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

<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>

2016 ◽  
Vol 7 (2) ◽  
pp. 173 ◽  
Author(s):  
Silvio José Souza ◽  
Nicolli Grecco Marchiore ◽  
Marcella Vitória Galindo ◽  
Fabio Yamashita ◽  
Marianne Ayumi Shirai

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.


2014 ◽  
Vol 884-885 ◽  
pp. 481-484 ◽  
Author(s):  
Yan Wu ◽  
Ming Wei Yuan ◽  
Ji Yi Yang ◽  
Yu Yue Qin ◽  
Ming Long Yuan ◽  
...  

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.


2016 ◽  
Vol 36 (2) ◽  
pp. 181-188 ◽  
Author(s):  
Aleksandra Buzarovska ◽  
Gordana Bogoeva-Gaceva ◽  
Radek Fajgar

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.


2014 ◽  
Vol 900 ◽  
pp. 320-323
Author(s):  
Ming Wei Yuan ◽  
Yan Wu ◽  
Yu Yue Qin ◽  
Ming Long Yuan ◽  
Hong Li Li

In this work a preliminary study on the physical properties and antimicrobial activity of environmentally friendly active films to be produced is presented. Chitosan (CH), which has antimicrobial effect on many food pathogens, was coated as antimicrobial agent into composite poly (lactic acid)/poly (ε-caprolactone)(PLA-PCL) films. Antimicrobial active films based on PLA-PCL were prepared by coating five different chitosan concentrations: 0, 2, 4, 6 and 8 %(w/w). The mechanical characterization, water vapor permeability (WVP), and antimicrobial activity of composite PLA-PCL film coating with chitosan were carried out. The mechanical characterization, water vapor permeability of composite PLA-PCL films coating with chitosan was uninfluenced. Antimicrobial activities of films were tested against Staphylococcus aurous, Escherichia coli, Bacillus subtilis, Listeria, Salmonella. The antimicrobial activity of films were significantly increase with the chitosan concentration. The results of this work suggest that chitosan coated composite PLA-PCL films have a prospectively potential in antimicrobial activity food packaging.


Coatings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 574 ◽  
Author(s):  
Rosa Turco ◽  
Rodrigo Ortega-Toro ◽  
Riccardo Tesser ◽  
Salvatore Mallardo ◽  
Sofia Collazo-Bigliardi ◽  
...  

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.


Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 158
Author(s):  
Yao Dou ◽  
Liguang Zhang ◽  
Buning Zhang ◽  
Ming He ◽  
Weimei Shi ◽  
...  

The development of edible films based on the natural biopolymer feather keratin (FK) from poultry feathers is of great interest to food packaging. Edible dialdehyde carboxymethyl cellulose (DCMC) crosslinked FK films plasticized with glycerol were prepared by a casting method. The effect of DCMC crosslinking on the microstructure, light transmission, aggregate structure, tensile properties, water resistance and water vapor barrier were investigated. The results indicated the formation of both covalent and hydrogen bonding between FK and DCMC to form amorphous FK/DCMC films with good UV-barrier properties and transmittance. However, with increasing DCMC content, a decrease in tensile strength of the FK films indicated that plasticization, induced by hydrophilic properties of the DCMC, partly offset the crosslinking effect. Reduction in the moisture content, solubility and water vapor permeability indicated that DCMC crosslinking slightly reduced the moisture sensitivity of the FK films. Thus, DCMC crosslinking increased the potential viability of the FK films for food packaging applications, offering a value-added product.


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4910 ◽  
Author(s):  
Alejandro Aragón-Gutierrez ◽  
Marina P. Arrieta ◽  
Mar López-González ◽  
Marta Fernández-García ◽  
Daniel López

Bionanocomposites based on poly (lactic acid) (PLA) and silica aerogel (SiA) were developed by means of melt extrusion process. PLA-SiA composite films were plasticized with 15 wt.% of acetyl (tributyl citrate) (ATBC) to facilitate the PLA processability as well as to attain flexible polymeric formulations for films for food packaging purposes. Meanwhile, SiA was added in four different proportions (0.5, 1, 3 and 5 wt.%) to evaluate the ability of SiA to improve the thermal, mechanical, and barrier performance of the bionanocomposites. The mechanical performance, thermal stability as well as the barrier properties against different gases (carbon dioxide, nitrogen, and oxygen) of the bionanocomposites were evaluated. It was observed that the addition of 3 wt.% of SiA to the plasticized PLA-ATBC matrix showed simultaneously an improvement on the thermal stability as well as the mechanical and barrier performance of films. Finally, PLA-SiA film formulations were disintegrated in compost at the lab-scale level. The combination of ATBC and SiA sped up the disintegration of PLA matrix. Thus, the bionanocomposites produced here show great potential as sustainable polymeric formulations with interest in the food packaging sector.


2014 ◽  
Vol 26 (19) ◽  
pp. 5459-5466 ◽  
Author(s):  
Federico Carosio ◽  
Samuele Colonna ◽  
Alberto Fina ◽  
Gaulthier Rydzek ◽  
Joseph Hemmerlé ◽  
...  

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 927
Author(s):  
Yuelong Zhao ◽  
Hui Sun ◽  
Biao Yang ◽  
Baomin Fan ◽  
Huijuan Zhang ◽  
...  

Hemicellulose is a kind of biopolymer with abundant resources and excellent biodegradability. Owing to its large number of polar hydroxyls, hemicellulose has a good barrier performance to nonpolar oxygen, making this biopolymer promising as food packaging material. Hydrophilic hydroxyls also make the polymer prone to water absorption, resulting in less satisfied strength especially under humid conditions. Thus, preparation of hemicellulose film with enhanced oxygen and water vapor barrier ability, as well as mechanical strength is still sought after. Herein, sodium trimetaphosphate (STMP) was used as esterification agent to form a crosslinked structure with hemicellulose through esterification reaction to render improved barrier performance by reducing the distance between molecular chains. The thus modified hemicellulose film achieved an oxygen permeability and water vapor permeability of 3.72 cm3 × μm × m−2 × d-1 × kPa−1 and 2.85 × 10−10 × g × m−1 × s−1 × Pa−1, respectively, at the lowest esterification agent addition of 10%. The crosslinked structure also brought good mechanical and thermal properties, with the tensile strength reaching 30 MPa, which is 118% higher than that of the hemicellulose film. Preliminary test of its application in apple preservation showed that the barrier film obtained can effectively slow down the oxidation and dehydration of apples, showing the prospect of application in the field of food packaging.


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