Proyectos de investigación en los cuales colabora: a) Desarrollo de sistemas polimé... more Proyectos de investigación en los cuales colabora: a) Desarrollo de sistemas poliméricos para formulaciones de pinturas y recubrimientos en base acuosa. Estudios sobre sistemas poliméricos compatibles en medio acuoso, para reducir y/o eliminar el uso de solventes orgánicos (VOC). b) PID N° 2013-0010 “Incorporación de nanopartículas de óxidos inorgánicos en recu-brimientos industriales de alta resistencia a la abrasión” con la empresa Prokrete Ar-gentina S.A.. c) “Síntesis, caracterización y aplicaciones de materiales poliméricos”, (UTN, Código 25/I047). Período 01/01/2011 – 31/12/2014. Director J.I. Amalvy. d) Proyecto de la Agencia Nacional de Promoción Científico y Tecnológica, PICT 2011 N° 0238 “Materiales poliméricos compuestos, sintéticos y naturales, con aplicaciones en medio am-biente e industria&rdquo...
Proyectos de investigación en los cuales colabora: a) Desarrollo de sistemas polimé... more Proyectos de investigación en los cuales colabora: a) Desarrollo de sistemas poliméricos para formulaciones de pinturas y recubrimientos en base acuosa. Estudios sobre sistemas poliméricos compatibles en medio acuoso, para reducir y/o eliminar el uso de solventes orgánicos (VOC). b) PICT 2008 N° 2218 “Metalofármacos de vanadio y cobre: síntesis, caracterización y activi-dad biológica en cultivos celulares por exposición directa”, Director: Susana B. Etcheverry. 09/2010 – 09-2013 c) “Síntesis, caracterización y aplicaciones de materiales poliméricos”, (UTN, Código 25/I047). Período 01/01/2011 – 31/12/2013. d) Red SPIDER “Statistical Physics in Diverse Realisations”, (IRSES N° 295302). 7mo programa marco de la UE
En la actualidad, existe una tendencia creciente de utilizar polímeros naturales por las caracter... more En la actualidad, existe una tendencia creciente de utilizar polímeros naturales por las características de ser renovables, biocompatibles, biodegradables y en muchos casos económicamente viables en aplicaciones varias. En particular los almidones provenientes de diferentes fuentes han sido empleados para elaborar recubrimientos para alimentos. Sin embargo requieren de la adición de plastificantes para reducir la rigidez y tendencia al agrietado. Una práctica común es la incorporación de glicerol, alcohol polivinílico (PVA) o combinaciones de ellos. La plastificación por glicerol es temporaria y puede migrar hacia el alimento. El PVA, por su parte, es un polímero de amplio uso en la industria por ser no-tóxico, soluble en agua, biocompatible y biodegradable, con resistencia química y alta flexibilidad, así como buenas propiedades de barrera para el oxígeno y los aromas. Sin embargo, la plastificación empleando PVA como único plastificante requiere de la incorporación de cantidades i...
The high doses of sulfadiazine (SDZ), used in synergistic combination with pyrimethamine, are mai... more The high doses of sulfadiazine (SDZ), used in synergistic combination with pyrimethamine, are mainly responsible for severe side effects and discontinuation of toxoplasmosis treatments. In the search for new strategies that improve the efficacy of treatments with reduced doses of SDZ, we have determined the performance of cationic G4 (DG4) and anionic G4.5 (DG4.5) poly(amidoamine) (PAMAM) dendrimers to act as SDZ nanocarriers. Both dendrimers could efficiently load SDZ (SDZ-DG4 and SDZ-DG4.5) up to a ratio of 30 molecules SDZ per dendrimer molecule. The MTT assay on Vero and J774 cells showed no cytotoxicity for DG4.5 and its SDZ complex incubated between 0.03 and 33 microM of dendrimer concentration. On the other hand, DG4 and its SDZ complex resulted cytotoxic when incubated at dendrimer concentrations higher than 3.3 microM. Finally, complexes and empty dendrimers were in vitro tested against Vero cells infected with RH strain of Toxoplasma gondii along 4h of treatment. For SDZ-D...
