increased solvent resistance to ethanol. Moreover, CWPU-LX exhibits desirable characteristics such as protection against ultraviolet light and antibacterial properties. These unique properties can be attributed to the presence of the polyphenolic group and the three-dimensional structure of lignin, further highlighting the versatility and potential of this material in various application domains. The integration of lignin, a renewable and abundant resource, into CWPU-LX exemplifies the commitment to environmentally conscious practices and underscores the significance of greener materials in achieving a more sustainable future.

STUDY OF THE ANTISTATIC PROPERTIES OF MATERIALS TREATED WITH COLLOIDAL COMPOSITIONS BASED ON METAL NANOPARTICLES

The article provides a short overview of the application of metal nanoparticles in the textile indus- try, describes their properties and application`s fields. The definitions of electrification, electrostatic field, electric charge density are given. The application of processing of fabrics by polyurethane dispersion and metal nanoparticles in technological processes of textile materials finishing is justified. The objects of the study are cotton fabric`s samples with addition of synthetic fibres, colloidal solutions of silver and copper nanoparticles, aqueous polyurethane dispersion. The antistatic properties of the fabrics have been studied. The electrostatic field intensity of the samples was measured on the device ST-01, with the density of the electric charge calculating according to the intensity values. It has been experimentally established, that the processing of fabrics by solutions of nanoparticles of metals contributes to reduction of intensity of their electrostatic field to 65 %, compared with the initial samples. It is noted that treatment of fabrics by polyure- thane dispersion in combination with copper nanoparticles gives no clear antistatic properties to the blended fabrics.

Waterborne polyurethane dispersions based on polypropylene glycol/polycarbonate diol: Evaluation of their use as wood protective coatings

AbstractWhen exposed to the open air, the wood can change its physical and structural properties due to the combined effect of ultraviolet radiation, oxygen, humidity, atmospheric pollutants, and microorganisms. The demand for durable coatings with application to wooden structures or pieces is always a relevant topic. Waterborne polyurethane (WPU) dispersions as wood protective coatings might be attractive, especially outdoors. In this work, WPU dispersions have been synthesized from isophorone diisocyanate and different ratios of polypropylene glycol and polycarbonate (PC) diol. Synthesized polyurethanes were applied to wood surfaces as a coating. The results showed that the partial and total replacement of polypropylene glycol (PPG) by PC influences the mechanical, thermal, and structural properties of the films obtained from aqueous polyurethane dispersions. In addition, a simple and promising methodology based on Fourier‐transform infrared (FTIR) spectra was proposed to determine the polycarbonate content in poly(carbonate‐ether‐urethane). The synthesized coatings reduced water absorption by the wood, especially the one with a 25:75 polycarbonate to PPG ratio. The applied coating does not impact the final color of the wood, allowing a natural aging effect. Polyurethanes are promising for use as coatings for wood.

Synthesis and application of flame retardant self‐matting aqueous polyurethane dispersion

AbstractTo address the issues of insufficient film smoothness, and flammability of aqueous polyurethane dispersions (PUD) prepared by adding matting agents, two hydrophilic chain extenders, dimethylolpropionic acid (DMPA) and sodium 2‐[(2‐aminoethyl)amino] ethanesulphonate (A95), were used to regulate the particle size of the emulsion while using FRC‐6 flame retardant as a small molecule chain extender to prepare a self‐matting and flame retardant PUD. Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscope, and atomic force microscopy were used to structurally characterize the latex films. The results showed that as theR‐value (NCO/OH molar ratio) and soft segment content decreased, the prepolymer viscosity increased, making it difficult to emulsify and reducing the glossiness of the film. Moreover, an initial increase in DMPA content led to a decrease in film glossiness, followed by an increase. Increasing the molar ratio of A95 sulfonic acid salt‐based chain extender to EDA affected the glossiness of the film, with a 2:8 molar ratio of A95: ethylenediamine (EDA) resulting in a glossiness of the film of 6.5%. The addition of reactive flame retardant diethyl bis (2‐hydroxyethyl) aminomethyl phosphonate (FRC‐6) increased the branching content in the prepolymer, improved the flame retardancy of the film, and reduced its glossiness. As a result, the self‐prepared PUD had a flat film with a glossiness as low as 6.0% and a flame retardancy rating of level 4.

