scholarly journals Electrospun Poly(ethylene-co-vinyl alcohol)/Graphene Nanoplatelets Composites of Interest in Intelligent Food Packaging Applications

Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 745 ◽  
Author(s):  
Sergio Torres-Giner ◽  
Yolanda Echegoyen ◽  
Roberto Teruel-Juanes ◽  
Jose Badia ◽  
Amparo Ribes-Greus ◽  
...  
Keyword(s):  
Vinyl Alcohol ◽  
Food Packaging ◽  
Thermal Characterization ◽  
Graphite Powder ◽  
Dielectric Behavior ◽  
Graphene Nanoplatelets ◽  
Nanocomposite Fiber ◽  
Nanocomposite Fibers ◽  
Contact Transparency ◽  
Poly Ethylene

Graphene nanoplatelets (GNPs) were synthetized from graphite powder and, thereafter, embedded in poly(ethylene-co-vinyl alcohol) (EVOH) fibers by electrospinning in the 0.1–2 wt.-% range. The morphological, chemical, and thermal characterization performed on the electrospun nanocomposite fibers mats revealed that the GNPs were efficiently dispersed and rolled along the EVOH fibrilar matrix up to contents of 0.5 wt.-%. Additionally, the dielectric behavior of the nanocomposite fibers was evaluated as a function of the frequency range and GNPs content. The obtained results indicated that their dielectric constant rapidly decreased with the frequency increase and only increased at low GNPs loadings while the nanocomposite fiber mats became electrically conductive, with the maximum at 0.5 wt.-% GNPs content. Finally, the electrospun mats were subjected to a thermal post-treatment and dark films with a high contact transparency were obtained, suggesting that the nanocomposites can be used either in a nonwoven fibers form or in a continuous film form. This study demonstrates the potential of electrospinning as a promising technology to produce GNPs-containing materials with high electrical conductivity that can be of potential interest in intelligent packaging applications as “smart” labels or tags.

scholarly journals Development and Characterization of Electrospun Fiber-Based Poly(ethylene-co-vinyl Alcohol) Films of Application Interest as High-Gas-Barrier Interlayers in Food Packaging

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2061
Author(s):  
Beatriz Melendez-Rodriguez ◽  
Sergio Torres-Giner ◽  
Lorenzo Zavagna ◽  
Chris Sammon ◽  
Luis Cabedo ◽  
...  
Keyword(s):  
Vinyl Alcohol ◽  
Food Packaging ◽  
Electrospun Fiber ◽  
Tensile Modulus ◽  
Ethylene Vinyl Alcohol ◽  
Nanocomposite Fiber ◽  
General Terms ◽  
Hybrid Copolymer ◽  
Poly Ethylene ◽  
Barrier Polymers

In the present study, poly(ethylene-co-vinyl alcohol) with 44 mol % ethylene content (EVOH44) was managed to be processed, for the first time, by electrospinning assisted by the coaxial technology of solvent jacket. In addition to this, different suspensions of cellulose nanocrystals (CNCs), with contents ranging from 0.1 to 1.0 wt %, were also electrospun to obtain hybrid bio-/non-bio nanocomposites. The resultant fiber mats were thereafter optimally annealed to promote interfiber coalescence at 145 °C, below the EVOH44 melting point, leading to continuous transparent fiber-based films. The morphological analysis revealed the successful distribution of CNCs into EVOH44 up to contents of 0.5 wt %. The incorporation of CNCs into the ethylene-vinyl alcohol copolymer caused a decrease in the crystallization and melting temperatures (TC and Tm) of about 12 and 7 °C, respectively, and also crystallinity. However, the incorporation of CNCs led to enhanced thermal stability of the copolymer matrix for a nanofiller content of 1.0 wt %. Furthermore, the incorporation of 0.1 and 0.5 wt % CNCs produced increases in the tensile modulus (E) of ca. 38% and 28%, respectively, but also yielded a reduction in the elongation at break and toughness. The oxygen barrier of the hybrid nanocomposite fiber-based films decreased with increasing the CNCs content, but they were seen to remain high barrier, especially in the low relative humidity (RH) regime, i.e., at 20% RH, showing permeability values lower than 0.6 × 10−20 m3·m·m−2·Pa−1·s−1. In general terms, an optimal balance in physical properties was found for the hybrid copolymer composite with a CNC loading of 0.1 wt %. On the overall, the present study demonstrates the potential of annealed electrospun fiber-based high-barrier polymers, with or without CNCs, to develop novel barrier interlayers to be used as food packaging constituents.

scholarly journals In situ alignment of graphene nanoplatelets in poly(vinyl alcohol) nanocomposite fibers with controlled stepwise interfacial exfoliation

2019 ◽  
Vol 1 (7) ◽  
pp. 2510-2517 ◽  
Author(s):  
Weiheng Xu ◽  
Sayli Jambhulkar ◽  
Rahul Verma ◽  
Rahul Franklin ◽  
Dharneedar Ravichandran ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Vinyl Alcohol ◽  
Graphene Nanoplatelets ◽  
Poly Vinyl Alcohol ◽  
Graphene Nanoplatelet ◽  
Nanocomposite Fibers

Exfoliated and aligned continuous graphene nanoplatelet channels with enhanced mechanical properties and superior electrical conductivity.