The development of water-based anticorrosive systems as well as the assessment of its anticorrosi... more The development of water-based anticorrosive systems as well as the assessment of its anticorrosive properties through different conventional tests are discussed in this work. Steel panels coated with different painting systems were subjected to standardized (salt spray, humidity chamber, adhesion, and flexibility) tests. The binder used in this research was prepared in the laboratory by emulsion polymerization of styrene and acrylic monomers. Three ecological pigments were used: two phosphate-based and one prepared in the laboratory using a tannin-based recipe. Two levels of pigment charge were tested. The commonly used zinc tetraoxychromate pigment in solvent-borne coatings was included as reference. It was found that the ecologically friendly formulations tested in this work protect steel against corrosion effectively. The zinc tetraoxychromate pigment was not suitable for the binder used in this work as judged by the inferior corrosion protection of formulations containing it. Possible reasons based on binder-pigment interactions are discussed.
En este trabajo, se presentan los cursos de Español 3 y Español 4 organizados especialmente a ped... more En este trabajo, se presentan los cursos de Español 3 y Español 4 organizados especialmente a pedido de la Universidad de Leiden. De acuerdo con los programas provistos por el Departamento de Español de esta universidad holandesa, se seleccionaron los contenidos gramaticales en relación con los contenidos funcionales. Para ello, se elaboraron actividades que propiciaban las cuatro macrohabilidades-leer, escuchar, hablar y escribir utilizando materiales auténticos que incluían cuestiones culturales relevantes de la Argentina. Se expondrán algunos ejemplos de los materiales utilizados, la metodología con la cual se abordaron y algunos resultados obtenidos en las producciones de los alumnos.
A pH-sensitive blend of polyurethane (PU) and poly(2-(diethyl amino)ethyl methacrylate (PDEA) wit... more A pH-sensitive blend of polyurethane (PU) and poly(2-(diethyl amino)ethyl methacrylate (PDEA) with good film-forming capacity was prepared from the corresponding aqueous dispersions. The polymer matrix was first characterized by using FTIR, DSC, water vapor transmission and water swelling capacity at different pHs. The drug release profile of films was evaluated using a vertical Franz Cell and theophylline as model drug. The water swelling degree increases from 54 to 180% when the pH of the medium is changed from 6 to 2, demonstrating the pH-responsive behavior of the film. The in-vitro release studies indicate that an anomalous transport mechanism governs the theophylline release.
The influence of a tannin pretreatment applied to slightly rusted steel panels on the anticorrosi... more The influence of a tannin pretreatment applied to slightly rusted steel panels on the anticorrosive performance of alkyd paint systems has been investigated using electrochemical impedance spectroscopy (EIS) and open circuit potential measurements. From EIS and corrosion potential data analysis it was found that (1) there is not a significant influence of the tannin pretreatment on the anticorrosive protection level,
Polyurethane/acrylate hybrid composites in a broad range of composition (10, 30, 50, 70 and 90 wt... more Polyurethane/acrylate hybrid composites in a broad range of composition (10, 30, 50, 70 and 90 wt.% of acrylic content), were obtained by emulsion polymerization of acrylic monomers (methyl methacrylate/n-butyl acrylate/acrylic acid mixture) in the presence of preformed polyurethane chains with polymerizable terminal vinyl groups. Blends with the same acrylic content were also prepared by mixing polyurethane and acrylic dispersions. Samples were characterized by SEC, DLS, FTIR, UV, TEM, AFM, SAXS/WAXS and gel fraction content. Mechanical properties, Buccholz and pencil hardness, surface roughness and water contact angle of films were also determined. The effect of the acrylic content on morphology and film properties was also evaluated. Hybrids are crosslinked systems showing changes in the particle and film morphologies with increasing acrylic content. The properties of hybrid films show a non-linear behavior with the increase of the acrylic component, while physical blends exhibit a gradual behavior from PU to AC. FTIR results indicate better acrylic-polyurethane compatibility in hybrid systems than in physical blends. Hybrid composites with up to 70 wt.% of acrylic component are homogeneous by SAXS. On the other hand, AFM results show that blends are phase segregated systems at all composition levels.
