scholarly journals Lactide-Valerolactone Copolymers for Packaging Applications

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 52
Author(s):  
Ainara Sangroniz ◽  
Leire Sangroniz ◽  
Shaghayegh Hamzehlou ◽  
Nora Aranburu ◽  
Haritz Sardon ◽  
...  
Keyword(s):  
Potential Application ◽  
Oxygen Permeability ◽  
Barrier Properties ◽  
Intermediate Water ◽  
Kinetics Of ◽  
Composition Drift

Lactide-valerolactone copolymers have potential application in the packaging sector. Different copolymers were synthesized, and the kinetics of the copolymerization reactions and the microstructure of the copolymers were analysed. Lactide showed higher reactivity than valerolactone which leads to composition drift through the reaction. Thermal, mechanical and barrier properties of the selected copolymers were studied. Overall, the incorporation of valerolactone results in copolymers with higher ductility than poly(lactide) with intermediate water and oxygen permeability which makes these materials appropriate candidates for use in the packaging sector.

scholarly journals Fabrication and characterization of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) modified with nano-montmorillonite biocomposite

e-Polymers ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 038-046
Author(s):  
Xu Yan ◽  
Wanru Zhou ◽  
Xiaojun Ma ◽  
Binqing Sun
Keyword(s):  
Thermal Stability ◽  
Oxygen Permeability ◽  
Water Vapor Permeability ◽  
Barrier Properties ◽  
Nucleating Agent ◽  
Vapor Permeability ◽  
Casting Method ◽  
Increasing Trend ◽  
Solution Casting Method

Abstract In this study, a poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) modified with nano-montmorillonite biocomposite (MMT/PHBH) was fabricated by solution-casting method. The results showed that the addition of MMT increased the crystallinity and the number of spherulites, which indicated that MMT was an effective nucleating agent for PHBH. The maximum decomposition peak of the biocomposites moved to a high temperature and residue presented an increasing trend. The biocomposites showed the best thermal stability at 1 wt% MMT. Compared with PHBH, 182.5% and 111.2% improvement in elastic modulus and tensile strength were obtained, respectively. Moreover, the oxygen permeability coefficient and the water vapor permeability of MMT/PHBH biocomposites decreased by 43.9% and 6.9%, respectively. It was also found that the simultaneous enhancements on the crystallizing, thermal stability, mechanical, and barrier properties of biocomposites were mainly caused by the formation of intercalated structure between PHBH and MMT.

scholarly journals Gelatin Beads/Hemp Hurd as pH Sensitive Devices for Delivery of Eugenol as Green Pesticide

2021 ◽  
Author(s):  
Gianluca Viscusi ◽  
Giuliana Gorrasi
Keyword(s):  
Release Kinetics ◽  
Barrier Properties ◽  
Ph Sensitive ◽  
Release Behavior ◽  
Sorption Coefficient ◽  
Highly Sensitive ◽  
Mean Diameter ◽  
Ph Conditions ◽  
Kinetics Of ◽  
Hemp Hurd

AbstractIn this paper gelatin beads reinforced with natural hemp hurd have been produced as pH sensitive devices for the release of eugenol, as green pesticide. The composites beads, with a mean diameter of about 1 mm, were obtained by polymer droplet gelation in sunflower oil. Thermal properties were evaluated showing no noticeable difference after the introduction of hemp hurd. Barrier properties demonstrated an improvement of hydrophobization. The introduction of 5% w/w of hemp hurd led to a reduction of sorption coefficient of about 85% compared to unloaded gelatin beads. Besides, the diffusion coefficient decreased, introducing 5% w/w of hemp hurd, from 8.91 × 10−7 to 0.77 × 10−7 cm2/s. Swelling and dissolution phenomena of gelatin beads were studied as function of pH. The swelling of gelatin beads raised as pH increased up to 2.3 g/g, 9.1 g/g and 27.33 g/g at pH 3, 7 and 12, respectively. The dissolution rate changed from 0.034 at pH 3 to 0.077 h−1 at pH 12. Release kinetics of eugenol at different pH conditions were studied. The released eugenol after 24 h is 98%, 91%, 81 and 63% w/w (pH 3), 87%, 62%, 37 and 32 wt% (pH 7) and 81%, 68%, 60 and 52 wt% (pH 12) for unloaded gelatin beads and gelatin beads with 1%, 3 and 5% of hemp hurd, respectively. The eugenol release behavior was demonstrated to be highly sensitive to the pH release medium, which allows to tune such devices as green pesticide release systems in soils with different level of acidity/basicity.

