scholarly journals PBAT/TPS Composite Films Reinforced with Starch Nanoparticles Produced by Ultrasound

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Normane Mirele Chaves da Silva ◽  
Paulo Romano Cruz Correia ◽  
Janice Izabel Druzian ◽  
Farayde Matta Fakhouri ◽  
Rosana Lopes Lima Fialho ◽  
...  

The objective of the present work was to study the incorporation of starch nanoparticles (SNP) produced by ultrasound in blends of poly(butylene adipate-co-terephthalate) (PBAT) and thermoplastic starch (TPS). The films were produced by extrusion using varying percentages of SNP (1, 2, 3, 4, and 5% w/w). The SNP were prepared in water without the addition of any chemical reagent. The results revealed that ultrasound treatment results in the formation of SNP less than 100 nm in size and of an amorphous character and lower thermal stability and low gelatinization temperature when compared with cassava starch. Scanning electron microscopy (SEM) showed that films presented some starch granules. The relative crystallinity (RC) of films decreases with increasing concentration of SNP. The addition of SNP slightly affected the thermal degradation of the films. The DSC results showed that the addition did not modify the interaction between the different components of the films. Mechanical tests revealed an increase in Young’s modulus (36%) and elongation-at-break (35%) with the incorporation of 1% SNP and this concentration reduced the water vapor permeability (53%) and significantly decreased the water absorption of the films, demonstrating that low concentrations of SNP can be used as reinforcement in a polymeric matrix.

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1606
Author(s):  
Peng Yin ◽  
Jinglong Liu ◽  
Wen Zhou ◽  
Panxin Li

To improve the functional properties of starch-based films, chitin (CH) was prepared from shrimp shell powder and incorporated into corn starch (CS) matrix. Before blending, maleic anhydride (MA) was introduced as a cross-linker. Composite CS/MA-CH films were obtained by casting-evaporation approach. Mechanical property estimation showed that addition of 0–7 wt % MA-CH improved the tensile strength of starch films from 3.89 MPa to 9.32 MPa. Elongation at break of the films decreased with the addition of MA-CH, but the decrease was obviously reduced than previous studies. Morphology analysis revealed that MA-CH homogeneously dispersed in starch matrix and no cracks were found in the CS/MA-CH films. Incorporation of MA-CH decreased the water vapor permeability of starch films. The water uptake of the films was reduced when the dosage of MA-CH was below 5 wt %. Water contact angles of the starch films increased from 22° to 86° with 9 wt % MA-CH incorporation. Besides, the composite films showed better inhibition effect against Escherichia coli and Staphylococcus aureus than pure starch films.


2013 ◽  
Vol 750-752 ◽  
pp. 1582-1585
Author(s):  
Chun Hong Zhang ◽  
Nan Chang ◽  
Chen Li ◽  
Xin Hua Li

Zein was added into wheat gluten (WG) to prepare zein composite films (ZCF) in order to improve the properties of films. The film-forming ability, properties, surface microstructure and infrared spectrum of WG films and ZCF were investigated. The results show that the viscosity of film-forming solutions decrease, and uniformity become worse slightly, after zein added. ZCF are yellow, with metal luster, whose toughness and water retention increase. Compared to the control, the ZCF tensile strength (TS), elongation at break (EB) and resistance of oxygen are increased by 33.2%, 17.2% and 11.25%, and water vapor permeability (WVP) and transparency are decreased by 26.0% and 75.4% respectively. ZCF have better antibacterial properties than WG films. The inhibition effect on escherichia coli and staphylococcus aureus are increased by 36.36% and 32.89% respectively. Hydrogen bond interaction of ZCF become weak, and the surface of ZCF become smooth and evenly.


Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 84
Author(s):  
Sijun Ma ◽  
Yuanrong Zheng ◽  
Ran Zhou ◽  
Ming Ma

Four kinds of edible composite films based on chitosan combined with additional substances (konjac glucomannan, cassava starch, maltodextrin and gelatin) and the addition of lysozyme were prepared and used as packaging materials for Mongolian cheese. The prepared composite films were evaluated using scanning electron microscopy and Fourier transform infrared spectroscopy. The physicochemical properties of all chitosan composite films, including thickness, viscosity, opacity, color, moisture content, water vapor permeability, tensile strength and elongation at break, were measured. The results show that Konjac glucomannan–chitosan composite film presented the strongest mechanical property and highest transparency. The cassava starch–chitosan composite film presented the highest water barrier property. The study on the storage characteristics of Mongolian cheese was evaluated at 4 °C. The results show that the cheese packaging by cassava starch–chitosan composite film presented better treatment performance in maintaining the quality, reducing weight loss and delayering microbial growth.


Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3186
Author(s):  
Emília Csiszár ◽  
Dávid Kun ◽  
Erika Fekete

Composite films were fabricated by using cellulose nanocrystals (CNCs) as reinforcement up to 50 wt% in thermoplastic starch (TPS). Structure and interactions were modified by using different types (glycerol and sorbitol) and different amounts (30 and 40%) of plasticizers. The structure of the composites was characterized by visible spectroscopy, Haze index measurements, and scanning electron microscopy. Tensile properties were determined by tensile testing, and the effect of CNC content on vapor permeability was investigated. Although all composite films are transparent and can hardly be distinguished by human eyes, the addition of CNCs somewhat decreases the transmittance of the films. This can be related to the increased light scattering of the films, which is caused by the aggregation of nanocrystals, leading to the formation of micron-sized particles. Nevertheless, strength is enhanced by CNCs, mostly in the composite series prepared with 30% sorbitol. Additionally, the relatively high water vapor permeability of TPS is considerably decreased by the incorporation of at least 20 wt% CNCs. Reinforcement is determined mostly by the competitive interactions among starch, nanocellulose, and plasticizer molecules. The aging of the films is caused by the additional water uptake from the atmosphere and the retrogradation of starch.


Coatings ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 262 ◽  
Author(s):  
Ying Zhou ◽  
Tonglin Xu ◽  
Yu Zhang ◽  
Chong Zhang ◽  
Zhaoxin Lu ◽  
...  

Incorporating phenolic acids into polysaccharide films improves their physical properties, in turn improving their potential commercial applicability as a preservation material for different foods. This study aimed to develop films from curdlan and tea polyphenols, and determine the effect of their contents on the water vapor permeability (WVP) and mechanical properties (tensile strength and elongation at break) of the films. Different ratios of tea polyphenols were incorporated into the curdlan-based films to improve their properties. The results obtained showed that the tensile strength and elongation at break of films were likely to be significantly decreased by adding tea polyphenols, especially at a content of 0.6%, which resulted in a 50% decrease. Meanwhile, the WVP and moisture content of the films was also decreased. However, a low WVP can prevent moisture loss from food. Other film properties, such as antioxidant efficiency, were also investigated. The results showed that the antioxidant potential of the film can be improved by tea polyphenols. The composite films were also applied to the preservation of chilled meat, which resulted in the shelf life being extended by about 3–5 days. Some properties, such as water resistance and DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical scavenging capacity of the composite film, were improved.


Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1071 ◽  
Author(s):  
Luis Angel Granda ◽  
Helena Oliver-Ortega ◽  
Maria José Fabra ◽  
Quim Tarrés ◽  
Maria Àngels Pèlach ◽  
...  

Nowadays, the interest on nanofibrillated cellulose (CNF) has increased owing to its sustainability and its capacity to improve mechanical and barrier properties of polymeric films. Moreover, this filler shows some drawbacks related with its high capacity to form aggregates, hindering its dispersion in the matrix. In this work, an improved procedure to optimize the dispersability of CNF in a thermoplastic starch was put forward. On the one hand, CNF needs a hydrophilic dispersant to be included in the matrix, and on the other, starch needs a hydrophilic plasticizer to obtain a thermoformable material. Glycerol was used to fulfil both targets at once. CNF was predispersed in the plasticizer before nanofibrillation and later on was included into starch, obtaining thin films. The tensile strength of these CNF–starch composite films was 60% higher than the plain thermoplastic starch at a very low 0.36% w/w percentage of CNF. The films showed a noticeable correlation between water uptake, and temperature and humidity. Regarding permeability, a ca. 55% oxygen and water vapor permeability drop was found by nanofiller loading. The hydrolytic susceptibility of the composite was confirmed, being similar to that of the thermoplastic starch.


