238 research outputs found
Cellulose nanocrystal reinforced acylglycerol-based polyurethane foams
No full textThis work presents the preparation of polyurethane composite foams based on castor oil or modified canola oil as a polyol, and cellulose nanocrystals (CN) as nanofiller (0.10, 0.25, and 0.50 wt% of CN content). The bio-based composites were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), and mechanical properties. The SEM images showed that composite foams had smaller cell sizes and more irregular than those observed for unloaded samples. FTIR revealed that the urethane/urea bond formation was influenced by the incorporation of CN, and was dependent on the polyol used in the formulation. The incorporation of CN did not affect the thermal stability, but the density and mechanical properties changed differently depending on the selected polyol. These results suggested that the acylglycerol structure affects the role of CN in the formulation. Also, the proliferation of MC3T3-E1 preosteoblastic cells showed that the cell viability of polyurethane bionanocomposite foams increased significantly in comparison to the unloaded material.Fil: Gangoiti, Maria Virginia. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Ciencias Biológicas. Laboratorio de Investigación en Osteospatías y Metabolismo Mineral; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Peruzzo, Pablo Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional Arturo Jauretche; Argentin
Effect of food additives on the microstructure, mechanical and water transport properties of polyurethane films
No full textThe objective of this work is to study the effects of common food preservatives (BHT, α-tocopherol, EDTA-Na and potassium sorbate) on the morphological, mechanical and water transport properties of polyurethane (PU) as films or coatings. The influence of these additives on the polymer structure and the polymer-additive interaction was evaluated by using SAXS, FTIR and DSC. The addition of additives results either in the formation of aggregates or modification of the polymer microstructure, depending on the molecular size and nature of additive, i.e. number of polar groups, hydrophilicity, etc. The addition of BHT molecules seems to break the typical hard segments interactions in PUs, leading therefore to a good incorporation of the molecule in the polymer matrix, however, α-tocopherol does not incorporate onto the PU matrix leading to an evident phase separation and not affecting therefore the microrange of heterogeneities of the PU matrix. On the contrary, films doped with EDTA-Na or potassium sorbate showed important changes in both soft and hard segments domains. As consequence, the water transport properties were greatly affected by the incorporation of these food additives in the polymeric matrix. Films with potential antimicrobial or antioxidant activity were obtained, with a moderated decrease in the mechanical properties.Fil: Anbinder, Pablo Sebastián. Universidad Nacional del Centro de la Pcia.de Bs.as.. Centro de Investigaciones En Física E Ingeniería del Centro de la Provincia de Buenos Aires. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigaciones En Física E Ingeniería del Centro de la Provincia de Buenos Aires. Provincia de Buenos Aires. Gobernación. Comision de Invest.científicas. Centro de Investigaciones En Física E Ingeniería del Centro de la Provincia D; ArgentinaFil: Peruzzo, Pablo Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Instituto de Investigaciones Fisico-químicas Teóricas y Aplicadas. Universidad Nacional de la Plata. Facultad de Cs.exactas. Instituto de Investigaciones Fisico-químicas Teóricas y Aplicadas; ArgentinaFil: Amalvy, Javier. Universidad Tecnologica Nacional. Facultad Regional La Plata; Argentin
Encapsulation of Clay Within Polymer Particles in a High Solids Aqueous Dispersion
No full textBy 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 final stable dispersions can have a solids content of up to 50 wt %. Transmission electron microscopy images clearly show the presence of clay platelets inside the polymer colloids, although they are not totally exfoliated. The obtained nanocomposites showed an increase in both the storage modulus in the rubbery state and the water resistance as the clay content increases. The approach presented here might be useful for encapsulating other high-aspect ratio nanofillers.Fil: Reyes, Yury. Universidad del Pais Vasco. POLYMAT; EspañaFil: Peruzzo, Pablo Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad del Pais Vasco. POLYMAT; EspañaFil: Fernández, Mercedes. Universidad del Pais Vasco. POLYMAT; EspañaFil: Paulis, Maria. Universidad del Pais Vasco. POLYMAT; EspañaFil: Leiza, Jose R.. Universidad del Pais Vasco. POLYMAT; Españ
