María Paulis

María Paulis
University of the Basque Country | UPV/EHU · Applied Chemistry

PhD

About

123
Publications
14,283
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2,881
Citations
Additional affiliations
March 2003 - present
University of the Basque Country
Position
  • Professor (Associate)

Publications

Publications (123)
Article
Particle size evolution in seeded semibatch emulsion polymerization is monitored by two real‐time monitoring techniques: online turbidity spectroscopy (TUS) and inline photon density wave spectroscopy (PDWS). An automatic dilution system that withdraws a sample from the reactor and upon dilution transfers to the measurement cell is used for the onl...
Article
Particle size and particle size distribution (PSD) are important properties of polymer latexes because they strongly affect the film formation and the rheological properties of the latexes. Thus, monitoring the particle size is of paramount importance during the production of waterborne polymeric dispersions, for which online/inline measurements of...
Article
Full-text available
Polymer colloids are complex materials that have the potential to be used in a vast array of applications. One of the main reasons for their continued growth in commercial use is the water-based emulsion polymerization process through which they are generally synthesized. This technique is not only highly efficient from an industrial point of view...
Article
In this work, solvent‐free waterborne polyurethane‐poly(meth)acrylate hybrid dispersions that can be used to formulate anticorrosive paints are synthesized. To achieve the anticorrosive protection, a phosphate containing polymerizable surfactant, Sipomer PAM 200 is incorporated to the hybrids. The presence of phosphate groups can produce an iron ph...
Article
Full-text available
The present work takes advantage of green electrospinning to create novel composite multifunctional nanofibers (NFs) bearing inorganic nanoparticles (NPs), more specifically quantum dots (QDs), cerium oxide nanoparticles (CeO2 NPs) and iron oxide nanoparticles (Fe3O4 NPs). This is achieved by first encapsulating the desired inorganic NPs into polym...
Article
A two-pot-one-pack waterborne crosslinking system is studied by following the crosslinking and interdiffusion between the polymer particles functionalized with acetoacetoxy on one hand and with polyethyleneimine on the other. FTIR spectroscopy and rheological measurements are used to follow the evolution of crosslinking, while pyrene excimer fluore...
Article
Emulsion polymerization of (meth)acrylic bio-based monomers is a promising method to obtain waterborne coatings with reduced carbon footprint. However, the high hydrophobicity of some bio-based monomers can hinder the straightforward incorporation of such monomers in waterborne dispersions. In this work, we explore the copolymerization of bio-based...
Article
A kinetic study of the crosslinking reaction between waterborne polymer particles functionalized with aceto acetoxy ethyl methacrylate (AAEMA) and polymer particles functionalized with hexamethylene diamine (HMDA) is presented. Seeded emulsion polymerization is used to synthesize the polymer particles and the crosslinking reaction is followed durin...
Article
Full-text available
Four strategies to incorporate a fluorinated monomer (perfluoro octyl acrylate, POA) into a waterborne polymeric dispersion are investigated. Due to the very low water solubility of the POA monomer, three of the strategies use miniemulsion droplets containing the whole POA monomer in the initial charge. The rest of the comonomers of the formulation...
Article
One of the objectives of the waterborne coatings industry is to reduce or eliminate solvents out of latex paints, maintaining or increasing the mechanical performance in a way that makes industrial adaptation as plain and economical as possible. This task has been tackled by the use of temporary oligomer plasticizers (TOP) in this work. The aim of...
Article
The incorporation of organic corrosion inhibitors into waterborne coatings is optimized in this work. Herein, p‐coumaric acid (4‐hydroxycinnamic acid) is modified by a butyl radical and its effectiveness as an anticorrosive free inhibitor in solution is confirmed by potentiodynamic polarization. The molecule is then successfully incorporated into w...
Article
Full-text available
In this paper, two phosphate functionalized acrylic binders are formulated to yield direct-to-metal paints without using corrosion inhibitors. The difference between both binders is the addition of polystearylacrylate crystalline nanodomains in one of them, and an amorphous methyl methacylate-co-butyl acrylate copolymer in the other. The water sens...
Article
Full-text available
Green electrospinning is a relatively new promising technology in which a polymer (latex) can be spun from an aqueous dispersion with the help of a template polymer. This method is a green, clean and safe technology that is able to spin hydrophobic polymers using water as an electrospinning medium. In this article, a systematic study that investiga...
