Waterborne Polymer Research Articles

A surfactant-mediated dynamic protection strategy for 100% waterborne fabrication of durable superhydrophobic coatings

Waterborne preparation of superhydrophobic coatings now becomes strongly favored because of its environmental and health friendliness. However, the huge surface energy difference between low surface-energy components and water still poses a challenge for achieving their co-dispersion. Here, a surfactant-mediated protection strategy is proposed to achieve well dispersion of both SiO2 nanoparticles and perfluorosilane in water as well as block their conjugation, thereby fabricating a 100% waterborne F-FC-SiO2 suspension with high homogeneity and dispersion stability. During the painting and drying process, demulsification spontaneously triggers the deprotection and enables sufficient covalent conjugation between perfluorosilane and SiO2, thus achieving a superhydrophobic coating. This supramolecular protection/deprotection approach enables high compatibility of the F-FC-SiO2 suspension with versatile waterborne polymer emulsions (e.g., waterborne polyurethane, waterborne polysiloxane, and waterborne epoxy resin) to fabricate durable superhydrophobic coatings. The resulting composite coating can impart super-repellency to various substrates against aqueous solutions and multiple oils, displaying high antifouling and self-cleaning properties, as well as resistance to extreme mechanical abrasion and weathering. This work provides a promising approach for the convenient production of totally waterborne superhydrophobic coatings.

Preparation and properties of fluorinated VAc-VeoVa10 latex emulsified with allyl nonyl phenoxy propyl alcohol polyoxyethylene ether ammonium sulphate

Purpose The traditional VeoVa10-VAc copolymer latex, which prepared via the emulsion polymerization of the mixed monomers of VAc and VeoVa10, has the poor water resistance and thermal stability because of the migration of the conventional emulsifier molecules and the low bond energy of C-C bond. The purpose of this work is that the fluorinated monomer is used to modify the latex. The film of the resultant latex has the C-F bond with high bond energy and low surface energy, which can effectively improve the heat resistance and water resistance of the resultant film. In addition, the reactive emulsifier is used to replace the conventional emulsifier. The drawbacks of the conventional emulsifier molecules migrate and desorb can be avoided when the polymer latex is stored, thereby also improving the water resistance. Design/methodology/approach The modified VAc-VeoVa10 latex has been successfully synthesized via the semi-continuous seeded emulsion polymerization, which VAc and VeoVa10 is used as the main monomers and HFMA was used as the functional monomer. KPS and reactive surfactants of SE-10 were used as the initiator and emulsifier, respectively. The structure of resultant latex film was characterized by Fourier transform infrared spectroscopy (FTIR). The latex films were tested by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and contact angle (CA). The particle size and its distribution of the latex were measured by the nano particle size analyzer. Findings The factors that had an influence on the properties of the latex and the film were investigated in detail. The stability of the resultant latex is good. The average particles of the latex and its distribution are small and uniform, respectively. In comparison with the conventional latex film, the thermal stability and hydrophobicity of the resultant latex film are improved obviously. Practical implications The resultant latex can be used in both the waterborne interior and exterior wall coatings, pickering stabilized waterborne polymer dispersions, polymer powders, environmentally friendly polymer-modified waterproof mortar and other fields, which can be satisfied with the high demand of thermal stability and hydrophobicity. Originality/value The modification of poly (VAc-VeoVa10) by reactive surfactant and fluorinated monomer is seldom reported. In this study, the fluorinated poly (VAC-VeoVa) latex is prepared via the reactive surfactants, which VAc and VeoVa10 is used as the main monomers and hexafluorobutyl methacrylate is used as the functional monomer. Potassium persulfate (KPS) and allyl nonyl phenoxy propyl alcohol polyoxyethylene ether ammonium sulfate are used as the initiator and emulsifier, respectively.

Overcoming Challenges of Incorporation of Biobased Dibutyl Itaconate in (Meth)acrylic Waterborne Polymers.

