Waterborne Emulsion Research Articles

Synthesis of Water-Dispersible Poly(dimethylsiloxane) and Its Potential Application in the Paper Coating Industry as an Alternative for PFAS-Coated Paper and Single-Use Plastics.

Polyethylene-, polyvinylidene chloride-, and per- and polyfluoroalkyl substance-coated paper generate microplastics or fluorochemicals in the environment. Here, we report an approach for the development of oil-resistant papers using an environmentally friendly, fluorine-free, water-dispersible poly(dimethylsiloxane) (PDMS) coating on kraft paper. Carboxylic-functionalized PDMS (PDMS-COOH) was synthesized and subsequently neutralized with ammonium bicarbonate to obtain a waterborne emulsion, which was then coated onto kraft paper. The water resistance of the coated paper was determined via Cobb60 measurements. The Cobb60 value was reduced to 2.70 ± 0.14 g/m2 as compared to 87.6 ± 5.1 g/m2 for uncoated paper, suggesting a remarkable improvement in water resistance. Similarly, oil resistance was found to be 12/12 on the kit test scale versus 0/12 for uncoated paper. In addition, the coated paper retained 70-90% of its inherent mechanical properties, and more importantly, the coated paper was recycled via pulp recovery using a standard protocol with a 91.1% yield.

Correction to “Epoxy soybean oil plasticized vinyl chloride acrylate waterborne emulsion: Physically mixed versus chemically grafted”

Correction to “Epoxy soybean oil plasticized vinyl chloride acrylate waterborne emulsion: Physically mixed versus chemically grafted”

Epoxy soybean oil plasticized vinyl chloride acrylate waterborne emulsion: Physically mixed versus chemically grafted

AbstractIn this study, two types of epoxy soybean oil (ESO) modified vinyl chloride acrylate copolymer emulsion (vc‐m), that is, physically modified vc‐m‐1 and chemically grafted vc‐m‐2, were well prepared initially. The chemical structure, particle size distribution, surface morphology, flexibility, and mechanical properties of the three emulsions were studied through Fourier transform infrared analysis, proton nuclear magnetic resonance analysis, nano‐size analysis, atomic force microscopy, dynamic mechanical analysis, as well as tensile test. Compared with vc‐m, the glass transition temperature (Tg) of vc‐m‐1 and vc‐m‐2 was reduced by nearly 28%, the tensile strength was increased by 50%, and the elongation at break was improved by 70.5% and 70.7%, respectively. No significant difference was identified between vc‐m‐1 and vc‐m‐2. Furthermore, the chemical reaction mechanism and internal plasticizing mechanism of vc‐m‐2 synthesis were discussed. ESO enhanced the low‐temperature brittleness and mechanical strength of the emulsion, and vc‐m‐2 exhibited better migration stability while maintaining the identical flexibility and mechanical properties as vc‐m‐1. The modified emulsion is capable of adapting to low ambient temperatures when applied to coatings and road adhesives while showing promising applications.

Synthesis and characterization of water-borne vanillin derived copolymers containing dynamic imine cross-links

In the effort toward the production of circular plastics, the use of lignin-derived aromatic building blocks such as vanillin is interesting due to their functionality. Nonetheless, the water-borne emulsion polymerization of acrylic monomers derived from vanillin is still lacking. Vanillin can be readily functionalized with a methacrylate group for the radical polymerization to yield polymers containing functional aldehyde side groups. The functionality can be exploited via imine formation to produce vitrimers, a class of cross-linked recyclable polymers. Besides recycling, synthesis via a water-borne emulsion polymerization is desired to reduce the negative contribution of solvents on the environment and health. In the present work, polymethacrylates based on 2-(methacryloyloxy)ethyl vanillin and 2-octyl acrylate were synthesized via a emulsion polymerization approach to produce a water-borne latex. A latex with a small particle size (49 nm) and solid content of 31 wt% was obtained. For comparative purposes, a similar polymer was synthesized via solution polymerization. Both polymers were cross-linked using a multifunctional amine to produce recyclable imine vitrimers. This research investigates the unique combination of water-borne synthesis and vitrimer polymers, and therefore contributes to future development of vitrimer latex products such as coatings and films.