Development of biocompatible aqueous polyurethane dispersions using chitosan and curcumin to improve physicochemical properties of textile surfaces

The present research work aims to synthesize a blend of chitosan (CSN) and curcumin (CRN) based aqueous polyurethane dispersions (CSN-CRN APUDs) for the modification of textile surfaces. A series of anionic CSN-CRN APUDs were prepared by the reaction of isophorone diisocyanate (IPDI) with polyethylene glycol (PEG) and extended with chain extenders (CSN and CRN). Structural characterizations of prepared materials were examined through a fourier transformed infrared (FTIR) spectrophotometer. The performances of coated CSN-CRN APUDs on the colorfastness properties (washing, rubbing and perspiration) and the mechanical properties like tensile strength and tearing strength of plain weaved poly/cellulosic textiles (dyed, printed and white) were examined before and after the application of CSN-CRN APUDs. The findings showed that the mechanical and colorfastness properties of all the CSN-CRN APUDs treated poly/cellulosic textile samples were improved significantly as compared with untreated poly/cellulosic textile samples. The newly synthesized CSN-CRN APUD coating materials are sustainable and greener products, particularly derivatized from bio-resources. These coating materials can be utilized as outstanding eco-friendly substitutes for poly/cellulosic textile coatings for surface modifications.

Emulsion homopolymerization of chlorotrifluoroethylene toward new waterborne fluorocarbon coatings

To solve the problems of environmental unfriendliness brought by long fluoroalkyl chain surfactant used in the homopolymerization of chlorotrifluoroethylene (CTFE) monomers as well as film forming difficulty and poor adhesion of PCTFE resins at the same time, a short fluoroalkyl capping waterborne polyurethane (F-WPU) dispersion was firstly synthesized in this work based on the processes of self-emulsification and phase inversion. The prepared fluorinated polyurethane dispersions could reduce the surface tension of water to 17.81–19.04 mN/m, showing high surface activity. Subsequently, the PCTFE (Poly(chlorotrifluoroethylene)/F-WPU composite latex was successfully prepared by emulsion homopolymerization, of which the F-WPU was used as the stabilizer and microreactor of system to emulsify CTFE monomers and then the corresponding composite coatings were further fabricated. Effects of the type and addition amount of F-WPU on emulsion homopolymerization of CTFE and the stability of composite emulsion were systematically studied. As a result, the PCTFE/F-WPU composite latex exhibits excellent wetting ability on various low surface energy substrates, and the composite coating displayed excellent adhesion and UV (Ultraviolet) resistance due to the synergistic action of F-WPU and PCTFE. The synthesis of F-WPU not only opens up a new route for the preparation of fluorinated surfactants, but also provides a new method for the emulsion homopolymerization of fluoroethylene monomers, and accelerates the wide application of fluorocarbon latex coating.

Recyclable Thin-Film Soft Electronics for Smart Packaging and E-Skins.

Despite advances in soft, sticker-like electronics, few efforts have dealt with the challenge of electronic waste. Here, this is addressed by introducing an eco-friendly conductive ink for thin-film circuitry composed of silver flakes and a water-based polyurethane dispersion. This ink uniquely combines high electrical conductivity (1.6×105 S m-1 ), high resolution digital printability, robust adhesion for microchip integration, mechanical resilience, and recyclability. Recycling is achieved with an ecologically-friendly processing method to decompose the circuits into constituent elements and recover the conductive ink with a decrease of only 2.4% in conductivity. Moreover, adding liquid metal enables stretchability of up to 200% strain, although this introduces the need for more complex recycling steps. Finally, on-skin electrophysiological monitoring biostickers along with a recyclable smart package with integrated sensors for monitoring safe storage of perishable foods are demonstrated.

Biodegradable waterborne polyurethane‐urea dispersion adhesives with high biocontent

AbstractNon‐biodegradable petroleum‐based plastic wastes have become a leading environmental concern, and new efforts are underway to prepare biobased and biodegradable replacements. We have explored the preparation of adhesives suitable for use in consumer products, and here we report the development of waterborne, biodegradable adhesives from biobased monomers resulting in adhesives exceeding 70% biocontent. Using water as the polymer medium, viscosity challenges and the use of volatile organic solvents are avoided. Material properties of the polyurethane dispersions, resulting films, and laminates produced showed Mw ranging between 56,000 and 124,000. Lastly, the biodegradability of films and laminates was evaluated. The resulting metrics indicate that the adhesives produced meet the desired mechanical and biodegradability targets, indicating that high renewability content solvent‐free polyurethane dispersions are a viable solution for lamination adhesives.