Article
Full-text available
CeO2 nanoparticles were incorporated in waterborne binders containing high biobased content (up to 70%) in order to analyze the anticorrosion performance for direct to metal coatings. Biobased binders were synthesized by batch miniemulsion polymerization of 2-octyl acrylate and isobornyl methacrylate monomers using a phosphate polymerizable surfact...
Preprint
Full-text available
Nanoscale Fourier transform infrared spectroscopy (nano-FTIR) is an emerging technique that allows for label-free chemical nanoimaging. Here, we introduce its application to studying multicomponent nanostructured polymer particles synthesized by emulsion polymerization and demonstrate its excellent sensitivity to local chemical composition via hype...
Article
A thin stand-alone waterborne coating that combines hydrophobicity and a built-in ability to in-situ phosphatize low carbon steel substrates, avoiding flash rust in the interface is presented. Despite the hydrophobicity of the coating is enhanced by the presence of a fluorinated comonomer, the barrier protection is substantially decreased as compar...
Article
Full-text available
The film formation step of latexes constitutes one of the challenges of these environmentally friendly waterborne polymers, as the high glass transition (TG) polymers needed to produce hard films to be used as coatings will not produce coherent films at low temperature. This issue has been dealt by the use of temporary plasticizers added with the o...
Article
Full-text available
AB diblock waterborne copolymers made of styrene (St) and 2-ethylhexyl acrylate (2EHA) were synthesized by means of two-step reversible addition fragmentation chain transfer (RAFT) (mini)emulsion polymerization. Monofunctional asymmetric RAFT agent was used to initiate the polymerization. The hard polystyrene “A” block was synthesized via miniemuls...
Article
The aim of this work is to better understand the effect that different functional monomers and amounts have on the dispersion of calcium carbonate (CaCO3) fillers in waterborne acrylic coatings. This will allow to improve the final performance of coatings at a certain pigment volume concentration (PVC) or to increase the PVC without significant los...
Article
In the present work a thin, stand-alone waterborne coating with excellent anticorrosion performance was successfully designed thanks to a built-in ability to in-situ phosphatize low carbon steel substrates. During film formation, the phosphate functionalities, incorporated by using a phosphate functional surfmer, were able to interact with steel le...
Article
The aim of this work is to isolate the interaction between waterborne acrylic polymer and calcium carbonate (CaCO3) fillers, in order to build a deeper understanding of the factors influencing the dispersion and adhesion of CaCO3 fillers to acrylic binders. Therefore, along this work waterborne paint-like blends with applicable rheology have been p...
Article
Full-text available
High molecular weight waterborne ABA block copolymers of styrene (St) and 2-ethylhexyl acrylate (2EHA) containing hard and soft domains were synthesized by means of RAFT (mini)emulsion polymerization using a bifunctional symmetric S,S-dibenzyl trithiocarbonate (DBTTC) RAFT agent. Miniemulsion polymerization was initially used for the synthesis of t...
Article
A novel waterborne coating has been successfully designed combining good barrier properties and a built-in ability to in situ phosphatize low carbon steel substrates. The physical barrier protection was achieved by a homogeneous dispersion of crystalline nanodomains in the polymer matrix, which was achieved from the coalescence of polymer particles...
Article
The benefits of polymerizing very insoluble monomers in aqueous media, avoiding the use of energy‐intensive procedures, by implementing two novel synthesis techniques based on the emulsifier combination in emulsion polymerization and on miniemulsification by phase inversion temperature are investigated. The performance of standalone polymers consis...
Patent
Full-text available
The present invention is directed to a method for producing a coating system providing corrosion-protective properties when applied to metal surfaces, particularly in the form of a water-based (waterborne) composition, preferably in the form of a dispersion (i.e. emulsion or latex, respectively), as well as to coating system thus produced and to it...
Article
Full-text available
Waterborne ABA block copolymers of stearyl acrylate (SA) and 2-ethylhexyl acrylate (2EHA) containing crystalline A block and soft middle B block, were synthesized via two-step reversible addition fragmentation chain transfer (RAFT) polymerization, using S,S-dibenzyl trithiocarbonate (DBTTC) bifunctional RAFT agent. First, miniemulsion polymerizatio...
Article
Hybrid nanofibers containing CdSe/ZnS quantum dots have been produced by electrospinning of hybrid latexes to characterize the electro‐optical behavior of this novel luminescent sensing material. The latexes are synthesized by seeded semi‐batch emulsion polymerization yielding cross‐linked core‐shell PS/QDs/PMMA particles with efficiently encapsula...
