Emulsion Polymerization Technology Research Articles

Abalone shells bioenhanced carboxymethyl chitosan/collagen/PLGA bionic hybrid scaffolds achieving biomineralization and osteogenesis for bone regeneration

Inspired by the formation of natural abalone shells (AS) similar to calcium salt deposition in human orthodontics, AS is used as an emulsifier in the scaffold to solve the problem of coexistence of natural and synthetic polymers and promote new bone formation. In this study, AS-stabilized and reinforced carboxymethyl chitosan/collagen/PLGA porous bionic composite scaffolds (AS/CMCS/Col/PLGA) were fabricated through the emulsion polymerization and bionic hybrid technology. As the addition of AS increased from 0.75 to 3.0 wt%, homogeneous distribution of flower-like particles could be observed on the inner surface of the scaffold, and its mechanical properties were improved. Particularly, 3.0 wt% AS-doped scaffolds (S3 and C + S3) exhibited excellent inorganic mineral deposition and osteoblast proliferation and differentiation abilities in vitro. In a SD rat calvarial defect model, they effectively promoted new bone formation in the defect and accelerated expression of osteogenic-angiogenic related proteins (COLI, OCN, VEGF). By virtue of its combined merits including good mechanical properties, inducing mineralization crystallization and facilitating osteogenesis, the 3.0 wt% AS-doped scaffold promises to be employed as a novel bone repair material for bone tissue regeneration.

Polymer Microspheres Carrying Schiff-Base Ligands for Metal Ion Adsorption Obtained via Pickering Emulsion Polymerization

Several traditional methods for producing polymer microparticle adsorbents for metal ions exist, such as bulk polymerization followed by milling and crushing the material to micron-size particles, precipitation from organic solvents, and suspension polymerization utilizing surfactants. Alternative methods that are easily scalable and are environmentally friendly are in high demand. This study employs Pickering Emulsion Polymerization Technology (PEmPTech) to synthesize nanostructured polymer microspheres that incorporate Schiff-base ligands, which can be utilized for metal ion adsorption, and specifically Cu(II) ions. Our innovative approach makes use of nanoparticle-stabilized, surfactant-free emulsions/suspensions, enabling the straightforward production of ligand-bearing microspheres while allowing for the precise modulation of the polymer matrix chemistry to maximize adsorption capacities. Through this method, we demonstrate notable enhancements in Cu(II) ion adsorption, which correlates with both the polarity of the monomers used and the concentration of Schiff-base ligands within the microspheres. Notably, our results offer insights into the structure–activity relationships essential for designing tailored adsorbents. This work provides a scalable method to produce high-performance adsorbents and also contributes to sustainable methodologies by excluding harmful surfactants and solvents.

Acrylonitrile‐styrene‐acrylate particles with different acrylonitrile contents for improving the toughness of poly(vinyl chloride) resin

AbstractPoly(butyl acrylate) grafted styrene and acrylonitrile copolymer (PBA‐g‐SAN, ASA) with core–shell structures were prepared by emulsion polymerization technology to improve the toughness of the poly(vinyl chloride) (PVC). The mechanical properties of the PVC/ASA blends were investigated. The notch impact strength of the PVC/ASA blend could reach 1200 J/m when the 13 phr ASA was added to the PVC. This was several times more than pure PVC resin. Scanning electron microscopy analysis results indicated that the improvement in impact strength of the PVC/ASA blend was attributed to shear yielding induced by ASA particles. Additionally, subtle changes in the ratio of monomers in the shell layer led to significant fluctuations in the mechanical properties of the composites. Dynamic mechanical analysis showed that the intermolecular interaction forces between ASA particles and PVC resins played a key role in improving the toughness of PVC/ASA blend.

