Mechanical and Water Barrier Properties of Zein–Corn Starch Composite Films as Affected by Gallic Acid Treatment

2016 ◽  
Vol 12 (8) ◽  
pp. 773-781 ◽  
Author(s):  
Kingsley Masamba ◽  
Yue Li ◽  
Hafiz Rizwan Sharif ◽  
Jianguo Ma ◽  
Fang Zhong

Abstract The effect of gallic acid treatment on mechanical and water barrier properties in zein and zein–corn starch composite films was investigated. Four concentrations of corn starch (5 %, 10 %, 15 %, 20 %) were used in composite films making a final solid concentration of 6 % (w/v) in the film forming solution. One composite film containing 10 % corn starch was also prepared in absence of gallic acid for comparison purpose. Gallic acid treatment improved tensile strength (TS) and water vapor permeability (WVP) while solubility was increased in control zein films. On the other hand, gallic acid treatment significantly (p < 0.05) reduced TS and increased WVP in zein–corn starch composite films. Interestingly, mechanical and water barrier properties of composite films prepared in absence of gallic acid were comparatively better than gallic acid treated composite films. These findings provided useful insights in how each individual hydrocolloid in the composite film was differently affected by gallic acid treatment.

2021 ◽  
pp. 089270572110075
Author(s):  
Kajal Mishra ◽  
Shishir Sinha

The present work focuses on surface functionalization, characterization, biodegradability and barrier properties of MOSF as a practicable reinforcement in PVA matrix. Film-forming dispersions at different concentrations of alkali and acid treatments were casted at room temperature. The effect of surface modifications on the developed film’s compositional, physical, mechanical, biodegradability and barrier properties were analyzed. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Atomic force microscopy (AFM) were used to describe the functional composition, formation and surface morphology of the film. The 5% acid treated film significantly increases the tensile strength (33.69 MPa) and flexural strength (56.612 MPa), which was close to the frequently used LDPE and HDPE package films. Composite films were moisture absorptive but simultaneously capable to maintain uniformity and composition upon modifications. Lower water vapor permeability (1.42 × 10−10gs−1 m−1 Pa−1), eminent biodegradability proved the suitability of composite film for various packaging applications.


2012 ◽  
Vol 476-478 ◽  
pp. 2100-2104 ◽  
Author(s):  
Jian Jun Yan ◽  
Zheng Li ◽  
Jian Fei Zhang ◽  
Chang Sheng Qiao

In the paper, preparation and properties of pullulan composite films were studied. Several kinds of materials (glass, iron, steel, propene polymer and polyvinyl chloride plates) were chosen for preparing films. The results showed that the steel plate was the most suitable material for preparing film. The tensile strength of pullulan film was significantly reduced when the drying temperature was higher than 50°C. The time of dissolution observably decreased, whereas water vapor permeability increased with increasing drying temperature. Pullulan film has higher tensile strength, better water barrier properties, shorter solubilization time and lower elongation at break than those of hydroxypropylmethylcellulose film, respectively. The composite film (Pullulan and hydroxypropylmethylcellulose) with weight ratio (1/2) has higher tensile strength, better water barrier properties, longer solubilization time than those of other ratios. Difference properties of films could be obtained in different weight ratio (Pullulan and hydroxypropylmethylcellulose).


2014 ◽  
Vol 941-944 ◽  
pp. 1133-1140 ◽  
Author(s):  
Shuai Peng ◽  
Li Hong Niu ◽  
Ke Qiang Lai ◽  
Yi Qun Huang

The present study was to investigate the film forming properties of tilapia skin gelatin as affected by the addition of 2%, 5% Arabic gum or pectin (g/g gelatin), as well as 1%, 2% glutaraldehyde (GTA) (g/g gelatin) in an attempt to improve gelatin film properties. Tensile strength (TS) and transparency of gelatin film were improved 36.6% and 30.3% by the addition of Arabic gum, respectively, while the water vapor permeability (WVP) was not affected. The addition of pectin had less effect on the film tensile strength and transparency, but led to 41.7% of increase in WVP. Tensile strength and WVP of gelatin-arabic gum composite film cross-linked with 2% GTA were better than those of 1% GTA cross-linked composite film, though the extensibility and transparency were slightly weak. The FTIR spectra of gelatin films showed that both Arabic gum and pectin formed cross-linkages with gelatin protein molecules, while GTA facilitated the formation of intermolecular bonds, resulting in more stable films.


2021 ◽  
Author(s):  
Ya-Yu Li ◽  
Yan-Ru Bai ◽  
Xin-Qian Zhang ◽  
Xin Liu ◽  
Zhen Dai ◽  
...  

Abstract Three kinds of cellulose nanocrystals (CNCs) were added into waterborne polyurethane (WPU), and nanocomposite films were prepared by solution casting method. The influence of different ionic function groups on microstructure and properties of composite films was investigated, and interaction mechanism between these two components was analyzed. Results show that thermal stability of these composite films are improved by 15℃. Compared with sulfated CNCs (SCNCs) and TEMPO oxidized CNCs (TOCNCs), FE-SEM results prove that cationized CNCs (CaCNCs) have better dispersion in composite films. In addition, fracture surface did not display large cavities, which indicates the interface binding force between WPU and CaCNCs is stronger. The tensile strength and fracture work of CaCNC/WPU composite film increase by 11.9% and by 8.4%, respectively. The oxygen permeability of CaCNC/WPU composite film is the lowest in these composite films, which is 5.00 cm3•cm (cm2•s•Pa)-1. Water vapor permeability of composite films may have a close positive correlation with their hygroscopicity. In all, composite film with CaCNCs has optimal strength, toughness, light transmittance and oxygen barrier properties. There may be opposite ion attraction superimposed hydrogen bond between CaCNCs and WPU in the composite film. The composite films are expected to have applications in food packaging, furniture coatings and biomedical applications.