Stabilisation of acrylic latexes containing silica nanoparticles for dirt repellent coating applications

This study examines the feasibility of using colloidal silica nanoparticles as active agents in high concentration waterborne polymer latex formulations. We showed that distributing the silica throughout the waterborne emulsion formed a composite coating material with a hydrophilic surface that consequently reduced exterior dirt pickup. Two grades of silica nanoparticles were studied, one using sodium stabilisation and another using epoxysilane modification to introduce glycidoxypropyltrimethoxysilane surface functionality. Rheological study of the waterborne latex on mixing showed that there was an immediate pH responsive interaction between the silica sols and the polymer latex. Once loading of sodium charge stabilised silica NPs exceeded the volume required for heteroflocculation to occur the mixture demonstrated the potential to gel on standing – a process which took weeks, or months, to occur depending on the pH and relative concentrations used. At least fifty percent silane modification to the NP surface was found to be necessary to maintain a stable colloidal dispersion for long term storage of the waterborne latex. Despite this both grades of silica were found to imbue reductions in dirt pickup when applied to exterior masonry concrete studies over a 3-month weathering test.

Electrostatic-modulated interfacial crosslinking and waterborne emulsion coating toward waterproof, breathable, and antifouling fibrous membranes

Developing hydrophobic surfaces for flexible fibrous membranes has attracted tremendous attention for their potential applications in waterproofing, antifouling, and drag reduction. However, conventional methods, such as hydrothermal, coating, and phase separation, often involve complex preparation processes,plugging of porous structures,and heavy use of organic solvents. Herein, a facile and eco-friendly assembly strategy is proposed for fabricating superior hydrophobic surfaces on fibrous membranes. Firstly, a hierarchical rough structure was created on the fiber surface using titanium dioxide nanoparticles as building blocks by a one-pot procedure based on electrostatic complexation and interfacial crosslinking. The procedure is performed in aqueousmedia, at low temperature (50℃) and very fast (∼20 min). Subsequently, a waterborne emulsion was developed by low-surface-energy organosilicon self-assembly in aqueousmedia, which was adopted to coat fiber substrate for surface hydrophobization. The amount of organosilicon is reduced by >90 % of that required in the traditional coating. Consequently, the resultant fibrous membranes exhibit a robust hydrophobic surface with UV-resistant,washdurability, photocatalytic self-cleaning effect, and excellent breathable properties. Besides, this general waterborne hydrophobic coating strategy could be applied to various hydrophilic substrates, including fabrics, aerogels, and sponges. This work provides a novel method to design and fabricate multi-functional hydrophobic surfaces.

Fabrication of bulk hydrophobic cement-based materials with ultra-high impermeability

The internal hydrophobic modification of cement-based material will undoubtedly significantly improve its durability, which is of great significance for prolonging its service life in harsh environments such as the ocean. In this study, a bulk hydrophobic cement-based materials were fabricated mainly based on polydimethylsiloxane (PDMS) and nano-silica (SiO2) as the main components of the composite emulsion. The research results demonstrate that waterborne emulsion of PDMS@SiO2 can be uniformly dispersed and effectively used in cement-based materials. The hydroxyl groups of hydrophobic emulsions can combine with the hydroxyl groups from the hydration surfaces of cement minerals to form hydrogen bonds, which result in mortars with bulk hydrophobicity. In developed cement-based materials, water contact angle can reach an overhydrophobic state with 132°. For developed compositions, the water repellent properties and corrosion resistance have been significantly improved.

Understanding and Improving the Oil and Water Barrier Performance of a Waterborne Coating on Paperboard.