Іnfluence of finishing on the material performances

The complex of polyacrylic and polyurethane films physical and mechanical properties and the operational properties of leather decorated with them has been studied. The polyacrylate and polyurethane protective coatings formation is performed on the grain face of the semi-finished leather. 
 150–200 µm thick films are formed from the polymer solutions and aqueous dispersions. Acrylic films are obtained from a dispersion of methylbutylacrylate and a dispersion modified by acrylic lcarboxyethanolamine of kerosene-gas-oil fraction natural naphthenic acids. Polyurethane films are formed by the method of condensation structure formation in the presence of water vapor based on 4,4’-diphenylmethanediisocyanate, polyethylene glycol and polyester. Polyacrylurethane films are obtained from an aqueous dispersion of polyurethane and acrylate Lepton SPC.
 The coating is applied to the semi-finished leather by watering and spraying the polymer composition. The complex of physical-mechanical and sorption-diffusion properties of polymer films has been studied. It was found that the films obtained from the polyacrylurethane composition outperform polyurethane and polyacrylic by 1.9 and 6.7 times, respectively. Modification of the polyurethane composition with a polyacrylic polymer makes it possible to obtain films with higher sorption-diffusion properties.
 Polyurethane coated leather is superior to polyacrylic in the complex of physical and mechanical parameters, in particular in terms of adhesive strength in 3.4-4.4 times, and polyacrylurethane coated leather - in 5 times. Such leather has the highest sorbino-diffusion capacity, which is 1.4 times higher in vapor permeability compared to skins with polyacrylic coating. The acrylurethane polymer-based composition is promising formation of eco-coatings based on them in the technology of manufacturing leather materials. The studied polymeric film formers can be used for the formation of various kind protective coatings on a wide range of semi-finished leather products.

High solid and low viscosity waterborne polyurethane acrylate with excellent anti-corrosion and anti-bacterial performances

The design and preparation of great corrosion resistance and high-solid waterborne polyurethane dispersion with low viscosity is still a challenge in the field of the polyurethane industry. Herein, we developed a simple method involving a core-shell process to prepare a core-shell structured waterborne polyurethane acrylate dispersion (WPUAD). First, isobornyl acrylate, a derivative of natural product borneol, dihydroxylated by a thiol-ene click reaction was used to prepare oil-based polyurethane acrylate as prepolymer A (core) and waterborne polyurethane acrylate as prepolymer B (shell). Then, the core-shell WPUAD was obtained by mixing and emulsifying the two prepolymer at a certain ratio. The study reveals that the core-shell structured WPUAD not only has a low viscosity (~1330 mPa.s) but also holds a high-solid content (~ 60 wt%). At the same time, the highly solid WPUAD has excellent stability with no breast breakage even after more than 1 year of storage. In addition, various electrochemical measurements, water contact angles, and water absorption tests were performed to determine the anti-corrosive properties of the WPUAD-derived coatings. The results show that the WPUA coatings exhibit significantly enhanced anticorrosion with respect to the single prepolymer B derived coatings, which is attributed to their high cross-linking density resulting from the core-shell structure and the introduction of hydrophobic isobornyl acrylate. In addition, because of the introduction of the dihydroxylated isobornyl acrylate as chain extenders, the WPUA coating has great anti-bacterial adhesion properties with an anti-bacterial efficiency of 82.3 %. We believe that our work provides a generic preparation method to obtain a commercially available high-solid WPUAD with excellent anti-corrosion properties.

Preparation of strong adhesive waterborne coating on polyester fabric based on cation-π interaction and its application in oil/water separation

Polyethylene terephthalate (PET) is widely used in industry and daily life with its excellent mechanical and thermodynamic properties, and its surface property arising from coating has a great impact on its application. However, most coatings on PET display poor fastness and environmental pollution because of inactive surface and organic solvent. Encouraged by the cation-π interaction between the cationic and aromatic groups, we designed a strong adhesive waterborne polyurethane (PU) coating on PET fabric for oil/water separation. The bis(2-hydroxyethyl) dimethylammonium chloride (BDAC) in polymer not only provides PU with self-emulsification property, but also endows the coating with strong cation-π interaction with PET substrate. The effect of hydrophilic group on the property of PU dispersion was investigated by adjusting the content of BDAC. In addition, the interaction of optimized PU dispersion with single PET fiber was also quantitatively studied by adhesion force and surface tension measurements. It was demonstrated that the introduction of BDAC as cationic group resulted in a strong adhesion of PU coating on PET fabric and the coating could withstand various harsh environments. Furthermore, the synthesized coating could be used as an intermediate adhesive layer to anchor fumed SiO2 on PET fabric, improving the surface roughness and hydrophobicity of the substrate. The modified fabric exhibited remarkable durability and excellent ability for oil/water separation.