This work is part of studies of drying of paints using dynamic speckle interferometry (DSI), a te... more This work is part of studies of drying of paints using dynamic speckle interferometry (DSI), a technique based on the use of laser light. DSI is a non-invasive method that does not disturb the drying process. The sample is illuminated by a laser light from a source and the images corresponding to a phenomenon of interference called speckle are registered. If the surface shows activity, the interference pattern changes in time. Following this evolution, we can analyze the drying process by means of an image-processing algorithms. Therefore, it is possible to determine the temporal evolution of surfaces with different drying times. In this work the application of DSI to follow the drying process of paints with different drying times and drying velocities is presented. Different types of paints applied in different thicknesses of wet film and aerosol spray were analyzed. Quantitative measurements were obtained by analysis of the inertia moment of the co-occurrence matrix. Also, qualitative measurements were obtained by sample activity. A new approach for monitoring simultaneously zones with different drying times is discussed and applied. As in previous work, results were compared with those from conventional techniques such as gravimetric analysis providing a good correlation between both techniques.
The rheological and morphological properties and in vitro theophylline release of tertiary amineb... more The rheological and morphological properties and in vitro theophylline release of tertiary aminebased microgels were evaluated. The testing of such a formulation through in vitro diffusion experiments revealed that the release of theophylline from the microgels was pH-dependent and differs significantly with respect to a nonresponsive gel like scleroglucan (Scl). The microgels were obtained from 2-(diethyl amino) ethylmethacrylate (DEA) in the presence of a bifunctional crosslinker at pH 8-9. As the resulting microgels are pH-responsive and an increase in viscosity from high to low pH range is exhibited, the in vitro release of theophylline as model drug was studied at different pHs of both the matrix and the receptor medium. The release behaviors of PDEA-based microgels were compared to nonresponsive natural gel Scl, studied previously. For microgels, diverse release patterns were found at different acidity conditions. This observation seems to be related to complex diffusion phenomena and the different gel structure obtained for samples prepared at dissimilar pH.
Polyurethane (PU)/acrylate hybrids with different acrylic contents (10, 30, 50, 70, and 90 wt %) ... more Polyurethane (PU)/acrylate hybrids with different acrylic contents (10, 30, 50, 70, and 90 wt %) were prepared by the polymerization of acrylic monomers in the presence of preformed PU chains with polymerizable terminal vinyl groups. Films obtained by the casting of polymer dispersions before and after thermal annealing were characterized by dynamic light scattering, Fourier transform infrared spectroscopy, transmission electron microscopy (TEM), TEM electron energy-loss spectroscopy, differential scanning calorimetry, and gel fraction determination. Small-angle X-ray scattering (SAXS), wide-angle Xray scattering, mechanical properties testing, atomic force microscopy, water contact angle testing, Buchholz hardness testing, and roughness testing of the films were also performed. The effects of the acrylic content and thermal treatment on the structure and properties were determined. TEM showed that a core-shell morphology was formed during polymerization. When the acrylic content increased, smaller particles without core-shell morphologies were observed. TEM energy-loss spectroscopy studies confirmed this observation. Systems with up to 50 wt % acrylic component were homogeneous, as determined by SAXS, before and after thermal annealing. An attempt to incorporate a higher amount of acrylic component led to phase-separated materials with a different morphology and, therefore, different properties. The relationship between the acrylic content and properties did not follow linear behavior. V
The development of glossy topcoat one-pot exterior paint formulations using water-based polyureth... more The development of glossy topcoat one-pot exterior paint formulations using water-based polyurethane/acrylates hybrid binders as well as the assessment of its properties through different conventional tests is discussed in this work. Polyurethane (PU) anionomer having 2-ethoxymethacrylate terminal groups was prepared following a prepolymer mixing process. This prepolymer was chain extended in aqueous solution and after addition of acrylic monomers radical polymerized. Paints were prepared using titanium dioxide as unique pigment. Panels coated with air-dried paints with three pigment to volume concentration (PVC) values were subjected to standardized tests including adhesion, flexibility, gloss and color determination. Accelerated weathering tests were carried out to evaluate changes in properties, especially gloss and color, of painted panels. Solvent-based acrylic and polyurethane paints were included as high gloss quality reference coatings. It was found that air-dried formulations based on hybrid polyurethane/acrylic with up to 50 wt.% of acrylic component, show a gloss as high as 70 and the relative gloss change after accelerated weathering test is lower than the pure solvent-based acrylic and polyurethane paints.