Using paperboard as packaging material is more sustainable than using plastic. To be a viable replacement, however, the barrier properties of paperboard need to be improved. Applying a waterborne barrier coating for both oil and water is an attractive method to improve the barrier performance of paperboard food packaging. However, not much is known about the oil and water barrier properties and penetration pathways of such coatings. Here, an alkali-soluble resin (ASR)-stabilized waterborne emulsion polymer was prepared and applied on untreated paperboard. Its performance as oil and water barrier coating was investigated, and the penetration pathways for both oil and water through the coating are discussed. The presence of surface defects in the coating applied on the paperboard strongly affects both the oil and water barrier properties, but the coating’s morphology and chemical nature only play a major role in the water barrier performance. The optimal barrier performance for oil and water was achieved when adding 5 wt % isopropanol (IPA) to the dispersion and applying two coating layers on paperboard. The IPA improves film formation and reduces the number of surface defects, which is explained by a more favorable spreading coefficient of the coating over the paperboard substrate. These insights will help to improve the oil and water barrier properties of polymer-coated paperboard for more sustainable packaging applications.

Effects of Selected Pigments on the Properties of Silicone Resin-Based Paints.

The purpose of this research was to evaluate the impact of selected pigments on the performance of waterborne emulsion paint. Each pigment was incorporated into the paint at 5% w/w. Density and viscosity measurements as well as the rub-out test were used to test the wet state properties of the colored paint. Wet-scrub, adhesion-to-substrate, water-uptake, vapor-permeability, UV-aging, and other tests were conducted to evaluate effects of the pigments on the dried paint. Bohemian green earth pigment was found to have the most positive effect, as it improved the water resistance of the paint without changing its rheological properties. Therefore, this pigment was selected for further studies, in which the pigment was included as part of the paint formula rather than as a post-additive. The results were satisfactory, confirming the compatibility of the pigment with the formula. However, a slight change in the rheological profile of the paint was observed during tests on a rotational rheometer. This research shows the need for intensive quality control measures while testing alternative formulations, to both enable early detection of negative effects and identify possible improvements.

Mechanical Performance of Single-Graded Copolymer-Modified Pervious Concrete in a Corrosive Environment.

Polymer-modified cement has found numerous applications due to its excellent tensile strength. When cement was modified with a single polymer, its tensile strength and performance marginally increased. However, when a small amount of the flexible polymer latex was added to cement, the mechanical performance of cement considerably improved. In this study, single-graded copolymer-modified pervious concrete was prepared by mixing styrene-butadiene rubber (SBR) with different acrylate polymers, and its mechanical performance and durability were systematically studied through mechanical tests and theoretical analyses. The main findings are as follows: (1) When a waterborne emulsion was added, the freeze resistance of cement concrete increased, and its mass loss rate decreased. Cement concrete with two latexes had higher sulphate corrosion resistance and substantially lower dry shrinkage strain than ordinary cement concrete. (2) Through scanning electron microscopy, the microstructural changes in the cement binder, ordinary polymer-modified concrete, and the copolymer-modified cement concrete used in this study were observed, and the findings were compared with those reported in the literature. (3) Single-graded copolymer-modified pervious concrete exhibited excellent shrinkage performance. This study showed that single-graded copolymer-modified pervious concrete satisfied the performance requirements for use as a paving material for special cases.

Computational simulation a system of waterborne polyurethane matrix by β-C induction with ZnO and CaCO3 particles

This work includes the search for the development of a composite of a WPU (waterborne polyurethane), β-CD (β-Cyclodextrin), PZnO (zinc oxide particles), and the presence of CaCO3, to obtain new properties such as adhesion to multiple substrates of organic and inorganic origin. Therefore, a development sequence was proposed: Computational development: conformation of the polymeric matrix (with the intermediary polymers) and simulation of the interaction between β-CD and PZnO and Ca+2 and CO3-2 ions, as well as insertions in β-CD, computational simulations were carried out with the help of ACD LABS™ (free version) software and by molecular dynamics with GROMACS™. With the above, we were able to determine properties such as interfacial tensions, surface tensions, and contact angles, and degrees of solvation and stability in waterborne emulsions. Therefore, it is important to point out that one of the main contributions of this research proposal is that there are no studies that combine these materials.