2013 ◽  
Vol 23 ◽  
pp. 7-15 ◽  
Author(s):  
Yern Chee Ching ◽  
Y. Yahya Rosiyah ◽  
Garlie Li

Polylactides (PLA) based composite films modified with nanoclay content ranges from 0-30 wt% were fabricated using solvent casting method and the mechanical properties, water vapor permeability, oxygen barrier, thermal stability and optical properties were studied. The study showed that the addition of up to 15 wt% of clay has caused a significant improvement of tensile strength of the PLA/nanoclay composite film. However, the further increasing of nanoclay content of >15 wt% of nanoclay has caused a significant reduction in tensile, elongation at break and optical properties of PLA matrix. Both the oxygen and water permeability of the PLA/nanoclay composite film decrease with the increasing of nanoclay contents. Greater water barrier properties would be achieved if the high nanoclay contents of 10-30 wt% were dispersed homogenous within the PLA matrix. The addition of nanoclay greater than 10 wt% affected the appearance of the film (i.e. increasing the haze and ΔE). Thermal analysis result has proved that the melting temperature, crystallization temperature and glass transition temperature of the composite film only slightly affected by the addition of nanoclay due to the immobilization polymer chain in the composite film.


2013 ◽  
Vol 25 ◽  
pp. 128-136 ◽  
Author(s):  
Ching Yern Chee ◽  
Y. Yahya Rosiyah ◽  
Garlie Li

Polylactides (PLA) based composite films modified with nanoclay content ranges from 0-30 wt% were fabricated using solvent casting method and the mechanical properties, water vapor permeability, oxygen barrier, thermal stability and optical properties were studied. The study showed that the addition of up to 15 wt% of clay has caused a significant improvement of tensile strength of the PLA/nanoclay composite film. However, the further increasing of nanoclay content of >15 wt% of nanoclay has caused a significant reduction in tensile, elongation at break and optical properties of PLA matrix. Both the oxygen and water permeability of the PLA/nanoclay composite film decrease with the increasing of nanoclay contents. Greater water barrier properties would be achieved if the high nanoclay contents of 10-30 wt% were dispersed homogenous within the PLA matrix. The addition of nanoclay greater than 10 wt% affected the appearance of the film (i.e. increasing the haze and ΔE). Thermal analysis result has proved that the melting temperature, crystallization temperature and glass transition temperature of the composite film only slightly affected by the addition of nanoclay due to the immobilization polymer chain in the composite film.


Author(s):  
Xinxin Liu ◽  
Xiaofeng Chen ◽  
Junli Ren ◽  
Chunhui Zhang

In order to improve the strength of PVA/xylan composite films and endow them with ultraviolet (UV) shielding ability, TiO2-KH550 nanoparticle was synthesized and added into the PVA/xylan matrix. The TiO2-KH550 nanoparticle dispersed well in the 0.04% sodium hexametaphosphate (SHMP) solution under ultrasonic and stirring treatments. Investigations on the properties of films showed that TiO2-KH550 had the positive impact on improving the strength, moisture and oxygen barrier properties of the composite films. The maximum tensile strength (27.3 MPa), the minimum water vapor permeability (2.75&times;10-11 g&bull;m-1&bull;s-1&bull;Pa-1) and oxygen permeability (4.013 cm3&bull;m-2&bull;24h-1&bull;0.1MPa-1) were obtained under the addition of 1.5% TiO2-KH550. The tensile strength of TiO2-KH550 reinforced composite film was increased by 70% than that of the pure PVA/xylan composite film, and the water vapor and oxygen permeability were decreased by 31% and 41%, respectively. Moreover, the UV transmittance of film at the wavelength of 400 nm was almost zero when adding 1.5~2.5% of TiO2-KH550, which indicated the PVA/xylan composite films were endowed with excellent UV light shielding ability.


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. 


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 469 ◽  
pp. 156-161 ◽  
Author(s):  
Hong Pan ◽  
Dan Xu ◽  
Qin Liu ◽  
Hui Qing Ren ◽  
Min Zhou

Starch-based nanocomposite films were fabricated by the incorporation of different amounts of nanodiamond (ND) particles. These films were characterized by SEM, FT-IR, TGA, tensile testing and water vapor permeability measurement. It was observed that at low loadings, ND dispersed well in starch matrix. However, as the loading amount increased, aggregates as large as several micrometers appeared. The physical blending of ND with starch didnt change the thermal degradation mechanisms of starch films, only increased the char residues. As the ND loading increased, the tensile strength of composite films increased but the elongation at break decreased. However, the water vapor permeability increased as the loading of ND increased due to the increased microspores in films. With further modifications, ND may be considered as a novel of biocompatible nanofillers for reinforcement of biopolymers for food packaging applications.


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