PLA-fMWCNT Bionanofilms with High Modulus and Great Properties to Apply in Packaging and Biomedicine

Physicochemical properties of films based on PLA and reinforced with functionalized carbon nanotubes (fMWCNT), was investigated. The filler was functionalized in order to achieve its good dispersion in the matrix. Fenton reaction was carried out and subsequently a reaction with thionyl chloride and with triethylene glycol was performed. Excellent dispersion of the filler in the PLA matrix was observed for composites with filler concentrations till 0.10 wt%. Nanocomposites showed an important increase in the Young's modulus (almost 50%) and cristallinity till 20% when carbon nanotubes were added. UV-Vis spectra indicated that all the films are transparent in the UV-visible range.Fil: González Seligra, Paula Fabiana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física. Laboratorio de Polímeros y Materiales Compuestos; ArgentinaFil: Lamanna, Melisa Elsa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física. Laboratorio de Polímeros y Materiales Compuestos; ArgentinaFil: Fama, Lucia Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física. Laboratorio de Polímeros y Materiales Compuestos; Argentin

Biodegradable and non-retrogradable eco-films based onstarch?glycerol with citric acid as crosslinking agent

Biodegradable and non-retrogradable starch-glycerol based films were obtained using citric acid (CA) as crosslinking agent at 75 °C. This material allowed decreasing water vapor permeability (WVP) more than 35%, remained amorphous for at least 45 days as a result of the network formed by the CA that avoided starch retrogradation and maintained the degradability in compost, occurring only six days after the films without citric acid. A simulation of the gelatinization process of starch-glycerol with and without CA, using a differential thermal analysis device, showed that the system with CA completed the gelatinization 5 °C before than the other and, CA first reacted with glycerol and then starch-glycerol-CA reaction occurred. The temperature at which the gelatinization process was carried out was critical to obtain the best results. An increase of gelatinization process temperature at 85 °C in system with CA, led to a worsening on WVP and its integrity after a swelling process with dimethylsulphoxide (DMSO), compared to the films processed at 75 °C.Fil: Gonzales Seligra, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Medina Jaramillo, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; ArgentinaFil: Fama, Lucia Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Goyanes, Silvia Nair. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentin

Physicochemical and functional properties of native and modified by crosslinking, dark-cush-cush yam (Dioscorea trifida) and cassava (Manihot esculenta) starch

Cush-cush yam (Dioscorea trifida), is a sub-utilized tropical crop, rich in starch, which grown in tropical areas. The exploitation of its starch has great potential. The objectives of this research was to modify starch isolated from dark-cush-cush yam, which grown in the Venezuelan Amazonian, and commercial cassava starch, by cross-linking, in order to characterize and compare them with their native counterparts. The results showed that differences in the amylose content affected the composition, structure and functional properties of both starches. The degree of substitution (DS) was more significant in the cush-cush starch yam than that of the cassava starch, even if both were within the ranges allowed by the FDA. The granular size of cassava starch was slightly changed by modification. The rheological properties also changed, increasing the viscosity peak, breakdown, consistency and setback. Finally, that modification method conferred great stability to the starches gelatinization.Fil: Gutiérrez, Tomy J.. Universidad Central de Venezuela; VenezuelaFil: Pérez, Elevina. Universidad Central de Venezuela; VenezuelaFil: Guzmán, Romel. Universidad Central de Venezuela; VenezuelaFil: Tapia, María Soledad. Universidad Central de Venezuela; VenezuelaFil: Fama, Lucia Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentin

Effect of yerba mate extract on the performance of starch films obtained by extrusion and compression molding as active and smart packaging

Native or hydrolyzed starch and yerba mate extract (10 wt.% or 20 wt.%) films prepared by extrusion and compression molding were investigated. Native starch material (TPNS) exhibited lower water vapor permeability and higher Young's Modulus (E) compared to hydrolyzed starch matrix (TPHS) but decreases in strain at break (εb) and toughness (T). The incorporation of 10 wt.% of extract in TPNS led to greater E and εb and it resulted the most hydrophobic material. Conversely, TPHS with 20 wt.% of additive resulted the film with the highest εb and T, indicating a plasticizing effect of the extract in this concentration and system. All materials disintegrated after 10 weeks of burial, contributing to waste reduction. Biofilms containing yerba mate extract showed antioxidant activity and color changes in different pH, indicating their promising role as active and smart packaging for food, in accordance with the new trends for biodegradable and functional packaging.Fil: Ceballos, Rocío Lais. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Ochoa Yepes, Oswaldo Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Goyanes, Silvia Nair. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Bernal, Celina Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; ArgentinaFil: Fama, Lucia Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentin

Influence of Different Commercial Modified Cassava Starches on the Physicochemical Properties of Thermoplastic Edible Films Obtained by Flat‐die Extrusion

Starch constitutes a promising resource for biodegradable packaging, but it presents several processing drawbacks when using conventional industrial equipment, such as flat-die extrusion. This work demonstrates that the replacement of native cassava starch (NS) with commercial hydrolyzed (HS) or carboxymethyl (CMS) starches diminishes the amount of energy required to process starch granules into thermoplastic films by extrusion. Homogeneous films with starch-glycerol interaction improvements are obtained when using HS or CMS instead of NS. HS films exhibit the lowest crystallinity and the highest susceptibility to water among the studied systems. Likewise, CMS films maximize Vh crystalline structure fraction and present higher Young's modulus and stress at break, and lower water vapor permeability values. In order to combine the positive properties and to overcome the limitations of each modified starch, blend films from HS:CMS (50:50 wt%) are also developed and investigated. Phase separation is observed in this system, and there are no improvements in the overall properties. The results of this investigation show that employing commercial CMS, even in very low carboxymethylation degree represents a successful strategy to improve mechanical and barrier properties of flat-die extruded films, while HS can be used to obtain water-soluble films for specific applications.Fil: Guz, Lucas Martín. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: González Seligra, Paula Fabiana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Ochoa Yepes, Oswaldo Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Estevez Areco, Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Fama, Lucia Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Goyanes, Silvia Nair. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentin

Mechanical properties of tapioca starch edible films containing sorbates

The effect of sorbate present on mechanical properties of edible films prepared with suspensions of tapioca starch containing glycerol, was studied. Films were prepared by casting the systems after gelatinization. The storage modulus (E′) and the tangent of the phase angle (tan δ) of the film pieces were determined with a Dynamic Mechanical Thermal Analyzer along 8 weeks of storage at a relative humidity (RH) of 57.5% and at 25°C. Stress-strain behavior along quasi-static tests was also analysed using the same device. Results obtained showed that sorbate incorporation resulted in a decrease (≅75%) of E′ and an increase (≅200%) of tan δ after 2 weeks of storage. Antimicrobial presence also affected film performance along storage: it showed a continuous decrease of tan δ along 8 weeks storage as well as an increase in the tendency to rupture with time. Films without sorbate showed an increase of tan δ along 4 weeks and they presented rupture for all storage periods studied. Aging of starch, characteristics of the network as well as sorbate destruction along storage, are responsible for the changes observed in mechanical properties of the film along 8 weeks. © 2004 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.Fil: Fama, Lucia Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Rojas, Ana Maria Luisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Goyanes, Silvia Nair. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Gerschenson, Lia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentin

Physicochemical, antimicrobial and mechanical properties of thermoplastic materials based on biopolymers with application in the food industry

Currently, there is great interest in the study of new ecological technologies searching a harmonious lifestyle with the environment. In this sense, numerous investigations on thermoplastic materials have been conducted as a significant alternative due to their promising applications. In this regard, thermoplastics materials from different biodegradable and edible polymer sources, which can be used in food packaging, films or coatings, have been evaluated as an alternative to replace synthetic materials to contribute to environmental pollution. The aim of this chapter was to study the physico-chemical, mechanical and structural properties of biopolymer films for use in the food industry. In this chapter, different components used for the production of biodegradable and edible coatings: biopolymers, plasticizers, antimicrobials and antioxidants are reviewed.Fil: Álvarez, Kelvia. Universidad Central de Venezuela; VenezuelaFil: Fama, Lucia Mercedes. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física. Laboratorio de Polímeros y Materiales Compuestos; ArgentinaFil: Gutiérrez Carmona, Tomy José. Universidad Central de Venezuela; Venezuela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