The development of glossy topcoat one-pot exterior paint formulations using water-based polyureth... more The development of glossy topcoat one-pot exterior paint formulations using water-based polyurethane/acrylates hybrid binders as well as the assessment of its properties through different conventional tests is discussed in this work. Polyurethane (PU) anionomer having 2-ethoxymethacrylate terminal groups was prepared following a prepolymer mixing process. This prepolymer was chain extended in aqueous solution and after addition of acrylic monomers radical polymerized. Paints were prepared using titanium dioxide as unique pigment. Panels coated with air-dried paints with three pigment to volume concentration (PVC) values were subjected to standardized tests including adhesion, flexibility, gloss and color determination. Accelerated weathering tests were carried out to evaluate changes in properties, especially gloss and color, of painted panels. Solvent-based acrylic and polyurethane paints were included as high gloss quality reference coatings. It was found that air-dried formulations based on hybrid polyurethane/acrylic with up to 50 wt.% of acrylic component, show a gloss as high as 70 and the relative gloss change after accelerated weathering test is lower than the pure solvent-based acrylic and polyurethane paints.
Proyectos de investigación en los cuales colabora: a) Desarrollo de sistemas polimé... more Proyectos de investigación en los cuales colabora: a) Desarrollo de sistemas poliméricos para formulaciones de pinturas y recubrimientos en base acuosa. Estudios sobre sistemas poliméricos compatibles en medio acuoso, para reducir y/o eliminar el uso de solventes orgánicos (VOC). b) PID N° 2013-0010 “Incorporación de nanopartículas de óxidos inorgánicos en recu-brimientos industriales de alta resistencia a la abrasión” con la empresa Prokrete Ar-gentina S.A.. c) “Síntesis, caracterización y aplicaciones de materiales poliméricos”, (UTN, Código 25/I047). Período 01/01/2011 – 31/12/2014. Director J.I. Amalvy. d) Proyecto de la Agencia Nacional de Promoción Científico y Tecnológica, PICT 2011 N° 0238 “Materiales poliméricos compuestos, sintéticos y naturales, con aplicaciones en medio am-biente e industria&rdquo...