Polymeric derivatives of itaconic acid are gaining interest as biobased alternatives to petroleum-based monomers due to their versatility, renewable nature, commercial availability, and cost-effectiveness. Itaconate ester monomer's challenges incorporating in (meth)acrylic waterborne polymers are the low propagation rate, unfavorable reactivity ratios, and the depropagation process. To overcome these challenges, the seeded semibatch emulsion polymerization of 100% biobased dibutyl itaconate, methyl methacrylate, and butyl acrylate was investigated at different temperatures. Consequently, 30 wt % DBI was successfully incorporated within waterborne (meth)acrylates in short reaction times (4 h), obtaining high DBI incorporation (>90%). The results demonstrate that DBI incorporation influences the instantaneous monomer conversion, polymer's microstructure, and mechanical properties. By incorporating a biobased itaconate cross-linker, kinetics and mechanical characteristics of the polymers were improved. This combined approach can be implemented without altering industrial processes, resolving the commercialization dilemma for itaconate monomers to synthesize high-performance biobased polymers for adhesive and coating industries.

Emulsion copolymerization of 2-methylene-1,3-dioxepane (MDO) and acrylate monomers: Incorporation vs hydrolysis

The incorporation of polyester moieties to the backbone of waterborne polymer dispersions by the emulsion copolymerization of 2-methylene-1,3-dioxepane (MDO) and acrylate monomers (n-butyl acrylate and 2-octyl acrylate) is explored in this work. Due to the competition between the consumption of MDO by hydrolysis (MDO is very sensitive to water) and by copolymerization reactions, seeded semibatch emulsion copolymerizations were carried out varying the temperature of the reaction, the feeding rates of the comonomers, and maintaining a basic pH (∼pH = 8) that decreases notably the rate of hydrolysis of the MDO. Interestingly, we found that the lower the temperature of the reaction (T = 20 °C) and the higher the monomer addition flow rate, allowed the highest incorporation of MDO in the copolymer (up to 86 mol %). Unfortunately, the MDO incorporated in the closed formed (i.e., in the acetal form) and therefore, the acrylate copolymers produced did not contain ester groups in the backbone. Furthermore, increasing the MDO composition in the copolymers under the same polymerization conditions favored more hydrolysis than copolymerization and hence, incorporation content decreased. On the other hand, the ester size (2-octyl vs n-butyl) of the acrylate did not have any noticeable effect in the MDO incorporation content.

The hidden secrets of the average number of radicals per particle ([formula omitted]) and their implications in control of emulsion polymerization reactors

Emulsion polymerization is the method of choice to produce waterborne polymers but is susceptible to run-to-run variations. This variability is hard to avoid because on-line measurement of many of the characteristics of interest, in particular the molar mass distribution (MMD) of non-linear polymers, is not possible. This work offers a way to solve this problem. First, it is shown that the average number of radicals per particle (n¯), a value that can easily be obtained from kinetic measurements, contains sufficient information to directly determine the distribution of particles with n radicals. It is then demonstrated that for a given measured MMD, knowledge of the distribution of radicals per particle allows solving the long standing problem of the accurate estimation of the effective termination rate coefficient in emulsion polymerization. Combining this knowledge, it is shown the value of n¯ alone (a value that can be obtained experimentally by calorimetric measurements) can be used to develop a soft sensor able to estimate on-line the molar mass distribution of highly non-linear polymers. This, for the first time, offers the possibility of on-line control of the MMD of non-linear emulsion polymers.

A Review of Waterborne Polymer–Cementitious Composite Repair Materials for Application in Saline Soil Environments: Properties and Progress

The properties of a large number of concrete infrastructures in China are deteriorating year by year, raising the need for repairing and strengthening these infrastructures. By introducing waterborne polymers into a cement concrete system, brittle cracks and easy bonding performance defects of concrete can be compensated for to form a long-life, semi rigid, waterborne polymer-modified cementitious repair material with a promising development prospect. This paper investigates the modification effect of polymer emulsions on ordinary cement mortar. Our research mainly focused on the physical and mechanical properties, durability, microstructure and application status of waterborne polymer-modified cementitious composites. Literature studies show that with the increase in waterborne polymer content (0 wt%~20 wt%), the performance of cement mortar significantly improves, which in turn expands its application range. Compared with ordinary cement mortar, the introduction of waterborne polymers blocks some of the pores in the cement to a certain extent, thus improving its permeability, freeze–thaw resistance and durability. Finally, this paper describes the application of waterborne polymer–cementitious composites in western saline soil environments, as well as discusses the prospects of their development.