An Investigation of the Barrier Properties and of the Residual Acetaldehyde in Polyethylene Terephthalate Composites

2017 ◽  
Vol 44 (12) ◽  
pp. 19-22
Author(s):  
A.S. Shabaev ◽  
S.Yu. Khashirova ◽  
A.K. Mikitaev ◽  
I.V. Musov ◽  
A.L. Slonov
Keyword(s):  
Carbon Dioxide ◽  
Polymer Composites ◽  
Polyethylene Terephthalate ◽  
Oxygen Permeability ◽  
Gas Permeability ◽  
Polymeric Materials ◽  
Barrier Properties ◽  
Diffusion Cell ◽  
Polybutylene Terephthalate

The diffusion cell to a Tsvet-800 chromatograph for determining the gas permeability of polymeric materials has been optimised. The oxygen permeability and the carbon dioxide permeability of polymer composites based on polyethylene terephthalate and polybutylene terephthalate have been studied. The optimum compositions, combining high barrier properties and a low acetaldehyde content, have been found.

scholarly journals Development of Biodegradable Whey-Based Laminate Functionalised by Chitosan–Natural Extract Formulations

2020 ◽  
Vol 21 (10) ◽  
pp. 3668
Author(s):  
Sanja Potrč ◽  
Lidija Fras Zemljič ◽  
Meta Sterniša ◽  
Sonja Smole Možina ◽  
Olivija Plohl
Keyword(s):  
Antimicrobial Activity ◽  
Oxygen Permeability ◽  
Surface Composition ◽  
Antioxidant Properties ◽  
Chitosan Nanoparticles ◽  
Barrier Properties ◽  
Penicillium Verrucosum ◽  
Natural Extracts ◽  
Positive Effect ◽  
Macromolecular Solution

In this research, antimicrobial polysaccharide chitosan and natural extracts were used as surface coating of a plastic laminate with an integrated whey layer on the inside. The aim was to establish the biodegradable and active concept of packaging laminates. For this purpose, chitosan nanoparticles (CSNPs) with embedded rosemary or cinnamon extracts were synthesised and characterised. Additionally, a whey-based laminate was functionalised: i) chitosan macromolecular solution was applied as first layer and ii) cinnamon or rosemary extracts encapsulated in CSNPs were applied as upper layer (layer wise deposition). Such functionalised whey-based laminate was physicochemically characterized in terms of elemental surface composition, wettability, morphology and oxygen permeability. The antimicrobial activity was tested against Staphylococcus aureus, Escherichia coli, Aspergillus flavus and Penicillium verrucosum. The antioxidant properties were determined using the ABTS assay. It could be shown that after functionalization of the films with the above-mentioned strategy, the wettability was improved. Furthermore, such whey-based laminates still show excellent barrier properties, good antimicrobial activity and a remarkable antioxidative activity. In addition to the improved biodegradability, this type of lamination could also have a positive effect on the shelf-life of products packaged in such structured films.

