scholarly journals The Role of Structure and Interactions in Thermoplastic Starch–Nanocellulose Composites

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3186
Author(s):  
Emília Csiszár ◽  
Dávid Kun ◽  
Erika Fekete
Keyword(s):  
Composite Films ◽  
Water Vapor Permeability ◽  
High Water ◽  
Thermoplastic Starch ◽  
Vapor Permeability ◽  
Visible Spectroscopy ◽  
Different Types ◽  
Additional Water ◽  
Human Eyes

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.

scholarly journals Improved Process to Obtain Nanofibrillated Cellulose (CNF) Reinforced Starch Films with Upgraded Mechanical Properties and Barrier Character

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1071 ◽  
Author(s):  
Luis Angel Granda ◽  
Helena Oliver-Ortega ◽  
Maria José Fabra ◽  
Quim Tarrés ◽  
Maria Àngels Pèlach ◽  
...  
Keyword(s):  
Composite Films ◽  
High Capacity ◽  
Water Vapor Permeability ◽  
Barrier Properties ◽  
Thermoplastic Starch ◽  
Nanofibrillated Cellulose ◽  
Vapor Permeability ◽  
The Matrix ◽  
Starch Films ◽  
The One

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.

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 ◽  
...  
Keyword(s):  
Composite Films ◽  
Water Vapor Permeability ◽  
Thermoplastic Starch ◽  
Mechanical Tests ◽  
Vapor Permeability ◽  
Relative Crystallinity ◽  
Elongation At Break ◽  
Low Concentrations ◽  
Starch Nanoparticles ◽  
Amorphous Character

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.

scholarly journals Few-layer graphene aqueous suspensions for polyurethane composite coatings

MRS Advances ◽  
2016 ◽  
Vol 2 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Eunice Cunha ◽  
Fernando Duarte ◽  
M. Fernanda Proença ◽  
M. Conceição Paiva
Keyword(s):  
Mechanical Properties ◽  
Tensile Testing ◽  
Composite Coatings ◽  
Composite Films ◽  
Water Vapor Permeability ◽  
Waterborne Polyurethane ◽  
Vapor Permeability ◽  
Layer Graphene ◽  
Polyurethane Composite ◽  
Few Layer Graphene

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.

Fabrication of Composite Films Based on Chitosan and Vegetable-Tanned Collagen Fibers Crosslinked with Genipin

2021 ◽  
Vol 116 (10) ◽  
Author(s):  
Jie Liu ◽  
Yanchun Liu ◽  
Eleanor M. Brown ◽  
Zhengxin Ma ◽  
Cheng-Kung Liu
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Water Vapor ◽  
Composite Film ◽  
Composite Films ◽  
Value Added ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
Leather Industry ◽  
Compact Structure

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. 

scholarly journals Preparation and Properties of Corn Starch/Chitin Composite Films Cross-Linked by Maleic Anhydride

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1606
Author(s):  
Peng Yin ◽  
Jinglong Liu ◽  
Wen Zhou ◽  
Panxin Li
Keyword(s):  
Maleic Anhydride ◽  
Corn Starch ◽  
Composite Films ◽  
Water Vapor Permeability ◽  
Contact Angles ◽  
Vapor Permeability ◽  
Water Contact ◽  
Elongation At Break ◽  
Shrimp Shell ◽  
Starch Films

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.

scholarly journals Morphology, order, light transmittance, and water vapor permeability of aluminum-coated polypropylene zeolite composite films

2010 ◽  
Vol 120 (3) ◽  
pp. 1671-1678 ◽  
Author(s):  
Devrim Balköse ◽  
Kaan Oguz ◽  
Lutfi Ozyuzer ◽  
Suleyman Tari ◽  
Esen Arkis ◽  
...  
Keyword(s):  
Water Vapor ◽  
Composite Films ◽  
Water Vapor Permeability ◽  
Light Transmittance ◽  
Vapor Permeability ◽  
Zeolite Composite