Self-healing and antistatic waterborne polyurethane hybrid coating resulting from hard but reversible Zr-O-Si networks

Robust, self-healing waterborne coatings have become the preferred choice in the field of flexible electronic devices owing to their outstanding compliance, restorability, and environmental friendliness. Nevertheless, most of the existing self-healing waterborne polymers exhibit viscoelasticity, irreversible fatigue damage, and the challenge of reconciling self-healing functions with mechanical properties, all stemming from inherent molecular structure contradictions between flexibility and rigidity. Here, we propose a novel strategy that utilizes a nanofiller with dynamic reversible bonds to overcome the self-healing limitations that theoretically demand flexible chain, for achieving both mechanical robustness and self-healing ability in the waterborne polyurethane (WPU) hybrid coating system. We modified tetrapropyl zirconate (TPOZ) with 3-aminopropyltriethoxysilane (APTES) to enhance compatibility between the matrix and inorganic particles, while the formation of dynamic reversible bonds through both condensation hydrolysis endows the self-healing abilities. The WPU hybrid coating was designed by covalently incorporating amino-modified TPOZ (A-ZrO2) into a glycinamide-functionalized WPU network, conferring excellent fracture energy (50.3 kJ/m2), elastic recovery, along with antistatic capability to the coating. Furthermore, the hybrid coating maintains a robust mechanical performance alongside 92.58 % of healing efficiency, exhibiting a potential for flexible electronics application. The hybridization strategy via incorporation of the nanofillers with hard but reversible covalent bond resolves the inherent robustness-healing trade-off, providing exciting thoughts to expand WPU applications.

Zwitterionic stabilized water-borne polymer colloids for antifouling coatings

This study presents antifouling waterborne (meth)acrylic coatings prepared through seeded semi-continuous emulsion polymerization, using trace amounts of a zwitterionic monomer 2-(methacryloyloxy)ethyl dimethyl-(3-sulfopropyl)ammonium hydroxide (DMAPS). DMAPS was introduced with a dual purpose, to establish a protective layer of DMAPS containing polymer chains on the films' surface, thereby imparting antifouling characteristics, while simultaneously provides in-situ colloidal stability to the emulsion during polymerization.By providing colloidal stability to (meth)acrylic polymer particles in aqueous dispersion (latex), DMAPS-rich units are distributed on the surface of the polymer particles and subsequently on the surface of the resulting polymer films. Subsequent analysis revealed that the films exhibited diminished hydrophilicity, a more textured surface, and diminished affinity for water entrapment compared to conventionally stabilized (meth)acrylic films. Such surfaces demonstrated high resistance to fouling and weak adhesion of the studied BSA protein. These effects were positively influenced by the quantity of DMAPS incorporated within the (meth)acrylic films that allow higher coverage with DMAPS rich polymer chains.The proposed methodology not only emphasizes a potent pathway for the development of environmentally-conscious, waterborne film-forming coating technology but also involves the simultaneous integration of a zwitterionic surface layer, conveying remarkable antifouling attributes to the resulting (meth)acrylic coating film.

Waterborne polymers and coatings from bio-based butenolides.

In the quest for sustainable paints and coatings, bio-based resources for the polymeric binder constituents are key. Recently, we introduced poly-butenolides as bio-based acrylate replacement for solventborne and 100% solids (UV-curing) coatings. Here, we report the first step towards aqueous poly-butenolide dispersions, enabling the use of this novel binder technology platform in waterborne coatings.

Progress in waterborne polymer dispersions for coating applications: commercialized systems and new trends

Modern polymer coatings are shifting away from dispersion in volatile organic solvents towards waterborne, minimizing harmful environmental emissions.

Waterborne Polymer Coatings with Bright Noniridescent Structural Colors.