Influence of green tea and basil extracts on cassava starch based films as assessed by thermal degradation, crystalline structure, and mechanical properties

Natural extracts are investigated as plasticizers of starch?glycerol biobased films for food coating applications. For this purpose, films with cassava starch, glycerol, and distilled water with and without green tea or basil extracts are obtained by solvent casting. The plasticizing effect of the extracts is confirmed from the films crystalline structure, thermal degradation behavior, glass transition temperature, and tensile properties. Increased mobility of starch chains is the result of a strong interaction between extract components and starch molecules. The Kohlrausch?Williams?Watts (KWW) theoretical modeling, used for the first time to determine the effect of antioxidant components in starch films, also confirms the plasticizing effect of either green tea or basil extracts. In addition, the original luminosity of the starch film is not compromised by the incorporation of the extracts. Moreover, a delay in the starch retrogradation is achieved, making the film more durable and hence, very promising to be used as food coating.Fil: Medina Jaramillo, Carolina. Universidad Pedagógica y Tecnológica de Colombia; Colombia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Bernal, Celina Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; ArgentinaFil: Fama, Lucia Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentin

Starch-vegetable fibre composites to protect food products

The influence of wheat bran content in biodegradable composites based on cassava starch and containing glycerol and potassium sorbate were studied. Films were produced by casting and three different fractions of wheat bran fibre were used: 1.5 mg, 13.5 mg and 27.1 mg/g of matrix. It was observed that the addition of wheat bran, which contains 40 g of water insoluble fibre per 100 g of bran, shifted the glycerol-rich phase glass transition temperature toward higher temperatures, broadening and diminishing in intensity the peak associated with this relaxation. This effect suggests that the presence of fibre led to an enhancement in the glycerol dispersion. At room temperature, an increase in fibre content did not affect density of the matrix but caused the increase of the storage modulus and the decrease of loss tangent, moisture content and water vapor permeability. Besides, the addition of fibres led to the increase of the yellow index. The improvement in water vapor barrier properties jointly with the enhancement of mechanical properties when fibre was present, lead to the idea that the composite developed can be used to protect food and extend its shelf life. © 2008 Elsevier Ltd. All rights reserved.Fil: Fama, Lucia Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Gerschenson, Lia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; ArgentinaFil: Goyanes, Silvia Nair. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentin

Promising PLA-functionalized MWCNT composites to use in nanotechnology

Films based on polylactic acid (PLA) reinforced with multi-walled carbon nanotubes (MWCNT) were developed after using an excellent methodology to ensure an optimum dispersion of the filler in the matrix. The functionalization of MWCNT was carried out through a Fenton reaction to generate hydroxyl (OH) and carboxyl (COOH) groups on their walls. After that, COOH groups were lengthened by reacting with thionyl chloride and then with triethylene glycol to achieve a terminal OH distanced from the wall of the MWCNT. Nanocomposites based on PLA containing different concentrations of functionalized filler (fMWCNT: 0.026 wt%, 0.10 wt% and 0.18 wt%) were prepared by casting. The influence of filler concentration was investigated using some techniques such as scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), water vapor permeability (WVP) and uniaxial tensile mechanical properties. Excellent dispersion of fMWCNT was observed suggesting that the technique of functionalization used was appropriate. All nanocomposites presented great stability, allowing them to be processed to temperatures reaching 300 ºC. Furthermore, an increasing trend of ultimate tensile strength (u) up to 20 % and a decrease of WVP around 40 % with the addition of only 0.10 wt% of fMWCNT were obtained. Considering these results, the new biodegradable nanocomposites developed in this work could be very promising to replace synthetic plastics that currently are used in different areas such as nanotechnology, packaging and biomedicine.Fil: Gonzales Seligra, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física. Laboratorio de Polímeros y Materiales Compuestos; ArgentinaFil: Lamanna, Melisa Elsa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física. Laboratorio de Polímeros y Materiales Compuestos; ArgentinaFil: Fama, Lucia Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física. Laboratorio de Polímeros y Materiales Compuestos; Argentin