Article
The aim of this work has been to study the factors affecting the interaction between calcium carbonate (CaCO3) filler and acrylic binders in waterborne coatings. Therefore, the minimum amount of additives has been used in order to isolate the interaction between the filler and the binder, while the production of an applicable coating was assured. I...
Article
Hybrid core/shell polymer particles with co-encapsulated quantum dots (QDs) (CdSe/ZnS) and CeO2 nanoparticles have been synthesized in a two stage semi-batch emulsion polymerization process. In the first stage, both inorganic nanoparticles are incorporated into cross-linked polystyrene (PS) particles by miniemulsion polymerization. This hybrid disp...
Article
Miniemulsion preparation by low-energy phase inversion temperature (PIT) was performed for lauryl methacrylate (LMA) using polyethoxylated non-ionic emulsifiers. The minimum emulsifier content (4.5. wt%) and maximum amount of monomer (33. wt%) that led to stable miniemulsions was optimized and the corresponding miniemulsions polymerized. Depending...
Article
Full-text available
A nanohybrid waterborne binder was synthesized by miniemulsion polymerization with the incorporation of ZnO nanoparticles in order to increase the corrosion protection capability. This system was compared to a neat waterborne binder and to a physical blend of the binder with an aqueous ZnO nanoparticles dispersion. The hybrid dispersion was charact...
Article
This work analyses the effect of UV irradiation in a pure acrylic film, and two hybrid films, one with 1% CeO2 nanoparticles and another with 1% of ZnO nanoparticles. The long term durability of the polymeric films was studied by accelerated UV exposure ageing. The changes occurring in the polymeric films were analyzed by measuring thermal properti...
Article
Water-borne polymeric dispersions of superhydrophobic monomers can be catalogued as high performance materials, particularly towards applications involving excellent water-barrier properties. Their industrial production however is challenging due to their low water solubility. This work illustrates the polymerization of superhydrophobic monomers la...
Article
We present an efficient method for the encapsulation and fixation of octadecylamine coated CdSe/ZnS quantum dots. This is achieved by incorporating the QDs into core-shell particles made of PS/DVB (core)/PMMA/DVB (shell) cross linked polymeric phases synthesized in two stages. The first stage comprises the production of a hybrid PS/DVB core with QD...
Article
The preparation of poly(ionic liquid) microcapsules from liquid marbles (3–20 μL) with additional magnetic properties is described in this work. These microcapsules show excellent oil absorption properties and selectivity versus water together with easy manipulation for oil capture and recovery.
Article
New methods for preparing polymeric nanoparticles are actively being investigated such as self-assembly of amphiphilic block copolymers, self-crosslinking of single-chain macromolecules, nanoprecipitation or emulsion-miniemulsion polymerizations. However, most methods require multi-step synthesis, controlled polymerization mechanisms and tedious pu...
Article
The effect of the acidic hairy layer length on the interdiffusion of polymer between particles and as a consequence on the mechanical properties of the films produced from waterborne coatings has been studied. In order to isolate this effect, latexes with the same particle diameter and molecular weight but stabilized with poly(acrylic acid)-block-p...
Article
Hybrid waterborne dispersions provide improved performance in established applications and allow targeting new applications that are out of reach of the conventional homogeneous latexes. They are product-by-process materials that are produced by either emulsion or miniemulsion polymerization and whose characteristics are determined in the reactor....
Article
Coalescence and interdiffusion during film formation of waterborne polymers stabilized by commercial high T g alkali-soluble resins (ASRs) were evaluated through environmental scanning electron microscopy and fluorescence resonance energy transfer. The observed effects were used to justify the mechanical properties. The presence of a hard barrier b...
Conference Paper
Full-text available
This work illustrates the benefits of the inclusion of superhydrophobic monomers in the synthesis of waterborne coatings to improve properties of such as: water contact angle, water soaking resistance, water vapour resistance and early water resistance. Superhydrophobic monomers have been successfully polymerized in aqueous media, while avoiding th...
Article
Acrylic/ZnO hybrid latexes were synthesized through a two-step emulsion polymerization process. First, a hybrid seed was synthesized by miniemulsion polymerization, which contained all the hydrophobically modified ZnO nanoparticles. Subsequently, this hybrid seed was employed in a seeded semibatch emulsion copolymerization yielding high solids cont...