Soap-free styrene-acrylic/carbon nanotubes composite latex by in situ emulsion polymerization: Preparation, properties and characterizations

Thermoplastic conductive composites, namely, soap-free styrene–acrylic emulsion (S-A)/carbon nanotubes (CNTs) modified with carboxyl (–COOH) groups, were successfully synthesized by an in-situ semi-continuous seed emulsion pre-emulsification polymerization with allyloxy decyl polyoxyethylene ether (10) (KL) as a reactive emulsifier. The fracture surface scanning electron microscopy (SEM) images of the films illustrated that CNTs are inlayed in the S-A matrix and shaped into a conductive network for electron transport. Compared with neat S-A, the performance of the composites was greatly improved. The curing temperature of the composite emulsion with 4 wt% CNT–COOH was dropped by 16.4 °C. The electrical conductivity of the latex film was improved by eight orders of magnitude. The tensile strength and Young's modulus of the film were boosted by 483% and 2475%, respectively. Additionally, water resistance was ameliorated. These enhancements confirmed that the addition of CNTs can strengthen the curing, heatproof, mechanical, electrical, and waterproof properties of the S-A, which provides a new strategy for the modification of waterborne emulsion.

Preparation of 1, 3, 6, 8-Pyrenesulfonic Acid Tetrasodium Salt Dye-Doped Silica Nanoparticles and Their Application in Water-Based Anti-Counterfeit Ink.

In order to improve the luminescent stability of water-based anti-counterfeit ink, a new fluorescent material is prepared by doping dye into silica nanoparticles. Water soluble anionic dye 1, 3, 6, 8-pyrenesulfonic acid sodium salt (PTSA) is selected as the dopant. In this work, PTSA is successfully trapped into silica nanoparticles (SiNPs) by the reverse microemulsion method using cationic polyelectrolyte poly (dimethyl diallyl ammonium chloride; PDADMAC) as a bridge. The UV absorption spectra, fluorescence emission spectra and fluorescent decay curves are used to describe the luminescent properties of the PTSA-doped silica nanoparticles (PTSA-SiNPs). In addition, the as-prepared PTSA-SiNPs and polyurethane waterborne emulsion are used to prepare water-based anti-counterfeit ink, and fluorescent patterns are successfully printed through screen-printing. The samples printed by the ink exhibit desirable fluorescence properties, heat stability, robust photostability, and a fluorescent anti-counterfeit effect, which makes the PTSA-SiNPs promising luminescent materials for anti-counterfeit applications.

Effect of Urea-Formaldehyde (UF) with Waterborne Emulsion Microcapsules on Properties of Waterborne Acrylic Coatings Based on Coating Process for American Lime

The purpose of this paper is to explore the effect of urea-formaldehyde (UF) with waterborne emulsion microcapsules on the optical, mechanical and aging resistance properties of waterborne coatings from the perspective of coating process. In this paper, the microcapsules were prepared with UF resin as the wall materials and waterborne emulsion as the core materials. Based on the coating process, the optical, mechanical and aging resistance properties of the waterborne acrylic coatings with microcapsules for American lime were tested. The good coating process is three layers of primer, two layers of topcoat, and adding microcapsules into primer. The results showed that the coating process had little effect on the color difference of the paint film with microcapsules, the gloss of the paint film prepared by the good coating process was basically not changed, and the mechanical properties of the paint film were good. At this time, the hardness grade of the paint film was 3H, the adhesion was grade 0, the impact resistance was 110.0 N·cm−2, and the elongation at break was 29.7%. The microcapsules added to the primer had better liquid resistance than those added to the topcoat. The paint film had good stability and aging resistance, and could inhibit the generation of microcracks to a certain extent. The paint film prepared by the good coating process had better comprehensive performance. This work provides a technical reference for self-healing of the waterborne coatings on American lime.