2020 ◽  
Vol 9 (2) ◽  
pp. 98-107
Author(s):  
Athoillah Azadi ◽  
◽  
Sugeng Supriyadi ◽  
Heny Herawati ◽  
◽  
...  

A biocomposite system incorporating sago starch and nano-chitosan (SS/NCS) were developed by casting and solvent evaporation method. The purpose of this experiment for characterization of the film based on sago starch (SS) with a variation of the addition of nano-chitosan (0, 2, 4, 6 and 8% by weight starch) and analyze its effect on mechanical properties, thermal properties, and morphological characteristics of mixed film (SS / NCS). Possible intermolecular interactions between SS and NCS were confirmed by Fourier-transform infrared spectroscopy (FTIR) and the reduction of crystallinity in XRD. The experimental data showed that the incorporation of nano-chitosan resulted in an increase in film solubility, tensile strength and elongation at break and a decrease in Young’s modulus. Elongation at break of the (SS/NCS) films increased with increasing of nano-chitosan concentration. The water vapor permeability (WVP) of (SS/NCS) films increased with an increase of chitosan concentration and the same tendency observed for the moisture content. Based on thermogravimetric analysis (TGA), the percentage of nano-chitosan content in starch-based films can increase thermal stability.. Scanning electron microscope (SEM) shows the surface morphology and interface of NCS/SS composite films and suggests sufficient homogenization of starch and chitosan in biodegradable composite films.


MRS Advances ◽  
2016 ◽  
Vol 2 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Eunice Cunha ◽  
Fernando Duarte ◽  
M. Fernanda Proença ◽  
M. Conceição Paiva

ABSTRACTGraphite nanoplates (GnP) have recently attracted attention as an economically viable alternative for the development of functional and structural nanocomposites. The incorporation of GnP into waterborne polyurethane (WPU) with loadings from 0.1 to 10 wt.% was studied. The mechanical properties of the composite films were assessed by tensile testing showing an increase of the Young’s modulus up to 48%. The electrical conductivity increased by 9 orders of magnitude and the water vapor permeability of the composite films decreased 57% for composites containing 5.0 wt.% of GnP.


2000 ◽  
Vol 9 (1) ◽  
pp. 23-35 ◽  
Author(s):  
P. TANADA-PALMU ◽  
H. HELÉN ◽  
L. HYVÖNEN

Edible films from wheat gluten were prepared with various amounts of glycerol as a plasticizer. Water vapor permeability, oxygen permeability, tensile strength and percentage elongation at break at different water activities ( aw ) were measured. Films with low amounts of glycerol had lower water vapor and oxygen permeabilities, higher tensile strength and lower elongation at break. Wheat gluten coatings reduced weight loss during two weeks of storage for cherry tomatoes and sharon fruits compared to uncoated controls. A bilayer film of wheat gluten and beeswax significantly lowered weight loss from coated cheese cubes compared to single layer coating of wheat gluten.;


Author(s):  
Jie Liu ◽  
Yanchun Liu ◽  
Eleanor M. Brown ◽  
Zhengxin Ma ◽  
Cheng-Kung Liu

The leather industry generates considerable amounts of solid waste and raises many environmental concerns during its disposal. The presence of collagen in these wastes provides a potential protein source for the fabrication of bio-based value-added products. Herein, a novel composite film was fabricated by incorporating vegetable-tanned collagen fiber (VCF), a mechanically ground powder-like leather waste, into a chitosan matrix and crosslinked with genipin. The obtained composite film showed a compact structure and the hydrogen bonding interactions were confirmed by FTIR analysis, indicating a good compatibility between chitosan and VCF. The optical properties, water absorption capacity, thermal stability, water vapor permeability and mechanical properties of the composite films were characterized. The incorporation of VCF into chitosan led to significant decreases in opacity and solubility of the films. At the same time, the mechanical properties, water vapor permeability and thermal stability of the films were improved. The composite film exhibited antibacterial activity against food-borne pathogens. Results from this research indicated the potential of the genipin-crosslinked chitosan/VCF composites for applications in antimicrobial packaging. 


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