scholarly journals Crosslinking of lignin/poly(vinyl alcohol) nanocomposite fiber webs and their antimicrobial and ultraviolet-protective properties

2017 ◽  
Vol 89 (1) ◽  
pp. 3-12 ◽  
Author(s):  
Eunsil Lee ◽  
Youjung Song ◽  
Seungsin Lee
Keyword(s):  
Vinyl Alcohol ◽  
Aqueous Media ◽  
Reduction Rate ◽  
Environmentally Benign ◽  
Poly Vinyl Alcohol ◽  
Protective Properties ◽  
Renewable Biomass ◽  
Nanocomposite Fiber ◽  
Nanocomposite Fibers ◽  
The Stability

Lignin/poly(vinyl alcohol) (PVA) nanocomposite fibers with different lignin concentrations were developed via electrospinning to investigate further possible applications of lignin, an under-utilized renewable biomass material. The antimicrobial and ultraviolet (UV) absorption properties of lignin/PVA nanocomposite fibers were evaluated to determine whether the inherent functionalities of lignin remain in the final material. An environmentally benign crosslinking method was sought to increase the stability of lignin/PVA nanocomposite fibers in aqueous media. The crosslinking and insolubilization of the lignin/PVA nanocomposite fibers was achieved by combining several crosslinking techniques: water vapor treatment at 80℃ for 180 min, photo-irradiation for 30 min under visible light at a distance of 17 cm, and heat treatment at 200℃ for 60 min. Both lignin/PVA nanocomposite fiber webs—containing 50 and 85 wt% of lignin at a 3.0 g/m2 web area density, respectively—showed a 99.9% reduction rate against Staphylococcus aureus, but no reduction against Escherichia coli. The same systems exhibited ultraviolet protection factors (UPF) of >50, indicating excellent UV protection. These findings demonstrate the potential of lignin-based composite fibers, and may widen the range of applications for this biomass material.

scholarly journals Thermal Properties, Isothermal Decomposition by Direct Analysis in Real-Time-Of-Flight Mass Spectrometry and Non Isothermal Crystallization Kinetics of Poly(Ethylene-Co-Vinyl Alcohol)/Poly(ε-Caprolactone) Blend

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 292
Author(s):  
Abdulaziz Ali Alghamdi ◽  
Hussain Alattas ◽  
Waseem Sharaf Saeed ◽  
Abdel-Basit Al-Odayni ◽  
Ahmed Yacine Badjah Hadj Ahmed ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Real Time ◽  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Vinyl Alcohol ◽  
Time Of Flight ◽  
Direct Analysis ◽  
Isothermal Crystallization Kinetics ◽  
Flight Mass Spectrometry ◽  
Poly Ethylene

A series of poly(ethylene-co-vinyl alcohol)/poly(ε-caprolactone) blends with different compositions were prepared using solvent casting. The miscibility of this pair of polymers was investigated using differential scanning calorimetry (DSC), and proved by a negative Flory interaction parameter value calculated from the Nishi–Wang equation. The miscibility of this blend was also confirmed by scanning electronic microscopy (SEM). The thermal behaviors of the obtained materials were investigated by DSC, thermogravimetric analysis, and direct analysis in real-time–time-of-flight mass spectrometry and the results obtained were very relevant. Furthermore, the crystalline properties of the obtained materials were studied by DSC and X-ray diffraction where the Ozawa approach was adopted to investigate the non-isothermal crystallization kinetics. The results obtained revealed that this approach described the crystallization process well.

Effect of Cobalt Stearate and Vegetable Oil on Uv and Biodegradation of Linear Low-Density Poly(Ethylene)-Poly(Vinyl Alcohol) Blends

2011 ◽  
Vol 2 (4) ◽  
pp. 131-148 ◽  
Author(s):  
Francis Vidya ◽  
Subin S. Raghul ◽  
Sarita G Bhat ◽  
Eby Thomas Thachil
Keyword(s):  
Vegetable Oil ◽  
Vinyl Alcohol ◽  
Water Soluble ◽  
Poly Vinyl Alcohol ◽  
Low Density ◽  
Compression Moulding ◽  
Melt Mixing ◽  
Degradation Behaviour ◽  
Moulding Process ◽  
Poly Ethylene

The main objective of this study was to enhance the rate of UV and biodegradation of polyethylene by incorporating biodegradable materials and prooxidants. Prooxidants such as transition metal complexes are capable of initiating photooxidation and polymer chain cleavage, rendering the product more susceptible to biodegradation. In this work, the effect of (1) a metallic photoinitiator, cobalt stearate, and (2) different combinations of cobalt stearate and vegetable oil on the photooxidative degradation of linear low-density poly(ethylene)-poly(vinyl alcohol) (LLDPE/PVA) blend films has been investigated. For this, film-grade LLDPE was blended with different proportions of PVA. PVA is widely used in the industrial field, and recently it has attracted increasing attention as a water-soluble biodegradable polymer. Cobalt stearate and vegetable oil were added to the blends as prooxidants. The blends were prepared by melt mixing in a Thermo HAAKE Polylab system. Thin films containing these additives were prepared by a subsequent compression moulding process. The effect of UV exposure on LLDPE/PVA films in the presence as well as absence of these additives was investigated. Tensile properties, FTIR spectra, and scanning electron microscopy (SEM) were employed to investigate the degradation behaviour. It was found

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