Deflex® brand high impact polyamide aging study in commercial artificial saliva
No full textEste trabajo presenta los resultados de un estudio de envejecimiento natural y acelerado en saliva artificial, de un material para uso odontológico de la marca Deflex® a base de poliamidade alto impacto, según lo establece la norma UNE EN IS0 10993-13 (2009).This work presents the results of the study of natural and accelerated aging in artificial saliva, of a material for dental use of the brand Deflex® based on high impact polyamide, as established by the standard UNE EN IS0 10993-13 (2009).Fil: Peruzzo, Pablo Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Amalvy, Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentin
Surface, thermal, and mechanical properties of composites and nanocomposites of polyurethane/PTFE nanoparticles
No full textFilms from blends of polyurethane and nano-polytetrafluoroethylene aqueous dispersions (PU/nanoPTFE) were prepared, and the effect of the addition of different amounts of PTFE nanoparticles (50 nm) was studied. The changes in the superficial
properties of the films were studied by means of XPS, ATR/FTIR, and contact angle measurements. SEM and TEM results are also included. The contact angle values confirm the surface hydrophobicity of composite films. Even though nanoparticles are present in the bulk, higher concentrations of particles appear at the surface in samples with lower nanoPTFE content (up to 10 wt%), as revealed by XPS. Higher amounts of nanoPTFE particles cause aggregation. The mechanical and thermal properties of composites are also discussed.Fil: Anbinder, Pablo Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional de La Plata; ArgentinaFil: Peruzzo, Pablo Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional de La Plata; ArgentinaFil: de Siervo, Abner. Universidade Estadual de Campinas; BrasilFil: Amalvy, Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Investigación y Desarrollo en Tecnología de Pinturas (i); Argentin
Effect of antioxidant active films on the oxidation of soybean oil monitored by Fourier Transform Infrared Spectroscopy
No full textAn active film prepared from waterborne polyurethane incorporated with different concentrations of butylated hydroxytoluene (BHT) and α-tocopherol was developed, and the films? antioxidant characteristics were studied using soybean oil as food model. The release behavior of additives from such films was studied using isooctane as a simulant fatty food. Antioxidant activity of the films into soybean oil at three experimental conditions was monitored by FTIR spectroscopy. Induction time and the kinetics of the oxidation process were followed using different bands of the FT-IR spectra. Films incorporated with 2 wt.% of BHT or α-tocopherol showed enough antioxidant activity to preclude oil oxidation during 60 days at 60 °C in the dark. The results showed that this type of active films could be used for food preservation as part of a packaging containing oils or oily related products.Fil: Anbinder, Pablo Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional de La Plata; ArgentinaFil: Peruzzo, Pablo Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional de La Plata; ArgentinaFil: Martino, Miriam Nora. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Investigaciones en Criotecnología de Alimentos (i); Argentina. Universidad Nacional de La Plata; ArgentinaFil: Amalvy, Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Investigación y Desarrollo en Tecnología de Pinturas (i); Argentin
Effect of the incorporation of modified silicas onto the final properties of wood adhesives
No full textThe 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 compatibility with the monomer are located inside or close to the polymer particles surface, the silica that presents the lowest compatibility with the monomer is located exclusively on the surface of the polymer particles. This is found to affect the properties of the adhesives as higher tensile strengths are measured in the presence of silicas with good compatibility with the monomer. The reactivity between one of the silica modifiers and the polymer is the key to substantially improve the hydrophobicity and the adhesion of hybrid PVAc based adhesiveFil: Bonnefond, Audrey. Universidad del Pais Vasco; EspañaFil: Reyes, Yury. Universidad del Pais Vasco; EspañaFil: Peruzzo, Pablo Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad del Pais Vasco; EspañaFil: Ronne, Eric. AkzoNobel. Sickla Industriväg; SueciaFil: Fare, Joanna. AkzoNobel. Sickla Industriväg; SueciaFil: Paulis, Maria. Universidad del Pais Vasco; EspañaFil: Leiza, José Ramón. Universidad del Pais Vasco; Españ
Beneficial in-situ incorporation of nanoclay to waterborne PVAc/PVOH dispersion adhesives for wood applications
