Ethylene Vinyl Alcohol Resins as a Barrier Material in Multi-Layer Packages

Blackwell, Ashley

doi:10.1177/875608798500100304

Cited by 11 publications

(13 citation statements)

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“…3 A widely used oxygen barrier material is termed ethylene vinyl alcohol (EVOH), a semicrystalline polyethylene (PE) and poly(vinyl alcohol) (PVOH) copolymer made by free-radical copolymerization of ethylene and vinyl acetate, followed by deacylation. 4 The microstructure is poorly controlled, and the polymers are branched as a result of this technique. 5 While PVOH homopolymer has better oxygen barrier properties than EVOH, PVOH has poor water barrier properties and is difficult to process due to low degradation temperatures.…”

Section: ■ Introductionmentioning

confidence: 99%

Regiospecific Poly(ethylene-co-vinyl alcohol) by ROMP of 3-Acetoxycyclooctene and Postpolymerization Modification for Barrier Material Applications

Dingwell

2023

ACS Appl. Polym. Mater.

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Ethylene vinyl alcohol (EVOH) is an oxygen barrier polymer used to prevent premature degradation of food, pharmaceuticals, and other products due to its semicrystallinity, strong intermolecular interactions, and consequently low free volume. EVOH is made using traditional free-radical copolymerization, which leads to little structural regularity. We utilized ringopening metathesis polymerization (ROMP) to determine how regioregularity impacts the barrier properties of EVOH-related materials. A regioregular (head-to-tail) polymer was synthesized from ROMP of 3-acetoxycyclooctene, followed by hydrogenation and deacylation to give a linear, highly regioregular EVOH (PH3OHCOE) containing the equivalent of 75 mol % ethylene units. The same process was carried out with 5-acetoxycyclooctene, but the resulting polymer (PH5OHCOE) is regiorandom. Both polymers were compared to an industry benchmark, EVOH-44, containing 44 mol % ethylene units. After processing, differential scanning calorimetry showed that the semicrystalline PH3OHCOE had a higher melting temperature and enthalpy of melting compared to semicrystalline PH5OHCOE, indicating that PH3OHCOE is more crystalline. This was confirmed by wide-angle X-ray scattering (WAXS). WAXS, rheological studies, and polarized optical microscopy showed that PH3OHCOE has a more well-defined crystal structure, a higher degree of hydrogen-bonding between −OH groups, and a higher glass transition temperature compared to PH5OHCOE. These differences were also highlighted in their tensile behavior, where PH3OHCOE and EVOH-44 exhibited brittle failure compared to the ductile behavior observed for PH5OHCOE. Oxygen barrier testing demonstrated that regioregular PH3OHCOE had an oxygen permeability more than a factor of 3 lower than regiorandom PH5OHCOE but still higher than EVOH-44, while water barrier testing showed that PH3OHCOE had the lowest water permeability, more than 6 times lower than EVOH-44. These results highlight the importance of regioregularity on the barrier properties of EVOH-like materials and show that structural regularity can lower oxygen permeability while maintaining low water permeability at the low vinyl alcohol content.

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Section: ■ Introductionmentioning

confidence: 99%

Regiospecific Poly(ethylene-co-vinyl alcohol) by ROMP of 3-Acetoxycyclooctene and Postpolymerization Modification for Barrier Material Applications

Dingwell

2023

ACS Appl. Polym. Mater.

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“…Noticeably, the initial 5 wt% EVOH brought down the permeation significantly where diminishing improvements for EVOH concentrations above 10 wt% and 15 wt%. The WVTR slightly improved from the original 1.17 g/100 in 2 ÁdayÁatm to 0.80 g/100 in 2 ÁdayÁatm for 5% EVOH, 0.75 g/100 in 2 ÁdayÁatm for 10 wt% EVOH and 0.77 g/100 in 2 ÁdayÁatm for 15 wt% EVOH. The barrier effect of the EVOH to moisture is diminished in the LDPE/EVOH/LDPE film due to the excellent moisture barrier of the LDPE film.…”

