scholarly journals Production of starch/poly(lactic acid) sheets containing citric acid and tributyl citrate

2016 ◽  
Vol 7 (2) ◽  
pp. 173 ◽  
Author(s):  
Silvio José Souza ◽  
Nicolli Grecco Marchiore ◽  
Marcella Vitória Galindo ◽  
Fabio Yamashita ◽  
Marianne Ayumi Shirai
Keyword(s):  
Lactic Acid ◽  
Water Vapor ◽  
Citric Acid ◽  
Water Vapor Permeability ◽  
Barrier Properties ◽  
Thermoplastic Starch ◽  
Poly Lactic Acid ◽  
Vapor Permeability ◽  
Water Vapor Barrier

In this work thermoplastic starch and poly(lactic acid) (PLA) sheets added of tributyl citrate (TBC) and citric acid was produced by flat extrusion (calendaring-extrusion). The incorporation of TBC and citric acid reduced the rigidity, increased the water vapor permeability (WVP) and density of the sheets. This occurred probably because these compounds acted as plasticizer for PLA and starch. Thus, it was possible to conclude that it was possible to produce starch and PLA blended sheets by extrusion, but studies are still required to find the appropriate concentration of TBC and citric acid that does not significantly impair the water vapor barrier properties.

scholarly journals Effect of chitosan addition in starch and poly(lactic acid) sheets produced by extrusion

2015 ◽  
Vol 6 (1) ◽  
pp. 80
Author(s):  
Matheus Luz Alberti ◽  
Sílvio José De Souza ◽  
Heliberto Gonçalves ◽  
Fabio Yamashita ◽  
Marianne Ayumi Shirai
Keyword(s):  
Lactic Acid ◽  
Water Vapor ◽  
Food Packaging ◽  
Water Vapor Permeability ◽  
Barrier Properties ◽  
Extrusion Process ◽  
Pilot Scale ◽  
Poly Lactic Acid ◽  
Vapor Permeability ◽  
Water Vapor Barrier

<p>The use of blends containing biodegradable polymers like starch and poly (lactic acid) (PLA) has gained considerable attention, especially for the food packaging production. Current research has also highlighted the use of chitosan because their antimicrobial activity, biodegradability and applicability in the production of active biodegradable food packaging. The objective of this work was to produce cassava starch and PLA sheets incorporated with chitosan by flat extrusion process (calendering-extrusion), and evaluate the mechanical, water vapor barrier and microstructural properties. In order to simplify the obtainment of the material reducing processing steps, all components of the blend were homogenized in one step extrusion The incorporation of chitosan in the starch/PLA sheets decreased significantly the tensile strength, Young's modulus, elongation at break and density. In addition, the scanning electron microscopy images showed the formation of non-homogeneous mixtures with the presence of pores between the blend compounds, and this fact affected the water vapor barrier properties increasing water vapor permeability, solubility and diffusion coefficients. It was possible to conclude that although the incorporation of chitosan to the starch/PLA sheets has not contributed to obtain materials with suitable properties, it was able to produce them by calendering-extrusion process in pilot scale. Studies about chitosan incorporation in starch and PLA sheets still needed.</p><p>&nbsp;</p><p>DOI: 10.14685/rebrapa.v6i1.208</p><p>&nbsp;</p>

Effect of the talc filler on structural, water vapor barrier and mechanical properties of poly(lactic acid) composites

2016 ◽  
Vol 36 (2) ◽  
pp. 181-188 ◽  
Author(s):  
Aleksandra Buzarovska ◽  
Gordana Bogoeva-Gaceva ◽  
Radek Fajgar
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Water Vapor ◽  
Composite Films ◽  
Water Vapor Permeability ◽  
Barrier Properties ◽  
Poly Lactic Acid ◽  
Vapor Permeability ◽  
Scanning Calorimetry ◽  
Structural Water

Abstract Poly(lactic acid) (PLA) based composite films with different content of talc (5–15 wt%) were prepared by the solvent casting method. The effect of talc on morphological, structural, thermal, barrier and mechanical properties of neat PLA was investigated. The PLA/talc composites revealed a polymorphic crystalline structure, as demonstrated by X-ray diffraction (XRD) study and differential scanning calorimetry (DSC) analysis. The PLA/talc composites also exhibited significantly improved barrier properties (up to 55% compared to neat PLA), as shown by water vapor permeability (WVP) tests. The puncture measurements showed improved mechanical properties at lower content of talc (up to 5 wt%), and increased brittleness of the PLA/talc composite films at higher talc concentrations.