Proyectos de investigación en los cuales colabora: a) Desarrollo de sistemas polimé... more Proyectos de investigación en los cuales colabora: a) Desarrollo de sistemas poliméricos para formulaciones de pinturas y recubrimientos en base acuosa. Estudios sobre sistemas poliméricos compatibles en medio acuoso, para reducir y/o eliminar el uso de solventes orgánicos (VOC). b) PICT 2008 N° 2218 “Metalofármacos de vanadio y cobre: síntesis, caracterización y activi-dad biológica en cultivos celulares por exposición directa”, Director: Susana B. Etcheverry. 09/2010 – 09-2013 c) “Síntesis, caracterización y aplicaciones de materiales poliméricos”, (UTN, Código 25/I047). Período 01/01/2011 – 31/12/2013. d) Red SPIDER “Statistical Physics in Diverse Realisations”, (IRSES N° 295302). 7mo programa marco de la UE
En la actualidad, existe una tendencia creciente de utilizar polímeros naturales por las caracter... more En la actualidad, existe una tendencia creciente de utilizar polímeros naturales por las características de ser renovables, biocompatibles, biodegradables y en muchos casos económicamente viables en aplicaciones varias. En particular los almidones provenientes de diferentes fuentes han sido empleados para elaborar recubrimientos para alimentos. Sin embargo requieren de la adición de plastificantes para reducir la rigidez y tendencia al agrietado. Una práctica común es la incorporación de glicerol, alcohol polivinílico (PVA) o combinaciones de ellos. La plastificación por glicerol es temporaria y puede migrar hacia el alimento. El PVA, por su parte, es un polímero de amplio uso en la industria por ser no-tóxico, soluble en agua, biocompatible y biodegradable, con resistencia química y alta flexibilidad, así como buenas propiedades de barrera para el oxígeno y los aromas. Sin embargo, la plastificación empleando PVA como único plastificante requiere de la incorporación de cantidades i...
The high doses of sulfadiazine (SDZ), used in synergistic combination with pyrimethamine, are mai... more The high doses of sulfadiazine (SDZ), used in synergistic combination with pyrimethamine, are mainly responsible for severe side effects and discontinuation of toxoplasmosis treatments. In the search for new strategies that improve the efficacy of treatments with reduced doses of SDZ, we have determined the performance of cationic G4 (DG4) and anionic G4.5 (DG4.5) poly(amidoamine) (PAMAM) dendrimers to act as SDZ nanocarriers. Both dendrimers could efficiently load SDZ (SDZ-DG4 and SDZ-DG4.5) up to a ratio of 30 molecules SDZ per dendrimer molecule. The MTT assay on Vero and J774 cells showed no cytotoxicity for DG4.5 and its SDZ complex incubated between 0.03 and 33 microM of dendrimer concentration. On the other hand, DG4 and its SDZ complex resulted cytotoxic when incubated at dendrimer concentrations higher than 3.3 microM. Finally, complexes and empty dendrimers were in vitro tested against Vero cells infected with RH strain of Toxoplasma gondii along 4h of treatment. For SDZ-D...
The development of water-based anticorrosive systems as well as the assessment of its anticorrosi... more The development of water-based anticorrosive systems as well as the assessment of its anticorrosive properties through different conventional tests are discussed in this work. Steel panels coated with different painting systems were subjected to standardized (salt spray, humidity chamber, adhesion, and flexibility) tests. The binder used in this research was prepared in the laboratory by emulsion polymerization of styrene and acrylic monomers. Three ecological pigments were used: two phosphate-based and one prepared in the laboratory using a tannin-based recipe. Two levels of pigment charge were tested. The commonly used zinc tetraoxychromate pigment in solvent-borne coatings was included as reference. It was found that the ecologically friendly formulations tested in this work protect steel against corrosion effectively. The zinc tetraoxychromate pigment was not suitable for the binder used in this work as judged by the inferior corrosion protection of formulations containing it. Possible reasons based on binder-pigment interactions are discussed.
En este trabajo, se presentan los cursos de Español 3 y Español 4 organizados especialmente a ped... more En este trabajo, se presentan los cursos de Español 3 y Español 4 organizados especialmente a pedido de la Universidad de Leiden. De acuerdo con los programas provistos por el Departamento de Español de esta universidad holandesa, se seleccionaron los contenidos gramaticales en relación con los contenidos funcionales. Para ello, se elaboraron actividades que propiciaban las cuatro macrohabilidades-leer, escuchar, hablar y escribir utilizando materiales auténticos que incluían cuestiones culturales relevantes de la Argentina. Se expondrán algunos ejemplos de los materiales utilizados, la metodología con la cual se abordaron y algunos resultados obtenidos en las producciones de los alumnos.