Structural color pigments offer an efficient, sustainable, and environmentally friendly approach to obtain waterborne polymer coatings. We developed polymer-based spherical photonic pigments to incorporate in aqueous dispersions of polymer nanoparticles used to obtain waterborne polymer films. Our spherical photonic pigments are assembled from polymer nanoparticles and are highly stable in water dispersion, maintaining their optical properties in the final polymer films. Unlike conventional dyes and pigments, which are prone to photobleaching because they are based on the absorption of light, photonic pigments rely on the selective reflection of light by their nanostructure and therefore are not photodegraded. Furthermore, different colors can be obtained from the same materials, changing only their nanostructure, in this case, the size of the polymer nanoparticles. Our novel spherical photonic pigments are noniridescent and can be incorporated in aqueous polymer nanoparticle dispersions without deteriorating their structure to produce waterborne polymer coatings with structural color. This approach for structural colored waterborne polymer coatings is efficient, simple, and environmentally friendly, offering excellent prospects for application in paints and coatings.

Internally reinforced soft core-hard shell waterborne dispersions for high performance crack and solvent free coatings

Waterborne polymer dispersions composed of soft core-hard shell particles allows obtaining mechanically robust coatings that can be cast at low temperatures without the use of coalescent agents. However, the presence of a hard phase at the outer shell of the particle increases the stress generated during film formation leading to cracks. The need of forming films free of cracks limits the mechanical properties of the coating. This article explores a strategy of enhancing the mechanical properties of waterborne coatings without compromising the film formation properties of soft core-hard “shell” polymer particles. The approach is based on a multiphase internal core composed by hard and soft domains. This strategy resulted in coatings with higher Young's modulus, stress at break and toughness, without compromising the film formation characteristics.

Oxygen evolution from extremophilic cyanobacteria confined in hard biocoatings.

Biocoatings, in which viable bacteria are immobilized within a waterborne polymer coating for a wide range of potential applications, have garnered greater interest in recent years. In bioreactors, biocoatings can be ready-to-use alternatives for carbon capture or biofuel production that could be reused multiple times. Here, we have immobilized cyanobacteria in mechanically hard biocoatings, which were deposited from polymer colloids in water (i.e., latex). The biocoatings are formed upon heating to 37°C and fully dried before rehydrating. The viability and oxygen evolution of three cyanobacterial species within the biocoatings were compared. Synechococcus sp. PCC 7002 was non-viable inside the biocoatings immediately after drying, whereas Synechocystis sp. PCC 6803 survived the coating formation, as shown by an adenosine triphosphate (ATP) assay. Synechocystis sp. PCC 6803 consumed oxygen (by cell respiration) for up to 5 days, but was unable to perform photosynthesis, as indicated by a lack of oxygen evolution. However, Chroococcidiopsis cubana PCC 7433, a strain of desiccation-resistant extremophilic cyanobacteria, survived and performed photosynthesis and carbon capture within the biocoating, with specific rates of oxygen evolution up to 0.4 g of oxygen/g of biomass per day. Continuous measurements of dissolved oxygen were carried out over a month and showed no sign of decreasing activity. Extremophilic cyanobacteria are viable in a variety of environments, making them ideal candidates for use in biocoatings and other biotechnology. IMPORTANCE As water has become a precious resource, there is a growing need for less water-intensive use of microorganisms, while avoiding desiccation stress. Mechanically robust, ready-to-use biocoatings or "living paints" (a type of artificial biofilm consisting of a synthetic matrix containing functional bacteria) represent a novel way to address these issues. Here, we describe the revolutionary, first-ever use of an extremophilic cyanobacterium (Chroococcidiopsis cubana PCC 7433) in biocoatings, which were able to produce high levels of oxygen and carbon capture for at least 1 month despite complete desiccation and subsequent rehydration. Beyond culturing viable bacteria with reduced water resources, this pioneering use of extremophiles in biocoatings could be further developed for a variety of applications, including carbon capture, wastewater treatment and biofuel production.