scholarly journals Poly (Lactic Acid)/Thermoplastic Starch Films: Effect of Cardoon Seed Epoxidized Oil on Their Chemicophysical, Mechanical, and Barrier Properties

Coatings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 574 ◽  
Author(s):  
Rosa Turco ◽  
Rodrigo Ortega-Toro ◽  
Riccardo Tesser ◽  
Salvatore Mallardo ◽  
Sofia Collazo-Bigliardi ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Water Vapor Permeability ◽  
Barrier Properties ◽  
Thermoplastic Starch ◽  
Extrusion Process ◽  
Light Transmittance ◽  
Poly Lactic Acid ◽  
Vapor Permeability ◽  
Physical Interaction ◽  
Scanning Calorimetry

In this work, biodegradable films based on poly (lactic acid) (PLA) and corn thermoplastic starch (TPS), additivated with epoxidized cardoon oil plasticizer (ECO) at 3% by weight with respect to PLA mass fraction, were prepared by melt extrusion process and compression molding. The effect of ECO on structural, thermal, mechanical, barrier, and spectral optical properties of the films was investigated. Spectroscopic analysis evidenced the development of physical interaction between oil and polymers, mainly PLA. In addition, no oil migration occurrence was detected after six months of film preparation, as evidenced by oil mass evaluation by precipitation as well as by 1H-NMR methods, thus highlighting the good inclusion of oil inside the polymeric network. The plasticizing action of the oil induced a lean improvement of the interfacial adhesion between hydrophobic PLA and hydrophilic TPS, particularly accentuated in PLA80_ECO composition, as evidenced by morphological analysis of blend fracture surfaces. TGA data underlined that, differently from TPS-based films, PLA-based systems followed one degradative thermal profile suggesting a slight compatibilization effect of epoxidized oil in these films. The shifting of Tg values, by differential scanning calorimetry (DSC) analysis, indicated a weak miscibility at molecular level. Generally, in the investigated blends, the phase separation between PLA and TPS polymers was responsible for the mechanical properties failing; in particular, the tensile strength evidenced a negative deviation from the rule of mixtures, particularly marked in TPS-based blends, where no physical entanglements occurred between the polymers since their immiscibility even in presence of ECO. The epoxidized oil strongly improved the barrier properties (water vapor permeability (WVP) and oxygen permeability (O2P)) of all the films, likely developing a physical barrier to water and oxygen diffusion and solubilization. With respect to neat PLA, PL80 and PL80_ECO films evidenced the improvement of surface wettability, due to the presence of polar groups both in TPS (hydroxyl residues) and in epoxidized oil (oxirane rings). Finally, following to the conditioning in climatic chamber at T = 25 °C and RH = 50%, PLA80 film became opaque due to TPS water absorption, causing a light transmittance decreasing, as evidenced by spectral optical analysis.

Physical Properties and Antimicrobial Activity of a Poly(Lactic Acid)/Poly(Trimethylene Carbonate) Film Incorporated with Thymol

2014 ◽  
Vol 884-885 ◽  
pp. 481-484 ◽  
Author(s):  
Yan Wu ◽  
Ming Wei Yuan ◽  
Ji Yi Yang ◽  
Yu Yue Qin ◽  
Ming Long Yuan ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Lactic Acid ◽  
Water Vapor ◽  
Composite Film ◽  
Food Packaging ◽  
Water Vapor Permeability ◽  
Antimicrobial Activities ◽  
Poly Lactic Acid ◽  
Vapor Permeability ◽  
Trimethylene Carbonate

Thymol (TH), which has antimicrobial effect on many food pathogens, was incorporated as antimicrobial agent into composite poly (lactic acid)/poly (trimethylene carbonate)(PLA-PTMC) films. Antimicrobial active films based on PLA-PTMC were prepared by incorporating thymol at five different concentrations: 0, 3, 6, 9 and 12 %(w/w). The mechanical characterization, water vapor permeability (WVP), and antimicrobial activity of all formulations composite film were carried out. A decrease in elastic modulus was obtained for the active composite film compared with neat PLA-PTMC film. The presence of thymol decreased water vapor permeability, with a significant antimicrobial activity. Antimicrobial activities of films were tested against Escherichia coli, Staphylococcus aurous, Listeria, Bacillus subtilis, and Salmonella. Increasing amount of the thymol in the film caused a significant increase in inhibitory zones. These results suggest that thymol incorporated PLA-PTMC films have a prospectively potential in antimicrobial food packaging.