THE USE OF FLY ASH ALUMINOSILICATE MICROSPHERES IN THE LIME DRY MIXES FOR FINISHING AERATED CONCRETE

2017 ◽  
Vol 2 (3) ◽  
pp. 6-8 ◽  
Author(s):  
Логанина ◽  
Valentina Loganina ◽  
Фролов ◽  
Mikhail Frolov
Keyword(s):  
Thermal Conductivity ◽  
Water Vapor ◽  
Fly Ash ◽  
Water Vapor Permeability ◽  
High Water ◽  
Vapor Permeability ◽  
Low Thermal Conductivity ◽  
Aerated Concrete ◽  
Sufficient Strength

The application of ash microspheres in lime dry construction mixtures, designed for finishing aerated. It is shown that on the basis of dry ash mixtures with microspheres characterized by coating a sufficient strength, low thermal conductivity, high water vapor permeability, resistance to the action of the slanting rain.

Preparation and Characterization of Corn Starch-Nanodiamond Composite Films

2013 ◽  
Vol 469 ◽  
pp. 156-161 ◽  
Author(s):  
Hong Pan ◽  
Dan Xu ◽  
Qin Liu ◽  
Hui Qing Ren ◽  
Min Zhou
Keyword(s):  
Water Vapor ◽  
Food Packaging ◽  
Corn Starch ◽  
Composite Films ◽  
Water Vapor Permeability ◽  
Nanocomposite Films ◽  
Vapor Permeability ◽  
Ft Ir ◽  
Loading Amount ◽  
Physical Blending

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.

Effects of Zein on Film-Forming Ability and Properties of Wheat Gluten Films

2013 ◽  
Vol 750-752 ◽  
pp. 1582-1585
Author(s):  
Chun Hong Zhang ◽  
Nan Chang ◽  
Chen Li ◽  
Xin Hua Li
Keyword(s):  
Water Retention ◽  
Wheat Gluten ◽  
Composite Films ◽  
Antibacterial Properties ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
Hydrogen Bond Interaction ◽  
Elongation At Break ◽  
Film Forming ◽  
And Staphylococcus Aureus

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.

scholarly journals Packaging Composite Films Fabricated from Cellulose Pulp with Polyurethane and Curcumin by Using NMMO ionic Liquid Solvent

2021 ◽  
Author(s):  
Chaehyun Jo ◽  
Sam Soo Kim ◽  
Srinivasan Ramalingam ◽  
Prabakaran D. S ◽  
Balasubramanian Rukmanikrishnan ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Composite Films ◽  
Water Vapor Permeability ◽  
Cost Effective ◽  
Barrier Properties ◽  
Vapor Permeability ◽  
Visual Appearance ◽  
Cellulose Pulp ◽  
Cost Effective Method ◽  
Uv Transmittance

Abstract Cellulose pulp (CP), polyurethane (PU), and curcumin-based biocompatible composite films were prepared using a simple cost-effective method. These materials dissolved well in the ionic liquid solvent N-methylmorpholine N-oxide. Significant structural and microstructural changes were observed in CP upon the addition of PU. These changes were studied using Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The 5% and 10% gravimetric losses of the CP/PU/curcumin composite were found to be in the range 87.2–182.3 ºC and 166.7–249.8 ºC, respectively. The addition of PU significantly improved the thermal stability and water barrier properties of the composites. All the composites exhibited single Tg values in the range 147.4–154.2 ºC. The tensile strength of CP was measured to be 93.2 MPa, which dropped to 14.1 MPa for the 1:0.5 CP/PU composite and then steadily increased to 30.5 MPa with further addition of PU. The elongation at break of the composites decreased from 8.1 to 3.7% with the addition of PU. The addition of PU also improved the water vapor permeability (3.96 ×10–9 to 1.75 ×10–9 g m–1 s–1 Pa–1) and swelling ratio (285 to 202%) of the CP composite films. The CP/PU/curcumin composite exhibited good antioxidant activity and no cytotoxicity when tested on the HaCat cell line. The visual appearance and UV transmittance (86.2–32.9% at 600 nm) of the CP composite films were significantly altered by the incorporation of PU and curcumin. This study demonstrates that CP/PU/curcumin composites can be used for various packaging and biomedical applications.

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