Water barrier properties of polyamide 12/montmorillonite nanocomposite membranes: Structure and volume fraction effects

Alexandre, B.; Langévin, D.; Médéric, Pascal; Aubry, Thierry; Couderc, H.; Nguyen, Quang Trong; Saiter, Allisson; Marais, Stéphane

doi:10.1016/j.memsci.2008.12.004

Cited by 178 publications

(143 citation statements)

References 60 publications

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“…This result is confirmed in the literature [3,5] and explained by the fact that minerals are modified by exchanging initial sodium ions with bigger alkylammoniums in order to change the clay polarity and pre-exfoliate the layers. The difference between the two non-modified clays may be explained by the different origins of the minerals and by the moisture content (due to the structural difference of RawMMT).…”

Section: X-ray Diffractionsupporting

confidence: 86%

“…Such a dispersion leads to high T g in spite of an eventual plasticizing effect provided by alkylammoniums. Indeed, some authors reported that T g of PA12/OMMT nanocomposites is independent of the clay content [5] because the mobility restriction is notably counterbalanced by the water plasticization. Moreover, a decrease of the nanocomposite glass transition, justified by a plasticizing effect attributed to the alkylammonium ions modifying the clay, is also reported when the mineral content increases [3].…”

Section: Analysis Of Peba/clay Nanocomposites Propertiesmentioning

confidence: 99%

“…Henceforth, different kind of polyamides (PA) or polyamide copolymers have been identified as suitable matrices for the elaboration of polymer/clay nanocomposites [2][3][4][5], bearing favorable polar amide functions along the backbone. Most of the studies dealing with PA/clay nanocomposites recourse to organically modified clay to successfully disperse the nanoplatelets.…”

Section: Introductionmentioning

confidence: 99%

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Efficient one-step melt-compounding of copolyetheramide/pristine clay nanocomposites using water-injection as intercalating/exfoliating aid

Touchaleaume¹,

Soulestin²,

Sclavons³

et al. 2011

Express Polym. Lett.

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Abstract. Polyether-block-amide (PEBA) /clay nanocomposites were prepared water-assisted by twin-screw extrusion. Both organomodified and pristine (i.e. purified but non-modified) montmorillonite clays were used. A high-pressure differential scanning calorimetry analysis carried out in the processing conditions demonstrated that PEBA/water blend exhibits some miscibility and that amide blocks and water behave as a single phase. In addition to a significant decrease of the melting temperature, water injected into the melt plays a key role among the filler dispersion and prevents the matrix from degradation during melt-extrusion. This process enables the compounding of pristine clay-based nanocomposites whose dispersion state is high enough for the resulting mechanical performances in tension to be at least equivalent to what is reached with organomodified clay. Effects of the nanofiller dispersion onto the macromolecules' mobility are detailed and fracture mechanisms are identified for the various structures.

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Section: X-ray Diffractionsupporting

confidence: 86%

Section: Analysis Of Peba/clay Nanocomposites Propertiesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Efficient one-step melt-compounding of copolyetheramide/pristine clay nanocomposites using water-injection as intercalating/exfoliating aid

Touchaleaume¹,

Soulestin²,

Sclavons³

et al. 2011

Express Polym. Lett.

View full text Add to dashboard Cite

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“…The aim and the novelty of this work is to produce new composite materials able to exploit all the aforementioned advantages of thermoplastic composites, as well as combine good mechanical properties and thermal energy storage/release capability. PA12 was chosen as a matrix because, due to a relatively high methylene/amide ratio (11/1), it presents a lower moisture sensitivity and a lower melting temperature than the more common PA6 and PA66 [53][54][55]. Additionally, there are many examples in the literature of PA12 reinforced with continuous and discontinuous glass fibers [49,[56][57][58][59].…”

Section: Introductionmentioning

confidence: 99%

Multifunctional glass fiber/polyamide composites with thermal energy storage/release capability

Fredi¹,

Dorigato²,

Pegoretti³

2018

Express Polym. Lett.