A pH-sensitive blend of polyurethane (PU) and poly(2-(diethyl amino)ethyl methacrylate (PDEA) wit... more A pH-sensitive blend of polyurethane (PU) and poly(2-(diethyl amino)ethyl methacrylate (PDEA) with good film-forming capacity was prepared from the corresponding aqueous dispersions. The polymer matrix was first characterized by using FTIR, DSC, water vapor transmission and water swelling capacity at different pHs. The drug release profile of films was evaluated using a vertical Franz Cell and theophylline as model drug. The water swelling degree increases from 54 to 180% when the pH of the medium is changed from 6 to 2, demonstrating the pH-responsive behavior of the film. The in-vitro release studies indicate that an anomalous transport mechanism governs the theophylline release.
The influence of a tannin pretreatment applied to slightly rusted steel panels on the anticorrosi... more The influence of a tannin pretreatment applied to slightly rusted steel panels on the anticorrosive performance of alkyd paint systems has been investigated using electrochemical impedance spectroscopy (EIS) and open circuit potential measurements. From EIS and corrosion potential data analysis it was found that (1) there is not a significant influence of the tannin pretreatment on the anticorrosive protection level,
Polyurethane/acrylate hybrid composites in a broad range of composition (10, 30, 50, 70 and 90 wt... more Polyurethane/acrylate hybrid composites in a broad range of composition (10, 30, 50, 70 and 90 wt.% of acrylic content), were obtained by emulsion polymerization of acrylic monomers (methyl methacrylate/n-butyl acrylate/acrylic acid mixture) in the presence of preformed polyurethane chains with polymerizable terminal vinyl groups. Blends with the same acrylic content were also prepared by mixing polyurethane and acrylic dispersions. Samples were characterized by SEC, DLS, FTIR, UV, TEM, AFM, SAXS/WAXS and gel fraction content. Mechanical properties, Buccholz and pencil hardness, surface roughness and water contact angle of films were also determined. The effect of the acrylic content on morphology and film properties was also evaluated. Hybrids are crosslinked systems showing changes in the particle and film morphologies with increasing acrylic content. The properties of hybrid films show a non-linear behavior with the increase of the acrylic component, while physical blends exhibit a gradual behavior from PU to AC. FTIR results indicate better acrylic-polyurethane compatibility in hybrid systems than in physical blends. Hybrid composites with up to 70 wt.% of acrylic component are homogeneous by SAXS. On the other hand, AFM results show that blends are phase segregated systems at all composition levels.
This work is part of studies of drying of paints using dynamic speckle interferometry (DSI), a te... more This work is part of studies of drying of paints using dynamic speckle interferometry (DSI), a technique based on the use of laser light. DSI is a non-invasive method that does not disturb the drying process. The sample is illuminated by a laser light from a source and the images corresponding to a phenomenon of interference called speckle are registered. If the surface shows activity, the interference pattern changes in time. Following this evolution, we can analyze the drying process by means of an image-processing algorithms. Therefore, it is possible to determine the temporal evolution of surfaces with different drying times. In this work the application of DSI to follow the drying process of paints with different drying times and drying velocities is presented. Different types of paints applied in different thicknesses of wet film and aerosol spray were analyzed. Quantitative measurements were obtained by analysis of the inertia moment of the co-occurrence matrix. Also, qualitative measurements were obtained by sample activity. A new approach for monitoring simultaneously zones with different drying times is discussed and applied. As in previous work, results were compared with those from conventional techniques such as gravimetric analysis providing a good correlation between both techniques.
The rheological and morphological properties and in vitro theophylline release of tertiary amineb... more The rheological and morphological properties and in vitro theophylline release of tertiary aminebased microgels were evaluated. The testing of such a formulation through in vitro diffusion experiments revealed that the release of theophylline from the microgels was pH-dependent and differs significantly with respect to a nonresponsive gel like scleroglucan (Scl). The microgels were obtained from 2-(diethyl amino) ethylmethacrylate (DEA) in the presence of a bifunctional crosslinker at pH 8-9. As the resulting microgels are pH-responsive and an increase in viscosity from high to low pH range is exhibited, the in vitro release of theophylline as model drug was studied at different pHs of both the matrix and the receptor medium. The release behaviors of PDEA-based microgels were compared to nonresponsive natural gel Scl, studied previously. For microgels, diverse release patterns were found at different acidity conditions. This observation seems to be related to complex diffusion phenomena and the different gel structure obtained for samples prepared at dissimilar pH.