Pickering Emulsion Polymerization Technology─Toward Nanostructured Materials for Applications in Metal Ion Extractions from Wastewaters

Pickering Emulsion Polymerization Technology─Toward Nanostructured Materials for Applications in Metal Ion Extractions from Wastewaters

Preparation and Characterization of Self-crosslinked Acrylate Emulsified with Environmentally Friendly Surfactants

The self-crosslinking polyacrylate latex was prepared via the semi-continuous seed emulsion polymerization technology that methyl methacrylate(MMA) and butyl acrylate (BA)were used as the main monomers and hexafluorobutyl methacrylate (HFMA) and monobutylitaconate (MBI) were used as the modified monomers and glycidyl methacrylate (GMA) was used as the crosslinked monomer which were emulsified with the environmentally friendly mixed surfactant of the isomeric triethylene (9) ether (E-1309) and the lauryl polyoxyethylene ether sulfosuccinate disodium salt (MES-30). The resultant latex and its film is characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimeter (DSC), laser particle sizer, contact angle determinator. The comparison of thermal stability between the resultant latex and conventional latex is carried out via the thermogravimetric analyzer (TGA). Factors, which have an influence on the properties of the resultant latex and the emulsion polymerization, are studied in detail. Results indicate that the thermal decomposition temperature of the latex film was increased from 336.9 °C to 370.1 °C The contact angle of the latex film is 82.9 ° owing to the introduction of GMA and MBI.

Dispersion, fluidity retention and retardation effect of polyacrylate-based ether superplasticizer nanomicelles in Portland cement

The superplasticizers with a high-order configuration including star, branched, clawed or corosslinked shape, have exhibited superior fluidity retention effect in cementitious mixes, but are often prepared with tedious routes. This paper employed a facile and proven emulsion polymerization technology to prepare nanomicellar polyacrylate ether superplasticizer (PAE). The precise tri-copolymer structure of PAE of poly(tert-butyl acrylate)–co-polycarboxylate-co-poly(isoprenyl polyethenoxy ether) (PtBA-co-PAA-co-PTPEG) was confirmed by 1H nuclear magnetic resonance (NMR). High-resolution transmission electron microscopy (TEM) verified the core–shell configuration of PAE and further measured colloidal nanomicelles had an average size diameter at 18–35 nm. Based on the special configuration, masses of carboxyl groups were pre-reserved in nanocores via PtBA and encapsulated PAA segments, which would be released into the paste to disperse cement particles over 4 h, during the hydrolysis of PtBA pendent chains and dissociation of nanomicelles. This process was revealed by time-dependent evaluation of spread flow and Zeta potential. Furthermore, the action mechanism of micellar PAE dispersing cement and hydrate by adsorbing onto their surfaces was directly observed by TEM testing. The retardation effect of PAE in Portland cement was evaluated by the delayed hydration heat, lower hydration rate and longer setting time, in comparison with control sample. This work offers a superior fluidity retention superplasticizer for reducing the fluidity loss of cement paste, and demonstrates the fluidity retention mechanism of colloidal PAE via nanomicelle dissociation, carboxyl release, and redispersion in alkaline cement paste.

Preparation of monodisperse polystyrene nanoparticles with tunable sizes based on soap-free emulsion polymerization technology

Herein, a one-step procedure for the preparation of monodispersed nanoparticles was achieved, with tunable size in range of around 30~300 nm based on soap-free emulsion polymerization using sodium p-styrene sulfonate as ionic comonomer. The polymerization reaction kinetics (i.e., monomer conversion, particle number, and particle size distribution) were investigated in detail. The experimental results indicated that the particle number increased in low ionic comonomer NaSS concentrations (< 10 wt%). The particle number reached maximum value at 10 wt% NaSS concentration, and minimum particle size nanoparticles (22.3 nm) were obtained. The particle size increased when NaSS concentration exceeded 10 wt%. The particle size distribution of latex gradually narrowed as the polymerization reaction was carried out due to the eversible particle coagulation process and competitive growth kinetics of a particle growth period. This method is conventional and practical for the production of nanoparticles.

Experimental investigation on plugging and transport characteristics of Pore-Scale microspheres in heterogeneous porous media for enhanced oil recovery

To reduce water cut and improve sweep efficiency of water flooding, a novel pore-scale microsphere (NMPS) as profile control agent was firstly prepared through inverse emulsion polymerization technology. Then, its physical properties were investigated, including morphology, particle size distribution, elasticity, swelling property and long-term stability. Subsequently, the plugging and transport characteristics of NMPS were studied through dual parallel core displacement experiments. And then, oil displacement efficiency was evaluated through dual parallel core displacement experiments and nuclear magnetic resonance (NMR) experiment. Experimental results demonstrated NMPS possessed favorable elasticity, water swelling property, dispersibility and long-term stability with an initial average particle size of 7.58 μm. Also, NMPS could effectively plug high permeability channel and regulate heterogeneity. Moreover, NMPS effectively diverted subsequent injected water into low permeability zone and improve sweep efficiency. As a result, 10.83–31.6% of crude oil was produced during NMPS flooding and subsequent water flooding. It was believed that NMPS was a promising candidate for heterogeneity reduction and oil recovery enhancement.