Article
A simple method to prepare multifunctional liquid marbles and dry water with magnetic, color and fluorescent properties is presented. Multifunctional liquid marbles were prepared by encapsulation of water droplets using flocculated polymer latexes. First the emulsion polymerization reaction of polystyrene and poly(benzyl methacrylate) was carried o...
Article
Full-text available
This work presents the in situ synthesis of crosslinked polymer/graphene nanocomposites by seeded semicontinuous emulsion polymerization. The OH functionalities on the rGO platelets and in the polymer chains (introduced by functional monomer hydroxylethyl methacrylate) were used as reactive sites, linked by the presence of NCO terminated polyuretha...
Article
Monomer droplet nucleation has been successfully tracked in a seeded semibatch miniemulsion polymerization with miniemulsion feeding. Taking advantage of the marker capacity of CeO2 nanoparticles two polymerizations were designed. In the first one the seed contained nanoceria while a blank monomer miniemulsion was fed to the reactor and in the seco...
Article
The evolution of the morphology of an acrylic/CeO2 hybrid latex synthesized by a two step seeded semibatch emulsion polymerization process was investigated. The seed was produced by batch miniemulsion polymerization and in the second step a neat monomer preemulsion was fed to the seed to increase the solids content and encapsulate the inorganic mat...
Poster
Full-text available
As reações de geração de radicais livres via processos redox, e sua utilização para a iniciação de cadeias e partículas poliméricas, em sistemas heterofásicos, mediante polimerização radicalar, é conhecida desde a segunda década do século passado. A despeito de sua ampla utilização industrial, os mecanismos para estas reações são ainda muito pouco...
Article
Full-text available
The present paper describes a versatile route to modify and stabilize ceria nanoparticles with a radical initiator, 4,4′-Azobis(4-cyanovaleric acid) (ACVA), allowing a strong interface to be formed via grafting of polymers from the surface. This leads to the successful encapsulation of cerium oxides nanoparticles in a poly-(methyl methacrylate) mat...
Article
A dispersion of CeO2 nanoparticles and nanorods stabilized with nitrilotriacetic acid (NTA) and 4,4’-Azobis(4-cyanovaleric acid) (V-501) initiator has been used to initiate the emulsion polymerization of acrylic monomers, yielding stable hybrid CeO2 nanoparticles-nanorods/polyacrylate latexes for the first time. Films casted from these hybrid latex...
Article
Polymer latexes stabilized with different acrylic acid (AA) chain lengths (controlled by Reversible Addition-Fragmentation Chain Transfer) were synthesized following different routes: Starting from poly(acrylic acid) (PAA) chains as surfactant precursors or starting from poly(acrylic acid)-block-poly(butyl acrylate) (PAA-b-PBA) copolymers as surfac...
Article
A detailed kinetic Monte Carlo simulation was used to predict the characteristics of the batch miniemulsion polymerization of an isocyanate and an acrylic monomer mixture that contains a hydroxyl functional monomer (HEMA). The simulation takes into account the simultaneous polyaddition of the polyurethane prepolymer with the hydroxyl group of HEMA...
Article
Individual "liquid marbles" were prepared by encapsulation of water droplets using flocculated polymer latexes stabilized with poly(ionic liquid)s. At first, the emulsion polymerization of poly(styrene) and poly(methyl methacrylate) using different poly(ionic liquid)s as stabilizers was investigated. Stable latexes composed of spherical polymer par...
Article
Molecularly imprinted polymers (MIPs) of propranolol were synthesized by bulk polymerization. Methacrylic acid (MAA) was selected as the functional monomer and symmetrical dimethacrylate crosslinkers of different length between the double bound as well as an asymmetrical crosslinker containing an allylic and a methacrylic double bond were investiga...
Article
Molecular structure plays a crucial role determining the final properties of pressure sensitive adhesives. Here, we demonstrate that the molecular structure of polyurethane/(meth)acrylic hybrids synthesized by miniemulsion photopolymerization changes during the storage of the dispersion at room temperature, because of the spontaneous formation of n...
Patent
NOVELTY - Producing a nanocomposite dispersion comprising composite particles of inorganic nanoparticles and organic polymers in a continuous phase involves a) providing inorganic nanoparticles; b) modifying the inorganic nanoparticles by using at least one dispersing agent via chemical reaction; c) subsequently, combining the surface-modified inor...