Polyurethane (PU)/acrylate hybrids with different acrylic contents (10, 30, 50, 70, and 90 wt %) ... more Polyurethane (PU)/acrylate hybrids with different acrylic contents (10, 30, 50, 70, and 90 wt %) were prepared by the polymerization of acrylic monomers in the presence of preformed PU chains with polymerizable terminal vinyl groups. Films obtained by the casting of polymer dispersions before and after thermal annealing were characterized by dynamic light scattering, Fourier transform infrared spectroscopy, transmission electron microscopy (TEM), TEM electron energy-loss spectroscopy, differential scanning calorimetry, and gel fraction determination. Small-angle X-ray scattering (SAXS), wide-angle Xray scattering, mechanical properties testing, atomic force microscopy, water contact angle testing, Buchholz hardness testing, and roughness testing of the films were also performed. The effects of the acrylic content and thermal treatment on the structure and properties were determined. TEM showed that a core-shell morphology was formed during polymerization. When the acrylic content increased, smaller particles without core-shell morphologies were observed. TEM energy-loss spectroscopy studies confirmed this observation. Systems with up to 50 wt % acrylic component were homogeneous, as determined by SAXS, before and after thermal annealing. An attempt to incorporate a higher amount of acrylic component led to phase-separated materials with a different morphology and, therefore, different properties. The relationship between the acrylic content and properties did not follow linear behavior. V
The development of glossy topcoat one-pot exterior paint formulations using water-based polyureth... more The development of glossy topcoat one-pot exterior paint formulations using water-based polyurethane/acrylates hybrid binders as well as the assessment of its properties through different conventional tests is discussed in this work. Polyurethane (PU) anionomer having 2-ethoxymethacrylate terminal groups was prepared following a prepolymer mixing process. This prepolymer was chain extended in aqueous solution and after addition of acrylic monomers radical polymerized. Paints were prepared using titanium dioxide as unique pigment. Panels coated with air-dried paints with three pigment to volume concentration (PVC) values were subjected to standardized tests including adhesion, flexibility, gloss and color determination. Accelerated weathering tests were carried out to evaluate changes in properties, especially gloss and color, of painted panels. Solvent-based acrylic and polyurethane paints were included as high gloss quality reference coatings. It was found that air-dried formulations based on hybrid polyurethane/acrylic with up to 50 wt.% of acrylic component, show a gloss as high as 70 and the relative gloss change after accelerated weathering test is lower than the pure solvent-based acrylic and polyurethane paints.
The development of glossy topcoat one-pot exterior paint formulations using water-based polyureth... more The development of glossy topcoat one-pot exterior paint formulations using water-based polyurethane/acrylates hybrid binders as well as the assessment of its properties through different conventional tests is discussed in this work. Polyurethane (PU) anionomer having 2-ethoxymethacrylate terminal groups was prepared following a prepolymer mixing process. This prepolymer was chain extended in aqueous solution and after addition of acrylic monomers radical polymerized. Paints were prepared using titanium dioxide as unique pigment. Panels coated with air-dried paints with three pigment to volume concentration (PVC) values were subjected to standardized tests including adhesion, flexibility, gloss and color determination. Accelerated weathering tests were carried out to evaluate changes in properties, especially gloss and color, of painted panels. Solvent-based acrylic and polyurethane paints were included as high gloss quality reference coatings. It was found that air-dried formulations based on hybrid polyurethane/acrylic with up to 50 wt.% of acrylic component, show a gloss as high as 70 and the relative gloss change after accelerated weathering test is lower than the pure solvent-based acrylic and polyurethane paints.
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