Effect of Modified Hexagonal Boron Nitride Nanoparticles on the Emulsion Stability, Viscosity and Electrochemical Behavior of Nanostructured Acrylic Coatings for the Corrosion Protection of AISI 304 Stainless Steel

In this study, the effect of pure and modified hexagonal boron nitride (h-BN) nanosheet incorporation on the stability, viscosity, and electrochemical behavior of a waterborne emulsion acrylic coating was studied. The functionalization of h-BN nanoplatelets with polyacrylic acid (PAA) plasma polymerization was performed, and the successful surface modification was determined through water dispersion testing, Fourier transform infrared spectroscopy and thermogravimetric analysis, X-ray photoelectron spectroscopy, and also by transmission electronic microscopy. Later, the stability and viscosity properties of emulsion nanostructured acrylic coatings, which were previously prepared by an ultrasound-assisted mixing system, were analyzed using zeta potential and rheometry testing, respectively. The electrochemical behavior was analyzed by electrochemical impedance spectroscopy. The results prove an effective deposition of PAA films on the h-BN surfaces, which enhanced the stability and viscosity acrylic of nanostructured coatings due to the interactions between the h-BN nanoplatelets surface and emulsion acrylic paint and also with the thickener additives. On the other hand, the electrochemical analysis demonstrated a significant increase (two orders of magnitude) in corrosion resistance in the acrylic nanostructured coatings with 1 wt.% of unmodified and modified h-BN nanoplatelets concerning pure acrylic paint due to a barrier protection mechanism of corrosion inhibition. Therefore, the results demonstrate that the surface modification of h-BN by plasma polymerization (green technology) helped to solve the low dispersibility issue of BN nanosheet surfaces in a waterborne polymer matrix to obtained green nanostructured acrylic coatings with the right balance in in-can properties and corrosion inhibition of AISI 304 stainless steel.

Self-stratification of amphiphilic Janus particles at coating surfaces

Durable hydrophobic coatings are created by adding amphiphilic Janus particles to binder polymers through the unique self-stratification behaviours, which offer a novel and cost-effective solution to challenges in waterborne emulsion coatings.

Smart Polyacrylate Emulsion Based on a New ABC-Type Triblock Copolymer via RAFT-Mediated Surfactant-Free Miniemulsion Polymerization: Its Multifunctional Properties.

The present investigation deals with the development of an acrylic-based polymeric emulsion that offers multifunctional properties such as superhydrophobic, antimicrobial, anti-icing, and self-cleaning. The said multifunctional waterborne emulsion was prepared via a surfactant-free reversible addition-fragmentation chain transfer (RAFT) polymerization technique. To accomplish this, a new class of ABC-type triblock copolymer (PMTAC-b-PBA-b-PIBA) based on 2-(methacryloyloxy) ethyl ammonium chloride (MTAC), n-butyl acrylate, and isobornyl acrylate (IBA) was synthesized via a polymerization-induced self-assembly technique in a surfactant-free miniemulsion process. The cationic polymer PMTAC was used as a macro-RAFT agent to prepare the rest of the blocks in the presence of nanosize monodisperse colloidal silica particles, leading to a raspberry-like morphology via ionic interaction between anionic silica particles and the cationic block copolymer (BCP). A water contact angle of more than 150° was achieved for the emulsion coating after the fluorosilane treatment which delineates its superhydrophobic nature. The prepared emulsion showed antimicrobial property both in Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The resultant BCP emulsion was coated over different substrates like glass, paper, and cotton, and the coating material showed anti-icing and self-cleaning properties.