Article
The effect of the incorporation of three different surface modified silicas on the final properties of poly(vinyl acetate) (PVAc) latex based wood adhesives is assessed. It is shown that the compatibility and reactivity of the silica with the polymer determines its state of dispersion throughout the polymer matrix. While silicas revealing the best...
Article
By using a two-step polymerization process, it was possible to encapsulate clay platelets within polymer particles dispersed in water. First, seed polymer particles with chemically bonded clay were obtained by batch miniemulsion polymerization. Then, the clay was buried within the particles by the addition of neat monomer in a second step. The fina...
Data
Hybrid acrylic/CeO2 latexes with solids content as high as 50 wt% and CeO2 content up to 1 wt% are synthesized by a seeded semibatch emulsion polymerization process. TEM images show that CeO2 nanoparticles are randomly located within the polymer particles. The 2D trasmission electron microscopy (TEM) images are not conclusive to elucidate if CeO2 i...
Article
Full-text available
CeO2 nanoparticles have been successfully incorporated into acrylic latex particles with an excellent homogeneous distribution (mostly one inorganic particle per polymer particle) and limited aggregation (inorganic nanoparticles predominantly in the 17–26 nm range, when the original cerium oxide dispersion had a volume average diameter of 8 nm). Th...
Article
The use of sodium montmorillonite clay as stabilizer in the surfactant-free emulsion polymerization of n-butyl acrylate/styrene (n-BA/S) was assessed. It was shown that the use of the clay alone did not yield the desired armored latex particles. A functional comonomer, that is a phosphate ester of poly(ethylene glycol) monomethacrylate, was used to...
Article
In the film formation of latex, particle deformation can occur by processes of wet sintering, dry sintering, or capillary action. When latex films dry non-uniformly and when particles deform and coalesce while the film is still wet, a detrimental skin layer will develop at the film surface. In their process model, Routh and Russel proposed that the...
Article
Full-text available
The morphology and adhesive properties of waterborne films from n-butyl acrylate/methyl methacrylate/montmorillonite clay hybrid polymer latexes which were synthesized by miniemulsion polymerization in the presence of a reactive organoclay ((2-methacryloylethyl) hexadecyldimethylammonium modified montmorillonite, CMA16) were investigated. It was fo...
Article
A new methodology for quantitative characterization of the coalescence process of waterborne polymer dispersion (latex) particles by environmental scanning electron microscopy (ESEM) is proposed. The experimental setup has been developed to provide reproducible latex monolayer depositions, optimized contrast of the latex particles, and a reliable r...
Article
Films cast from multiphase polymer particles have the potential to combine the properties of their components synergistically. The properties of the film depend on the hybrid polymer architecture and the film morphology. However, how the polymer microstructure and particle morphology are transformed during film formation to determine the film morph...
Article
The synthesis of acrylic latexes filled with silica nanoparticles have been developed in the present work. Moreover, a exhaustive study of the influence of the synthesis conditions on the latex characteristics has been performed. The latex particles morphology has been observed using transmission electron microscopy (TEM) showing a raspberry morpho...
Article
Miniemulsion polymerization allows the synthesis of a broad range of materials, which are not obtainable by means of other polymerization processes in dispersed media such as conventional emulsion polymerization. However, the industrial implementation of the miniemulsion polymerization is being hindered by the miniemulsification process, which may...
Article
The kinetics of the emulsion copolymerization of methyl methacrylate/butyl acrylate (MMA/BA = 50/50) in the presence of sodium montmorillonite (Na-MMT) was investigated. Sodium laurylsulfate was used as surfactant at different concentrations and potassium persulfate as initiator. Two series of experiments were carried out at 30% and 10% solids cont...
Article
Polymer/clay hybrids exhibit often outstanding mechanical, thermal, barrier and flammability properties that have made them very attractive for the development of a new class of materials; the so-called nanocomposites. The enhanced properties of the nanocomposite materials, as compared with conventional materials, comes from the small size of the c...
Article
Waterborne polymer nanocomposites containing carbon nanotubes, clay platelets, laponite disks and other spherical/nonspherical nanofillers have been the focus of many recent investigations. The miniemulsion polymerization has proved to be a powerful technique to create new hybrid waterborne nanocomposites with enhanced properties. It is necessary t...
Article
Grafting of alkyd resin to the acrylic polymer is needed to fully exploit the possibilities of these hybrids; but in the curr