No full textNanoclay/polyvinyl acetate waterborne adhesives were prepared by using a two-step polymerization process. First, seed polymer particles containing the clay were obtained by batch miniemulsion polymerization. Then, the clay was buried within the particles by the addition of a neat monomer in the second step. The final stable dispersions could have up to 50 wt% of solids content. TEM images clearly showed the presence of clay inside the polymer colloids, although not totally exfoliated. The addition of nanoclay produced adhesives with higher water and heat resistance judged by the water swelling behavior and thermal degradation properties, which was reflected also in their better adhesive performance under wet conditions (D3 tests according to EN204) and high temperatures (WATT91) of the samples containing clay with respect to the pristine dispersions.Fil: Peruzzo, Pablo Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional de La Plata; ArgentinaFil: Bonnefond, Audrey. University of the Basque Country. Kimika Zientzien Fakultatea; EspañaFil: Reyes, Yuri. University of the Basque Country. Kimika Zientzien Fakultatea; EspañaFil: Fernández, Mercedes. University of the Basque Country. Kimika Zientzien Fakultatea; EspañaFil: Fare, Joanna. AkzoNobel; SueciaFil: Ronne, Eric. AkzoNobel; SueciaFil: Paulis, Maria. University of the Basque Country. Kimika Zientzien Fakultatea; EspañaFil: Leiza, José R.. University of the Basque Country. Kimika Zientzien Fakultatea; Españ
Biomodification of acenocoumarol by bifidobacteria
No full textThe increased interest of consumers in probiotic foods requires a deeper knowledge on the possible interactions with drugs, because their pharmacological properties could be modified. In this context, these studies are relevant for drugs such as acenocoumarol, whose dosage must be controlled due to, among other factors, food-drug interactions. Acenocoumarol is an oral anticoagulant with a narrow therapeutic range. The aim of the present research is to evaluate, in vitro, the effect of bifidobacteria on acenocoumarol. The drug was incubated with Bifidobacterium bifidum CIDCA 5310 or Bifidobacterium adolescentis CIDCA 5317 in MRS broth at 37°C for 24 h in anaerobic conditions. The effect of incubation with sterilized spent culture supernatants (SSCS) was also evaluated. Analysis by RP-HPLC showed that both bifidobacterial strains reduced the area of the acenocoumarol peak and two new peaks were evidenced. In addition, a decrease in the intensity of the bands at 1650, 1390 and 1110/cm was observed in the FTIR spectroscopic determinations. Moreover, a new band appeared at 1720/cm. No effect on the drug was observed when incubation was performed with SSCS. The present study showed a significant change in the concentration of the anticoagulant after incubation with bifidobacteria and results are compatible with biomodification of the drug due to enzymatic activity of bifidobacteria.Fil: Fragomeno, Melisa. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Assad, Sabrina Eliana. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Mobili, Pablo. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Peruzzo, Pablo Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Minnaard, Jessica. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Perez, Pablo Fernando. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentin
Nanoarchitectonics based on S-layer proteins: Design of noble metal nanoparticle arrangements and nanostructured materials
No full textNanoarchitectonics based on molecules of biological origin or bio-active components for the creation of hierarchical systems with tailored structures and properties is an area of growing interest. Thus, the S-layer proteins isolated from Bacteria and Archaea emerge as promising building blocks for the design of new structures given their unique characteristics. Due to the presence of well-defined reaction sites in S-layer protein self-assembled structures both in dispersion and on different surfaces, it is possible to use them for the preparation of metallic nanoparticles. This chapter presents themost relevant aspects of S-layer proteins with particular attention to their use through different strategies for the preparation of arrangements of metallic nanoparticles and nanostructured systems containing metallic nanoparticles for various applications.Fil: Bolla, Patricia Araceli. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; ArgentinaFil: Serradell, María de los Ángeles. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Casella, Mónica Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires; ArgentinaFil: Peruzzo, Pablo Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentin
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