Preparation and Utilization of a Comb‐Like Polycarboxylate Dispersant for Organic Pigment

AbstractAs a novel form of carboxylate comb‐like copolymers, SAM‐(m)PEG was prepared by polymerizing styrene (S), acrylic (A), and maleic anhydride (M) to obtain a random copolymer labeled SAM. SAM was then esterified using either polyethylene glycol (PEG) or methyl PEG (mPEG), a waterborne polymer dispersant for dispersing and stabilizing C.I. Pigment Yellow 180 (PY 180). The structures of SAM‐(m)PEG and the ground suspension of PY 180 were characterized by Fourier transform infrared (FT‐IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, scanning electron microscopy (SEM), a nanoparticle size analysis, and viscometry. The effects of different branch chains, synthetic formulas, and grinding conditions on the dispersibility of SAM‐(m)PEG were evaluated. In addition, the optical properties of the pigments were investigated after ultrafine grinding. The adsorption mechanism between the SAM‐(m)PEG dispersants and PY 180 particles is also discussed. SAM‐PEG6002 outperformed the other SAM‐(m)PEG dispersants owing to its excellent dispersion and stability. When used as the dispersant, the average particle size (Z‐average) of PY 180 after grinding was 264.6 nm, and the particle size distribution became narrow (PDI=0.089). Moreover, SAM‐PEG6002 effectively maintained the color performance of the pigment, and the product was successfully applied to the pigment coating. Therefore, SAM‐PEG6002 is an effective waterborne polymer dispersant for organic pigments.

Prospects for Application of Guanidine-Containing Organomineral Complexes as Biocidal Functional Additives for Waterborne Polymer Materials

Prospects for Application of Guanidine-Containing Organomineral Complexes as Biocidal Functional Additives for Waterborne Polymer Materials

Prospects for Application of Guanidine-Containing Organomineral Complexes as Biocidal Functional Additives for Waterborne Polymer Materials

The possibility of using organomineral complexes of polyhexamethylene guanidine hydrochloride as a functional additive for a waterborne paint based on polyvinyl acetate has been investigated. Organomineral complexes containing 20 and 30 wt % guanidine polymer have been obtained, with intercalation of polyguanidine chains into the interlayer space of montmorillonite being observed. It has been revealed that the stability of the polymer film to water is retained when organomineral complexes are introduced into a polyvinyl acetate dispersion, whereas the water resistance of the film sharply decreases when free polyguanidine is added. There was no significant influence of organomineral complexes on the rheological characteristics of the dispersion and its sedimentation stability. Testing of waterborne paints with various additives has shown that introduction of organomineral complexes into the material prevents the coating from fouling by biofilms of gram-positive bacteria Staphylococcus aureus and Rhodococcus erythropolis, with the hardness, water resistance, and water-vapor transmission of the coatings being retained at a satisfactory level.

Waterborne polymer composites containing hybrid graphene/carbon nanotube filler: Effect of graphene type on properties and performance

AbstractPolymer composites based on graphene/carbon nanotubes (G/CNT) and reduced graphene oxide/carbon nanotubes (rGO/CNT) were synthetized by in‐situ miniemulsion polymerization containing 1 wt% hybrid filler with different ratio of G and CNT (10:1, 1.1, 1:10). From the hybrid aqueous dispersions obtained in that way polymer films were spontaneously formed at ambient conditions by water evaporation. The effect of the type of the graphene filler, G or rGO, on the properties and performance of polymer composites was studied. It was shown that G/CNT based composites presented improved morphology of the film due to better distribution of the filler and more organized structure of the film than that of rGO/CNT composites. The surface of the film was much smoother indicating more deepen filler within the polymer. Consequently, the G/CNT/polymer composites presented one order of magnitude increased Young's moduli and 60% lower water uptake than the neat polymer. Even though rGO/CNT/polymer composites presented also improved mechanical resistance, their water resistance was compromised probably due to the presence of hydrophilic functional groups that facilitated the water diffusion within the film.