Section: Barrier and Peel Strengthmentioning

confidence: 79%

“…However, EVOH tends to absorb moisture because of the presence of hydrophilic hydroxyl groups in its polymer structure, thus limiting its application primarily to the center of the laminates. 2 Therefore, combining LDPE and EVOH into one structure provides an ideal film structure for food packaging. The LDPE offers sealing and printing capabilities while acting as an outer layer to inhibit moisture diffusion into EVOH layer at the center.…”

Section: Introductionmentioning

confidence: 99%

Barrier, mechanical, and thermal properties of the three-layered co-extruded blown polyethylene/ethylene–vinyl alcohol/low density polyethylene film without tie layers

Lei

Aldi

2015

Journal of Thermoplastic Composite Materials

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This article investigates three-layer co-extruded blown film comprised of low-density polyethylene (LDPE)/ethylene–vinyl alcohol (EVOH)/LDPE without adhesion layers. Various thicknesses of pure EVOH were sandwiched by outer LDPE layers blended with linear low-density polyethylene-grafted-maleic anhydride (LLDPE- g-MAH) as compatibilizer in concentrations from 0 wt% to 2.0 wt%. The study found that a mere 3-μ EVOH layer can achieve a 180 times improvement of oxygen barrier properties as compared to the control sample. When the EVOH loading is 10–15 wt% of the total film mass, the addition of LLDPE- g-MAH into the outer layers indicated a positive synergistic effect by enhancing barrier properties. In contrast, when the EVOH loadings are at 5 wt% and 7.5 wt%, the barrier properties of the film was reduced. Layer-to-layer interaction between the LDPE and EVOH was notably improved as demonstrated by a 26–42% increase of interlaminate peel strength in the presence of 0.5–2 wt% LLDPE- g-MAH in all samples. Congruently, the introduction of the LLDPE- g-MAH into the outer LDPE layers also resulted in an increased dart impact toughness and tensile strength for the film. The EVOH crystallinity showed a reduction after adding LLDPE- g-MAH, particularly apparent for the lower EVOH concentrations.

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“…3 This plasticizing effect of water on the barrier properties of EVOH is, however, kinetically arrested if EVOH is protected, as in typical retortable food packaging tray designs, between hydrophobic PP and adhesive layers. 4 When such retortable packs (containing aqueous foodstuffs) are subjected to steam retorting, some water molecules find more easily their way through thermally activated chain motions of the polypropylene, sorb onto the EVOH layer, and increase the oxygen permeability of the package. The rate of water release after the retorting treatment through the outer polypropylene layer becomes very slow on cooling; so, the oxygen permeability can remain elevated for many weeks.…”

Section: Introductionmentioning

confidence: 99%

Nanocomposites of moisture-sensitive polymers and biopolymers with enhanced performance for flexible packaging applications

Lagarón

Núñez

2011

Journal of Plastic Film & Sheeting

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Ethylene-vinyl alcohol copolymers, polyamides, polyvinyl alcohol and, since more recently, some biopolymers are materials with broad applications in high-barrier packaging due to transparency and superior oxygen barrier. However, these materials suffer from strong plasticization in properties due to sorption of moisture, which handicaps their application under high-moisture conditions such as those applied in many packaging cases. This article shows the development of novel nanocomposites based on an optimized kaolinite grade, commercially marketed as O 2 Block Õ , which exhibit enhanced ultraviolet and decreased oxygen permeability, by up to 70%, as well as reduced both water permeability, by up to 50%, and sensitivity.

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Ethylene Vinyl Alcohol Resins as a Barrier Material in Multi-Layer Packages

Cited by 11 publications

References 0 publications

Regiospecific Poly(ethylene-co-vinyl alcohol) by ROMP of 3-Acetoxycyclooctene and Postpolymerization Modification for Barrier Material Applications

Regiospecific Poly(ethylene-co-vinyl alcohol) by ROMP of 3-Acetoxycyclooctene and Postpolymerization Modification for Barrier Material Applications

Barrier, mechanical, and thermal properties of the three-layered co-extruded blown polyethylene/ethylene–vinyl alcohol/low density polyethylene film without tie layers

Nanocomposites of moisture-sensitive polymers and biopolymers with enhanced performance for flexible packaging applications

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