The colloidal properties of alkaline‐soluble waterborne polymers

ABSTRACTWaterborne polymer dispersions are widely used in coatings and graphic arts markets as environmentally friendly and more sustainable alternatives to solvent borne binders. Traditionally, waterborne (meth)acrylic dispersions are prepared by emulsion polymerization using low molar mass surfactants as a key ingredient to control particle size. However, these surfactants can have a negative influence on the performance of coatings such as reduced water resistance and adhesion. To mitigate the negative effects of surfactants, polymer latexes have been developed that employ alkaline‐soluble polymers as the sole stabilizer for a subsequent emulsion polymerization step. In this way surfactant‐free polymer dispersions are obtained. Despite the high commercial impact and relevance of this technology, fundamental studies regarding the physicochemical properties of the alkaline‐soluble polymers are lacking. In this article, the synthesis and colloidal properties of alkaline‐soluble waterborne methacrylic copolymers are reported. The dissolution behavior and colloidal properties of these alkaline‐soluble polymers were studied as function of molar mass, acid content, and pH. The dissolving polymer particles were characterized using static and dynamic light scattering, static and dynamic surface tension measurements, and cryogenic‐transmission electron microscopy analysis. It is concluded that the dissolution mechanism of alkaline‐soluble polymers follows a gradual process. As the pH increases deprotonation of the carboxylic acid groups swells the particle enhancing the further swelling with water. At a certain amount of base, the particles disintegrate into small polymer aggregates while the most water‐soluble polymer chains are dissolved in the water phase. An important learning is that part of the alkaline‐soluble polymer resides in very small particles (&lt;5 nm). The formation of these polymer particles below 5 nm was not reported previously and offers a new insight into the dissolution mechanism of alkaline soluble polymers. The most important parameter steering this process is the acid value of the polymer, while the molar mass plays a modest role. The understanding gained in this study can be used to further advance alkaline‐soluble polymers as stabilizer in surfactant‐free emulsion polymerization technology, improving the performance of a wide range of industrially relevant coatings. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46168.

One-Pot Preparation of Graphene-Based Polyaniline Conductive Nanocomposites for Anticorrosion Coatings

Graphene-based polyaniline (PANI/RGO), used as conductive filler, was synthesized through a new one-pot emulsion polymerization technology. Graphene dispersion (RGO) was obtained by ultrasonically reducing graphene oxide (GO) in a hot sodium hydroxide solution in the absence of any toxic reductant, such as hydrazine hydrate. Sodium dodecyl benzene sulfonate (SDBS), in which RGO sheets were dispersed, was synthesized using dodecyl benzenesulfonic acid (DBSA) and NaOH. In this RGO/SDBS mixture, polyaniline (PANI), doped with multiple acids (HCl-DBSA), was then uniformly polymerized on the surface of the RGO sheets. The experimental results showed that this reaction improved the dispersion of the RGO in the PANI system, and increased the homogeneous distribution of the formed PANI particles on the RGO surface. The synthesized composite material (PANI/RGO) had good thermal stability, electrical conductivity (about 11.71[Formula: see text]S[Formula: see text][Formula: see text][Formula: see text]cm[Formula: see text] and water dispersibility. Based on its excellent properties, the PANI/RGO was combined with waterborne epoxy resin to prepare anticorrosion coatings. The corrosion resistance of these coatings was studied using Tafel plots, along with other critical properties tested by the national standards. The results suggested that the surface resistivity of the coatings could be as high as 2.48[Formula: see text][Formula: see text][Formula: see text]10[Formula: see text] with the addition around 3[Formula: see text]wt.% of the PANI/RGO meeting good antistatic standards. In addition, the antistatic coatings had outstanding corrosion resistance, as well as tremendous physical and chemical properties.