Comb-like polysiloxanes with oligo(oxyethylene) and sulfonate groups in side chains for solvent-free dimethoxysilyl-terminated polypropylene oxide waterborne emulsions

The paper provided a new nonionic-anionic silicone surfactant—comb-like polysiloxanes with oligo(oxyethylene) and sulfonate groups (ESPS) in side chains, which was synthesized by successive hydrosilylation of poly(dimethylhydro)siloxane with allyl poly(ethylene glycol) acetic ester (M n = 540) and allyl glycidyl ether, then ring-opening reaction of oxirane groups with sodium bisulfite. 1H NMR, FT-IR, and gel permeation chromatography (GPC) were used to confirm the chemical structure of the surfactant. The thermal transition behavior of ESPS studied with differential scanning calorimetry (DSC) analysis showed that the surfactant had low glass-transition temperature of − 59.3 °C. Surface tension measurement result indicated that the the surface tension at the critical micelle concentration (cmc, 69.8 mg L−1) was 29.4 mN m−1, which was much lower than those of conventional hydrocarbon surfactants, indicating the higher surface activity of ESPS. The solvent-free dimethoxysilyl-terminated polypropylene oxide waterborne emulsions were prepared using ESPS as the single emulsifier via phase-inversion emulsification technique. An obvious abrupt changing point appearing at the conductivity curves indicated that the phase inversion was completely accomplished. The emulsions prepared with about 3.0 wt% ESPS content in oil phase exhibited excellent storage stability at 50 °C for 42 days and freeze-thaw stability.

Coating based on the modified chlorinated polypropylene emulsion for promoting printability of biaxially oriented polypropylene film

In this paper, a polymeric coating based on the modified chlorinated polypropylene (CPP) emulsion was synthesized, methyl methacrylate (MMA), butyl acrylate (BA) and acrylic acid (AA) were grafted onto CPP backbone and phase inversion was conducted to obtain waterborne emulsion. Results showed that the concentration of initiator (BPO) had the greatest effect on graft copolymerization. The concentration of emulsifier and temperature influenced the results of phase inversion. Besides, the thermal performances of modified CPP were better than untreated one. In addition, the coating obtained in optimum condition had excellent adhesion to BOPP film, and apparently improved the printing quality of the film. The printability promotion should be attributed to the different movement trend of coating’s polar and un-polar chains during the baking step, as well as the subsequent formations of new coating/substrate and coating/ink interface layer.

Polysiloxanes with Quaternary Ammonium and Polyether Groups for Silyl‐Terminated Polypropylene Oxide Waterborne Emulsions

AbstractIn this paper, polysiloxanes with pendant quaternary ammonium and polyether segments (EQAPS, nonionic–cationic silicone surfactant) were synthesized through hydrosilylation of poly(dimethylhydro)siloxane with allyl poly(ethylene glycol) acetic ester (Mn = 540) and allyl glycidyl ether, followed by a ring‐opening reaction of epoxide groups with diethyl amine and quaternization with benzyl chloride. The chemical structures of EQAPS and intermediate products were characterized by 1H‐NMR and FT‐IR spectra. The surface activity and thermal properties of EQAPS were studied with surface tension measurement and differential scanning calorimetry analysis, respectively. The results showed that the EQAPS had a much smaller critical micelle concentration value (118 mg/L) and lower glass‐transition temperature (Tg: −57 °C). The silyl‐terminated polypropylene oxide waterborne emulsions, which were substantially free from organic solvent, were prepared via a phase‐inversion emulsification technique using EQAPS as single emulsifier and/or poly(ethylene glycol) (n = 400) as cosolvent. The electrical properties of the system indicated that the phase inversion was completely accomplished. The viscosity of the emulsions with different solid contents was measured, and the results showed that the most suitable solid content was about 50 wt%. The emulsions with smaller particle size (12 μm) had better storage stability (48 days at 50 °C) and freeze–thaw stability.