Effects of Phase Change and Oxygen Permeability in Oxide Scales on Oxidation Kinetics of ZrB2and HfB2

2009 ◽  
Vol 92 (5) ◽  
pp. 1079-1086 ◽  
Author(s):  
Triplicane A. Parthasarathy ◽  
Robert A. Rapp ◽  
Mark Opeka ◽  
Ronald J. Kerans
Keyword(s):  
Phase Change ◽  
Oxidation Kinetics ◽  
Oxygen Permeability ◽  
Oxide Scales ◽  
Kinetics Of

The kinetics of the loss of all-trans retinol at low and intermediate water activity in air in the dark

1995 ◽  
Vol 52 (3) ◽  
pp. 267-273 ◽  
Author(s):  
F. Manan ◽  
A. Baines ◽  
Joan Stone ◽  
Janice Ryley
Keyword(s):  
Water Activity ◽  
Intermediate Water ◽  
Kinetics Of

scholarly journals EDIBLE WHEAT GLUTEN FILMS: DEVELOPMENT, MECHANICAL AND BARRIER PROPERTIES AND APPLICATION TO STRAWBERRIES ( Fragaria Ananassa)

2002 ◽  
Vol 20 (2) ◽  
Author(s):  
PATRICIA S. TANADA-PALMU ◽  
CARLOS GROSSO
Keyword(s):  
Mechanical Properties ◽  
Water Solubility ◽  
Oxygen Permeability ◽  
Wheat Gluten ◽  
Barrier Properties ◽  
Fragaria Ananassa ◽  
Percent Elongation ◽  
Elongation At Break ◽  
Ph Values ◽  
Low Concentrations

Filmes de glúten de trigo foram preparados em diferentes valores de pH e concentrações de glúten, etanol e glicerol. Seus efeitos sobre permeabilidade ao vapor de água e oxigênio, solubilidade em água, força de tensão e porcentagem de elongação foram avaliados usando-se a Metodologia de Superfície de Resposta. Menor permeabilidade ao oxigênio foi observada em menores concentrações de glicerol, glúten e etanol. As propriedades mecânicas foram principalmente afetadas pelas concentrações de glúten e glicerol e o filme mais resistente foi obtido quando maior concentração de glúten e menor de glicerol foram utilizadas. Coberturas de glúten de trigo aplicadas em morangos frescos reduziram as perdas de firmeza e de peso durante a estocagem em comparação com controle não revestido. Abstract Films from wheat gluten were prepared with different pH values and concentrations of gluten, ethanol and glycerol. Their effects on oxygen and water vapor permeabilities, water solubility, tensile strength and percent elongation at break were evaluated using Response Surface Methodology. The lowest oxygen permeability would be expected at low concentrations of glycerol, gluten and ethanol. The mechanical properties were mainly affected by gluten and glycerol concentrations and the most resistant film was obtained at high gluten and low glycerol concentrations. Wheat gluten coating applied to fresh strawberries reduced weight and firmness losses during storage as compared to uncoated controls.

scholarly journals Oxygen Barrier Properties and Melt Crystallization Behavior of Poly(ethylene terephthalate)/Graphene Oxide Nanocomposites

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Anna Szymczyk ◽  
Sandra Paszkiewicz ◽  
Iwona Pawelec ◽  
Sławomir Lisiecki ◽  
Marek Jotko ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Ethylene Terephthalate ◽  
Oxygen Permeability ◽  
Barrier Properties ◽  
Nanocomposite Films ◽  
Oxygen Barrier ◽  
Melt Crystallization ◽  
Nonisothermal Crystallization ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene

Poly(ethylene terephthalate) nanocomposites with low loading (0.1–0.5 wt%) of graphene oxide (GO) have been prepared by usingin situpolymerization method. TEM study of nanocomposites morphology has shown uniform distribution of highly exfoliated graphene oxide nanoplatelets in PET matrix. Investigations of oxygen permeability of amorphous films of nanocomposites showed that the nanocomposites had better oxygen barrier properties than the neat PET. The improvement of oxygen permeability for PET nanocomposite films over the neat PET is approximately factors of 2–3.3. DSC study on the nonisothermal crystallization behaviors proves that GO acts as a nucleating agent to accelerate the crystallization of PET matrix. The evolution of the lamellar nanostructure of nanocomposite and neat PET was monitored by SAXS during nonisothermal crystallization from the melt. It was found that unfilled PET and nanocomposite with the highest concentration of GO (0.5 wt%) showed almost similar values of the long period (L=11.4 nm for neat PET andL=11.5 nm for PET/0.5GO).

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