Synthesis of large-scale, monodisperse latex particles via one-step emulsion polymerization through in situ charge neutralization

Abstract Monodisperse sub −200 nm polystyrene nanoparticles were synthesized by a facile one-step emulsion polymerization technology using sodium dodecyl sulfonate (SDS) and 2, 2′- azobis (2-methylpropionamide) dihydrochloride (AIBA) as the surfactant and initiator, respectively. The in situ neutralization between negatively charged surfactant SDS and positively charged AIBA was used to control the primary particle (or swollen micelle) volume and the extent of the particle coagulation. As the oligomeric radicals with cationic AIBA chain ends were captured by anionic swollen micelles, the electrostatic stability of swollen micelles gradually reduced, further promoting the primary particle coagulation. As a result, the initial particle number decreased with the addition of AIBA. The earlier primary particle coagulation not only enlarged the particle size, but also narrowed the particle size distribution of final the latex particles.

Preparation and adsorption behaviour of cationic nanoparticles for sugarcane fibre modification

Cationic nanoparticles with a core–shell structure and high zeta potential were prepared by two-step semi-batch emulsion polymerization and pre-emulsification technology using the cationic emulsifier hexadecyl trimethyl ammonium chloride (CTAC).

Synthesis of self-crosslinking soap-free emulsion with ketone and hydrazine to modify the properties of corrugated paper

Functional acrylate polymer emulsions were prepared using soap-free emulsion polymerization technology. Minimum film-forming temperature and glass transition temperature of the synthesized polymers were measured. The polymerization process was optimized by single factor design in the experiment. The occurrence of unique self-crosslinking reaction improves the film-forming property. The water resistance and the mechanical strength of paper are increased at the same time. Furthermore, the electrical charge of the emulsion is significantly increased with the increasing amount of the crosslinking agent, which improves the stability of the emulsion. Emulsion particles and changes of paper surfaces were observed during the treatment process. The mechanisms of polymerization and surface modification were proposed on the basis of the experimental results.

Synthesis and characterization of low-temperature self-crosslinkable acrylic emulsion for PE film ink

Abstract A low-temperature self-crosslinkable acrylic emulsion was synthesized by semi-continuous emulsion polymerization technology using methyl methacrylate (MMA), butyl acrylate (BA), acrylic acid (AA) and diacetone acrylamide (DAAM) as monomers and adipic dihydrazide (ADH) as crosslinker. Transmission electron microscope (TEM) micrograph disclosed spherical emulsion particles possess core–shell structure. Fourier transform infrared (FTIR) spectrogram showed that crosslinking reaction between CO groups of DAAM and NHNH 2 groups of ADH can occur during coating film formation at low temperature, even at room temperature. Differential scanning calorimeter (DSC) analysis indicated that glass transition temperature (Tg) of the crosslinked film is increased by 5 °C. Thermogravimetric analysis (TGA) curves demonstrated that self-crosslinking reaction improves thermal stability of film. As DAAM content increased from 0% to 2%, water absorption ratio of film decreased from 26.2% to 7.4%, adhesion ratio on the PE thin film increased from 0% to 97%. While the n (ADH)/ n (DAAM) ratio increased from 0:1 to 0.8:1, crosslinking density of films was increased from 0% to 88%, water absorption ratio decreased from 36.5% to 7.4% and adhesion ratio on the PE thin film increased from 0% to 97%. The optimal DAAM content and n (ADH)/ n (DAAM) ratio was 2% and 0.8:1 in this experiment. The emulsion has good potential application in water-based ink for PE film.

Exothermal Behavior and Particle Scale Evolution in High Solid Content One-Step Batch Emulsion Polymerization

This investigation is an extension of the previous study (Colloid Polym Sci. 291: 2385–2398), where the latex of poly(butyl acrylate) with large particle scale (300–600 nm) and high solid content was obtained via batch emulsion polymerization technology according to particle coagulation mechanism induced by electrolyte. However, some technological parameters such as the variation in the maximum reaction temperature and the time at which this maximum occurs with the initial temperature and electrolyte concentrations were not been discussed in that article. These variations play important roles in determining the design of reactor and industry production. Thus, in this study, the evolution of reaction temperature, particle scale, and number as functions of reaction time are of concern in order to confirm the effect of particle coagulation on polymerization process and finally the latex properties. Experimental results indicated that the maximum value of the polymerization system decreased with decreasing the initial reaction temperature, and with increasing electrolyte concentration. The addition of electrolyte not only reduced the maximum value of reaction temperature ranging from 92.4°C to 71°C, but also made the particle scale increase to ∼650 nm from 315 nm, and the viscosity of latexes decrease to 40.2 mPa · s from 200.1 mPa · s.