Morphological and rheological investigation of emulsified asphalt/polymer composite based on gray-level co-occurrence matrix

Emulsified asphalt/polymer is one of the most applied composite materials in pavement industry, which is also defined as emulsified polymer modified asphalt (PMA). PMA exhibits the transition behavior of multi-physical states with corresponding viscoelastic characteristics, and studies had focused on the application performances of PMA. However, few had paid proper attention to the morphological compatibility of PMA, which dominated its viscoelastic transition and failure probability directly. This paper aims to establish a gray-level co-occurrence matrix (GLCM) model with morphology theory to quantitatively describe the morphological compatibility of PMA, combined with fluorescent microscope. Furthermore, waterborne polymers with self-crosslinking characteristics are introduced to modify emulsified asphalt, including acrylate, epoxy resin, polyurethane and liquid rubber. The rheological characteristics of PMA are comprehensively evaluated through performance grade, steady shear viscosity, and master curve tests. Finally, a statistical analysis is conducted to establish the relationship between morphological compatibility and rheological characteristics of PMA. The approach introduced in this study could be a promising method to investigate the multi-physical transition behaviors and morphological compatibility of emulsified asphalt/polymer composite material.

Click reaction benzimidazole into waterborne polyurethane toward anti-flashing rust, self-healing, robust coatings

Waterborne coatings have emerged as a promising alternative to traditional solvent-based coatings due to their environmentally friendly and easy application characteristics. Nevertheless, the application of these coatings is still limited by significant challenges such as the occurrence of flash rust phenomenon and the difficulty of reconciling mechanical properties with self-healing functions. Here, we report a novel self-healing waterborne polyurethane coating that utilizes coordination chemistry to achieve anti-flashing rust, mechanical robustness, and preserve self-healing and adhesion capabilities. The waterborne coating was designed by attaching 2-(2-benzimidazolyl) ethanethiol (BET) onto the polyurethane side chain. The conjugated benzimidazole forms a coordination structure with the tinplate substrate, effectively preventing the occurrence of flashing rust from the metal substrate during the film-forming process. Furthermore, BET forms a Zn(II)-ligands cross-linking structure with the exogenous zinc ions through coordination bonds, resulting in a distinctive sparse inside and dense outside structure due to the inhomogeneous distribution of zinc ions within the coating, thereby leading to high surface hardness (4H), and holding strong adhesion (∼2.0 MPa). In addition, the coordination between Zn2+ and BET provides extra interchain forces, resulting in a high self-healing efficiency (95.9%). Our work proposes a novel strategy to address the contradiction of simultaneously achieving anti-flashing rust and high hardness, without compromising adhesion and self-healing capabilities, thus offering the potential for expanding the commercial applications of waterborne polymer coatings.

Anticorrosive waterborne polyurethane coating with Gemini surfactant‐assisted exfoliation of hexagonal boron nitride nanosheets

AbstractThe uniform dispersion of hexagonal boron nitride (h‐BN) in a waterborne polymer matrix remains a challenge in preparing waterborne uniform h‐BN/polymer composite coating. Here, cationic Gemini surfactant (GS‐16) is used as a surfactant and intercalator to exfoliate and functionalize bulk h‐BN for preparing GS‐16‐functionalized h‐BN nanosheets (G‐BNNS). For comparison, the conventional hexadecyl trimethyl ammonium bromide (CTAB) surfactant with the same structural unit was utilized to prepare CTAB‐functionalized BNNS (C‐BNNS). Compared with C‐BNNS, G‐BNNS exhibits larger lateral size, lower thickness, and larger specific surface area. G‐BNNS and C‐BNNS are subsequently blended with waterborne polyurethane (WPU) to prepare composite coatings. Their morphologies, surface roughness, water resistance, mechanical properties and anticorrosive performance of composite coatings are comparatively studied. The water resistance, mechanical, and thermal stability of G‐BNNS/WPU‐0.3 wt% composite films are higher than that of C‐BNNS/WPU‐0.3 wt% and WPU films. The impedance modulus of G‐BNNS/WPU‐0.3 wt% is four orders of magnitude higher than that of pristine WPU and at least one order of magnitude higher than C‐BNNS/WPU‐0.3 wt%. GS‐16 is demonstrated to be an effective surfactant and intercalator to exfoliate and functionalize h‐BN. The as‐prepared G‐BNNS is also certified to be a high‐performance anticorrosive filler for waterborne polymer‐based coatings.