scholarly journals Efficient Gas and Water Vapor Barrier Properties of Thin Poly(lactic acid) Packaging Films: Functionalization with Moisture Resistant Nafion and Clay Multilayers

2014 ◽  
Vol 26 (19) ◽  
pp. 5459-5466 ◽  
Author(s):  
Federico Carosio ◽  
Samuele Colonna ◽  
Alberto Fina ◽  
Gaulthier Rydzek ◽  
Joseph Hemmerlé ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Water Vapor ◽  
Barrier Properties ◽  
Poly Lactic Acid ◽  
Packaging Films ◽  
Water Vapor Barrier ◽  
Moisture Resistant

scholarly journals Reducing Water Vapor Permeability of Poly(lactic acid) Film and Bottle through Layer-by-Layer Deposition of Green-Processed Cellulose Nanocrystals and Chitosan

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Katalin Halász ◽  
Yanin Hosakun ◽  
Levente Csóka
Keyword(s):  
Lactic Acid ◽  
Cellulose Nanocrystals ◽  
Self Assembly ◽  
Water Vapor Permeability ◽  
Barrier Properties ◽  
Poly Lactic Acid ◽  
Vapor Permeability ◽  
Layer By Layer ◽  
Barrier Coating ◽  
Assembly Technique

Layer-by-layer electrostatic self-assembly technique was applied to improve the barrier properties of poly(lactic acid) (PLA) films and bottles. The LbL process was carried out by the alternate adsorption of chitosan (CH) (polycation) and cellulose nanocrystals (CNC) produced via ultrasonic treatment. Four bilayers (on each side) of chitosan and cellulose nanocrystals caused 29 and 26% improvement in barrier properties in case of films and bottles, respectively. According to the results the LbL process with CH and CNC offered a transparent “green” barrier coating on PLA substrates.

Crystallization behavior and water vapor permeability of poly(lactic acid) nanocomposite under oscillatory shear

2015 ◽  
Vol 132 (30) ◽  
pp. n/a-n/a ◽  
Author(s):  
Zhongbin Xu ◽  
Liangyao Su ◽  
Shichao Jiang ◽  
Wei Gu ◽  
Mao Peng ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Water Vapor ◽  
Crystallization Behavior ◽  
Water Vapor Permeability ◽  
Oscillatory Shear ◽  
Poly Lactic Acid ◽  
Vapor Permeability

scholarly journals Alginate-Edible Coatings for Application on Wild Andean Blueberries (Vaccinium meridionale Swartz): Effect of the Addition of Nanofibrils Isolated from Cocoa By-Products

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 824
Author(s):  
Carolina Medina-Jaramillo ◽  
Carmen Quintero-Pimiento ◽  
Catalina Gómez-Hoyos ◽  
Robin Zuluaga-Gallego ◽  
Alex López-Córdoba
Keyword(s):  
Water Vapor ◽  
Water Vapor Permeability ◽  
Barrier Properties ◽  
Vapor Permeability ◽  
Edible Coatings ◽  
Refrigerated Storage ◽  
Water Vapor Barrier ◽  
Postharvest Management ◽  
Wild Blueberry ◽  
By Products

Edible coatings and films are appealing strategies for the postharvest management of blueberries. In the current work, alginate and alginate/cellulose nanofibril (CNF) edible coatings crosslinked with calcium chloride were developed for application on Andean blueberry (a promissory wild blueberry). Cocoa by-products were valorized through the isolation of their CNFs, and these were incorporated in the edible coatings. Edible coating formulations were based on blends of alginate (2% w/v), CNFs (0%, 0.1%, or 0.3%), glycerol, and water. In addition, stand-alone films were prepared, and their light and water vapor barrier properties were studied before applying the coating on the fruit surface. The results show that the addition of CNFs caused a significant decrease in the transparency and the water vapor permeability of the alginate films. After applying on the Andean blueberry fruits, the alginate and alginate/CNF coatings enhanced the appearance and the firmness of the fruits. Moreover, they significantly reduced the respiration rate and the water loss of the Andean blueberries throughout the 21 days of refrigerated storage. Alginate and alginate/CNFs coatings may be considered a useful alternative for the delay of the postharvest deterioration of Andean blueberries.

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