The Structure and Properties Research on Poly(Lactide-Co-Trimethylene Carbonate) Film Prepared by Blow Molding

2013 ◽  
Vol 750-752 ◽  
pp. 1930-1933
Author(s):  
Jiang Ping Chang ◽  
Hong Li Li ◽  
Ying Jie Zhang ◽  
Guo Xian Zhou ◽  
Ming Long Yuan

The poly (lactide-co-trimethylene carbonate) copolymers are prepared by ring opening polymerization and catalyzed by SnOct and their films are prepared by blow molding. The 1HNMR study demonstrates that PLA-PTMC copolymers were successfully obtained and the graft way is A-B model. The water vapor permeability (WVP) of the films decreases with the increasing TMC content due to the formation of denser structure. The mechanical measurement reveals that the tensile strength of blown films has been declined with the increasing TMC content, but the elongation at break is improved and the tensile strength can be satisfied for the requirement of film product. Therefore, the copolymer film will be great prospect in the application of food and beverage packing.

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.;


2011 ◽  
Vol 233-235 ◽  
pp. 1162-1166 ◽  
Author(s):  
Feng Jun Wang ◽  
Jian Qing Wang ◽  
Mei Xu

Cellulose-based composites packaging films containing various amounts of modified nano-SiO2 were prepared by utilizing hardwood pulps as natural cellulose resource through NMMO-technology to improve the mechanical properties, permeability for oxygen and water vapor etc. The tensile strength, elongation at break, thermal stability and permeability of the cellulose composites films as a function of the content of modified nano-SiO2 were studied. The investigation suggested that the capabilities of composites films with 2 wt.% modified nano-SiO2 added were improved largely, compared to pure cellulose films, when the diameter of particles is 30nm. The tensile strength was increased from 8.95 to 17.37 MPa and the elongation at break of the cellulose composites films was improved from 41.11% to 58.34%. The composites films with rational mechanical properties have adjustable oxygen permeability (7.90×10-15-72.18×10-15 cm3·cm/cm2·s·Pa) and water vapor permeability (7.12×10-13-5.32×10-13g·cm/cm2·s·Pa). And thermal stability of the composites films was advanced through adding modified nano-SiO2.


2021 ◽  
Vol 55 (7-8) ◽  
pp. 849-865
Author(s):  
PARTHIBAN FATHIRAJA ◽  
SUGUMAR GOPALRAJAN ◽  
MASILAN KARUNANITHI ◽  
MURALIDHARAN NAGARAJAN ◽  
MOHAN CHITRADURGA OBAIAH ◽  
...  

The aim of the study has been to develop a biodegradable film from marine polysaccharides. The optimization of polysaccharides quantity for the composite film was sought by empirical response surface methodology. The Box–Behnken Model Design was applied to optimize the concentration of chitosan (1.0-2.0% (w/v), agar (1.0-2.0% (w/v) and glycerol (0.1-0.5% (w/v) as independent variables to achieve the goal. The overall desirability function fits with the quadratic model (0.862043) at a significant level (p < 0.05) for the optimum concentration of chitosan (1.5% (w/v), agar (2.0% (w/v) and glycerol (0.41% (w/v) to obtain the minimum water vapor permeability (7.25 10-10g m m-2 Pa-1 s-1) and maximum tensile strength (12.21 Ma P), elongation at break (7.32%) and puncture resistance (16.18 N) in the optimized composite film. The absolute residual errors of experimental and predicted responses were between 1.24 and 3.56% acceptable levels. Attenuated total reflection–Fourier transform infrared spectroscopy confirmed the intermolecular non-covalent hydrogen bond between the hydroxyl groups of agar and glycerol with the amino group of chitosan. 3D atomic force microscopy images revealed that the chitosan, agar and glycerol film has layer-by-layer smooth surface properties due to homogenous interaction among the polysaccharides; this provides the film with good mechanical properties and with functional application. Chitosan was found to be responsible for the lower level of water vapor permeability and higher puncture resistance of the film. Tensile strength and elongation at break were influenced by agar and glycerol. The whiteness of the film was negatively affected with the concentration of chitosan.


Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 348
Author(s):  
Pornchai Rachtanapun ◽  
Pensak Jantrawut ◽  
Warinporn Klunklin ◽  
Kittisak Jantanasakulwong ◽  
Yuthana Phimolsiripol ◽  
...  

Bacterial cellulose from nata de coco was prepared from the fermentation of coconut juice with Acetobacter xylinum for 10 days at room temperature under sterile conditions. Carboxymethyl cellulose (CMC) was transformed from the bacterial cellulose from the nata de coco by carboxymethylation using different concentrations of sodium hydroxide (NaOH) and monochloroacetic acid (MCA) in an isopropyl (IPA) medium. The effects of various NaOH concentrations on the degree of substitution (DS), chemical structure, viscosity, color, crystallinity, morphology and the thermal properties of carboxymethyl bacterial cellulose powder from nata de coco (CMCn) were evaluated. In the carboxymethylation process, the optimal condition resulted from NaOH amount of 30 g/100 mL, as this provided the highest DS value (0.92). The crystallinity of CMCn declined after synthesis but seemed to be the same in each condition. The mechanical properties (tensile strength and percentage of elongation at break), water vapor permeability (WVP) and morphology of CMCn films obtained from CMCn synthesis using different NaOH concentrations were investigated. The tensile strength of CMCn film synthesized with a NaOH concentration of 30 g/100 mL increased, however it declined when the amount of NaOH concentration was too high. This result correlated with the DS value. The highest percent elongation at break was obtained from CMCn films synthesized with 50 g/100 mL NaOH, whereas the elongation at break decreased when NaOH concentration increased to 60 g/100 mL.


