Water absorption in EVOH films and its influence on glass transition temperature

Zhang, Zhongbin; Britt, Ian J.

doi:10.1002/(sici)1099-0488(19990401)37:7<691::aid-polb20>3.3.co;2-m

Cited by 10 publications

(14 citation statements)

References 2 publications

(2 reference statements)

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“…Water sorption depresses the glass transition temperature of polymers, which aff ects their permeability to gases (Eichler and Miltz, 1993). For ethylene vinyl alcohol, the glass transition temperature is 20 to 40°C at intermediate relative humidity (Zhang et al, 1999), suggesting that the Table 1. Temperature response of resistance to diff usion (R) of selected fi lms to fi ve fumigant compounds.…”

Section: Resistance Of a Virtually Impermeable Film Varies With Relatmentioning

confidence: 99%

A Standardized Approach for Estimating the Permeability of Plastic Films to Soil Fumigants under Various Field and Environmental Conditions

2011

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Minimizing atmospheric emissions of soil fumigants is critical for protecting human and environmental health. Covering the soil surface with a plastic tarp is a common approach to restrict fumigant emissions. The mass transfer of the fumigant vapors through the tarp is often the rate-limiting factor in fumigant emissions. An approach for standardizing measurements of film permeability is proposed that is based on determining the resistance (R) of films to diffusion of fumigants. Using this approach, values were determined for more than 200 film-chemical combinations under a range of temperature, relative humidity, and film handling conditions. Resistance to diffusion was specific for each fumigant/film combination, with the largest range of values observed for the fumigant chloropicrin. For each fumigant, decreased with increasing temperature. Changes in film permeability due to increases in temperature or field installation were generally less than a factor of five. For one film, values determined under conditions of very high relative humidity (approximately 100%) were at least 100 times lower than when humidity was very low (approximately 2%). This approach simplifies the selection of appropriate films for soil fumigation by providing rapid, reproducible, and precise measurements of their permeability to specific fumigants and application conditions.

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Section: Resistance Of a Virtually Impermeable Film Varies With Relatmentioning

confidence: 99%

A Standardized Approach for Estimating the Permeability of Plastic Films to Soil Fumigants under Various Field and Environmental Conditions

2011

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“…From the steady-state region of the curves in Figure 1 the permeability coefficient P can be calculated. 9 Permeability coefficients with respect to water vapor and O 2 were calculated at three different relative humidity (RH) values and the data are reported in Figure 2. As can be expected, the permeability to both water vapor [ Fig.…”

Section: Permeability To Water Vapor and Oxygenmentioning

confidence: 99%

“…Moreover, since it is well known that the presence of water can cause plasticization of both PA6 and EVOH, greatly affecting the barrier and mechanical properties, 9,10 the influence of the humidity content on permeability to water vapor and oxygen, and on tensile properties of the earlier-mentioned films has been investigated.…”

Section: Introductionmentioning

confidence: 99%

Thermal oxidative stability and effect of water on gas transport and mechanical properties in PA6‐EVOH films

Cerruti

Laurienzo

Malinconico

et al. 2007

J Polym Sci B Polym Phys

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The thermal oxidative stability and the effect of water on gas transport and mechanical properties of blends of polyamide 6 (PA6) with ethylene-co-vinyl alcohol (EVOH) and EVOH modified with carboxyl groups (EVOH-COOH) have been investigated. The presence of EVOH reduces water vapor and oxygen gas permeability of polyamide, as well as small amounts of EVOH-COOH further improve barrier properties, especially to oxygen. This has been explained in terms of improved interactions of the blend constituents in the amorphous phase, due to ionic linkages between the polyamide amino groups and the carboxyls of modified EVOH. The permeation to gases was found to increase with the amount of sorbed water. The morphology of the samples was found to have an effect on barrier properties, as the presence of EVOH causes the PA6 a crystalline form to increase, lowering the permeability to oxygen and water vapor. Mechanical properties are strongly affected by water sorption, as tensile modulus and strength decrease with increasing water content. Chemiluminescence (CL), infrared spectroscopy (FTIR), and tensile test were employed in order to assess the correlation between chemical composition and the thermal oxidative stability of the films aged at 110 8C in air. CL experiments suggest that the presence of EVOH and EVOH-COOH efficiently inhibits the formation of peroxidized species during the processing, and increases the thermal oxidative stability of the films. Infrared spectroscopy showed a build-up of carbonyl absorption in the range 1700-1780 cm À1 , due to the formation of oxidation products, which is greater in the case of the pure polymer. Tensile tests on films revealed a reduction in ductility as a result of ageing for neat PA6, whereas in comparison the blends exhibit a far better long-term stability. V V C 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 840-849, 2007

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“…66,67 EVOH in contact with moisture is severely plasticized, increasing its permeability and swelling properties. [68][69][70][71][72][73] This last modification could have a good interest to the final release of biocide agents.…”

Section: Introductionmentioning

confidence: 99%

“…Presently, several studies have evaluated the impact of additives on these antimicrobial properties and particularly for EVOH materials. 72,[74][75][76][77][78][79][80][81][82][83][84]…”

Section: Introductionmentioning

confidence: 99%

Antimicrobial materials based on poly(ethylene‐co‐vinyl alcohol) and silver acetate produced by reactive extrusion

Paillot

Farhat

Becquart

et al. 2019

J of Applied Polymer Sci

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The use of silver as an antimicrobial agent has exhibited great interest in recent years. In this research, poly(ethylene‐co‐vinyl alcohol) (EVOH)–silver acetate‐based antimicrobial materials were prepared at high temperature by reactive extrusion. Silver acetates were used without pretreatment. The thermal reaction of silver acetates in the material and their effect on the thermal and mechanical properties of the polymer were investigated as a function of their concentration. The dispersed silver acetate salts within the EVOH matrix have displayed a significant thermal reaction. This reaction of metallic salts was partial when the extrusion temperature was fixed at 190 °C and completed at 230 °C. The antimicrobial agents also had significant effects on the properties of the matrix. Reductions of glass temperature and storage modulus were observed by the analyses. All the variations were dependent on both the concentration of silver acetate and the extrusion parameters. The antimicrobial activity was studied and demonstrated a promising potential to create an antimicrobial material in a one‐step solvent free extrusion method. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47799.

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Water absorption in EVOH films and its influence on glass transition temperature

Cited by 10 publications

References 2 publications

A Standardized Approach for Estimating the Permeability of Plastic Films to Soil Fumigants under Various Field and Environmental Conditions

A Standardized Approach for Estimating the Permeability of Plastic Films to Soil Fumigants under Various Field and Environmental Conditions

Thermal oxidative stability and effect of water on gas transport and mechanical properties in PA6‐EVOH films

Antimicrobial materials based on poly(ethylene‐co‐vinyl alcohol) and silver acetate produced by reactive extrusion

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