Hydrophobin: fluorosurfactant-like properties without fluorine

The stabilization of fluorous oil droplets in aqueous environment is a critical issue in the preparation of emulsified systems for biomedical applications and in emulsion polymerization technology, due to the extreme immiscibility of aqueous and fluorous phases. We present here a detailed study on the behavior of the hydrophobin HFBI, i.e. a small natural protein endowed with exceptional surface activity, at the interface between aqueous and fluorous phases. HFBI behaves as an efficient and sustainable surfactant at remarkably low concentrations and forms a strong and elastic film at the interface between the two phases. We also show proof-of-concept experiments on the use of HFBI as a surfactant in fluorous oil/water emulsified systems and in microfluidic circuits.

Study on Formulation for Epoxy Acrylic Hybrid Emulsion

The epoxy acrylate emulsion was made by hybrid emulsion polymerization. This method has simple technology, none solvent and friend to the environment. The epoxy acrylate hybrid emulsion was prepared by using core-shell emulsion polymerization technology. The factors, such as epoxy resin, emulsifier ,initiator and functional monomer, were investigated by the orthogonal experiment. The relation of interactional factors was confirmed, and one kind of steady emulsion was made. The best formulation condition of modified emulsion could be obtained when N-MA was 1%, MAA was 2%, emulsifier was 3%, epoxy resin was 6%, initiator was 0.6%. The structure of modified styrene acrylic hybrid emulsion was characterized by FT-IR, the peaks at 915cm-1 and 1251cm-1 correspond respectively to the motion of epoxy group and phenylate, so the graft polymer was confirmed.

Properties of polyacrylate latex prepared under different emulsified systems

The polyacrylate latexes were synthesized via pre-emulsified and semi-continuous seeded emulsion polymerization technology when conventional surfactant or polymerizable surfactant was used as emulsifiers. The resultant latexes and their films were characterized with the contact angle determinator and rheometer. Effect of the polymerizable surfactant on water resistance, stability and rheology of the latex was studied. Results show that the water resistance of film is increased first then decreased with the increase of the amount of the polymerizable surfactant. There exists the optimum value of the amount of the polymerizable surfactant for the water resistance of the film. In comparison with the latex prepared with the conventional surfactant, both the mechanical stability and the freezing-thaw stability of the latex are improved when the polymerizable surfactant is used during the course of the emulsion polymerization. The resultant latex has rheological properties of pseudo-plastic fluid and belongs to non-Newtonian fluid.

Influence of the Reactive Emulsifier-HPMA on the Properties of the Acrylate Emulsion

The acrylate emulsion was prepared via pre-emulsified and semicontinuous seeded emulsion polymerization technology when nonreactive emulsifiers such as sodium dodecyl-benzenesulfonate (DSB) are replaced with reactive emulsifiers such as sodium2-hydroxy-3-(methacryloyloxy)propane-1-sulfonate (HPMAS). Influence of HPMAS on the particle size, water resistance, viscosity, rheology, and stability of the emulsion was studied. Results show that the particle size and the viscosity of the emulsion are increased with the added amount of HPMAS. However, water resistance of film first is increased and then decreased with the increase of the added amount of HPMAS. The water resistance of the film is best when the added amount of HPMAS is 2.0%. The viscosity of the emulsion is increased with the increase of the added amount of HPMAS. Both the mechanical stability and the freezing-thaw stability of the emulsion are improved when DSB is replaced with HPMAS during the course of the emulsion polymerization. The emulsion is of rheological properties of pseudo-plastic fluid and belongs to non-Newtonian fluid.

Synthesis and Properties of Acrylic Emulsion with Core-Shell Structure in Antifouling Paints

Water based resins have an important application in environmental benign coating to reduce the volatile organic compounds (VOC). This work describes the synthesis and characterization of an acrylic emulsion with core-shell structure by using pre-emulsion and seed emulsion polymerization technology for antifouling paints. The results indicate that when the ratio of soft and hard monomer is in the range of 1:1~2:1 and the amount of cross-linking agent is added, the comprehensive properties of acrylic emulsion are good. Although the coatings were found to develop a whitish aspect (blushing) due to water retrodiffusion, the films did not break and splint, further research are focused to increase their comprehensive properties for marine antifouling application.