2020 ◽  
Vol 987 ◽  
pp. 112-117
Author(s):  
Wancheng Sittikijyothin ◽  
Khanaphit Khumduang ◽  
Chularat Hongvaleerat ◽  
Rattanaphol Mongkholrattanasit

The gum edible films were prepared from Caesalpinia pulcherrima seeds. The effects of plasticizer types and contents on physical and mechanical properties of gum edible film were investigated. Three plasticizers as glycerol and sorbitol and propylene glycol at different adding concentrations (0.5%, 1.0%, and 1.5%) were used. Glycerol provided flexible and sticky films with the highest water vapour permeability and elongation at break but the lowest tensile strength. In contrast, propylene glycol provided brittle films with the highest tensile strength but the lowest elongation at break and water vapour permeability. In addition, increasing in plasticizer content resulted in decreased tensile strength concomitant with an increased in elongation at break and water vapor permeability.


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.


2021 ◽  
Vol 60 (1) ◽  
Author(s):  
Gema Morales-Olán ◽  
María Antonieta Ríos-Corripio ◽  
Aleida Selene Hernández-Cázares ◽  
Placido Zaca-Morán ◽  
Silvia Luna-Suárez ◽  
...  

Research background. Amaranth flour (Amaranthus hypochondriacus) produces films with excellent barrier properties against water vapor, allowing food preservation, but the mechanical properties are poor versus to synthetic films. One strategy to improve these properties is the incorporation of nanoparticles. The particles can also serve as a vehicle for the addition of antioxidants agents into the films. The objective of this work was to optimize the formulation for preparation of amaranth flour films treated with antioxidant chia (Salvia hispanica L.) extract-loaded chitosan particles using RSM. Experimental approach. Chitosan nanoparticles with the extract were synthesized by ionic gelation, and the films were made by the casting method. Three independent variables were assigned: amaranth flour (4-6 %), glycerol (25-35 %), and chitosan nanoparticles loaded with the chia extract (0-0.75 %). We then evaluated the physical (thickness), mechanical (tensile strength, Young´s modulus, and elongation), barrier (water vapor permeability, moisture, and water solubility), and antioxidant properties of the films. The experimental results of the properties were analyzed using a Box-Behnken experimental design generating 15 runs with three replicates at the central point. Results and conclusions. Second and third order polynomial models were obtained from the ANOVA analysis of the evaluated responses, and high coefficients of determination were found (0.91-1.0). The films presented a water vapor permeability of 0.82-2.39·10-7 (g·mm)/(Pa·s·m2), a tensile strength of 0.33-1.63 MPa, and antioxidant activity of 2.24-5.65 %. The variables had different effects on the films: The glycerol negatively affected their properties, and the permeability values increased with amaranth flour concentration. The nanoparticles improved the mechanical, barrier, and antioxidant properties of the films versus films without nanosystems. The optimal formulation was 4 % amaranth flour, 25 % of glycerol, and 0.36 % of chitosan nanoparticles. The optimized films had better mechanical (1.62 MPa) properties, a low water vapor permeability value (0.91·10-7 (g·mm)/(Pa·s·m2)), and moderate antioxidant activity (6.43 %). Novelty and scientific contribution. The results show the effect of chitosan nanoparticles on the properties of amaranth flour films for the first time. The resulting equations are useful in the design of food packaging.


Coatings ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 384
Author(s):  
Juan Tirado-Gallegos ◽  
Paul Zamudio-Flores ◽  
José Ornelas-Paz ◽  
Claudio Rios-Velasco ◽  
Guadalupe Olivas Orozco ◽  
...  

Apple starch films were obtained from apples harvested at 60, 70, 80 and 90 days after full bloom (DAFB). Mechanical properties and water vapor permeability (WVP) were evaluated. The apple starch films at 70 DAFB presented higher values in the variables of tensile strength (8.12 MPa), elastic modulus (3.10 MPa) and lower values of water vapor permeability (6.77 × 10−11 g m−1 s−1 Pa−1) than apple starch films from apples harvested at 60, 80 and 90 DAFB. Therefore, these films were chosen to continue the study incorporating ellagic acid (EA). The EA was added at three concentrations [0.02% (FILM-EA0.02%), 0.05% (FILM-EA0.05%) and 0.1% (FILM-EA0.1%) w/w] and compared with the apple starch films without EA (FILM-Control). The films were characterized by their physicochemical, optical, morphological and mechanical properties. Their thermal stability and antioxidant capacity were also evaluated. The FILM-Control and FILM-EA0.02% showed a uniform surface, while FILM-EA0.05% and FILM-EA0.1% showed a rough surface and insoluble EA particles. Compared to FILM-Control, EA modified the values of tensile strength, elasticity modulus and elongation at break. The antioxidant capacity increased as EA concentration did. EA incorporation allowed obtaining films with higher antioxidant capacity, capable of blocking UV light with better mechanical properties than film without EA.


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.


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