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Abstract. Thermoplastic composite laminates with thermal energy storage (TES) capability were prepared by combining a glass fabric, a polyamide 12 (PA12) matrix and two different phase change materials (PCMs), i.e. a paraffinic wax microencapsulated in melamine-formaldehyde shells and a paraffin shape stabilized with carbon nanotubes. The melt flow index of the PA12/PCM blends decreased with the PCM concentration, especially in the systems with shape stabilized wax. Differential scanning calorimetry showed that, for the matrices with microcapsules, the values of enthalpy were approximately the 70% of the theoretical values, which was attributed to the fracture of some microcapsules. Nevertheless, most of the energy storage capability was preserved. On the other hand, much lower relative enthalpy values were measured on the composites with shape stabilized wax, due to a considerable paraffin leakage or degradation. The subsequent characterization of the glass fabric laminates highlighted that the fiber and void volume fractions were comparable for all the laminates except for that with the higher amount of shape stabilized wax, where the high viscosity of the matrix led to a low fiber volume fraction and higher void content. The mechanical properties of the laminates were only slightly impaired by PCM addition, while a more sensible drop of the elastic modulus, of the stress at break and of the interlaminar shear strength could be observed in the shape stabilized wax systems.

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“…Os valores de coeficiente de permeabilidade dos nanocompósitos foram calculados e utilizados para a aplicação do modelo de Nielsen, permitindo a determinação da razão de aspecto α (Tabela 5). Para isto, primeiramente foi necessário determinar para cada composição a fração volumétrica φ, calculada com base na fração inorgânica de argila e na massa específica da argila não modificada (2,86 g/cm 3 ) [24] . Para ambos os parâmetros, coeficiente de permeabilidade e razão de aspecto, nenhum dos fatores avaliados foi estatisticamente significativo.…”

Section: Permeabilidade E Modelo De Nielsenunclassified

Influência das condições de mistura e dos teores de Acetato de Vinila e de argila nas propriedades de nanocompósitos de EVA/montmorilonita organofílica

et al. 2014

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Resumo: O copolímero Etileno Acetato de Vinila (EVA) é uma poliolefina utilizada principalmente em filmes para embalagens, onde a sua flexibilidade, tenacidade, elasticidade e transparência são atributos desejáveis. As propriedades mecânicas, térmicas e de barreira do EVA podem ser melhoradas pela incorporação de cargas inorgânicas. O EVA apresenta polaridade variável de acordo com o teor de Acetato de Vinila, o que promove a viabilidade para obtenção de nanocompósitos com argilas organicamente modificadas, tornando desnecessária a adição de agentes compatibilizantes. Neste trabalho foram preparados nanocompósitos de EVA e montmorilonita organofílica comercial pelo método de intercalação do fundido em um reômetro de torque, com rotores tipo roller, a 150°C durante 10minutos, com monitoramento do torque em função do tempo. A fim de investigar a influência da polaridade do EVA, da concentração da argila e das condições de processamento nas características dos nanocompósitos, variou-se a concentração de Acetato de Vinila (19% e 28%), o teor de argila (2% e 5%) e a velocidade de rotores (60 rpm e 100 rpm). Foram avaliadas a estrutura da argila, a estabilidade térmica e as propriedades mecânicas e de barreira dos nanocompósitos, mediante as técnicas de difração de raios X, análise termogravimétrica, ensaio de tração e análises de taxa de permeabilidade ao oxigênio e ao vapor d'água. A partir dos dados de permeabilidade foi aplicado o modelo de Nielsen para avaliar o grau de esfoliação da argila. Dentre os principais resultados com o planejamento fatorial destacam-se: (a) o aumento da polaridade do EVA aumentou a permeabilidade ao oxigênio e ao vapor d'água dos materiais; (b) o teor de argila não modificou a estabilidade térmica dos nanocompósitos e a estrutura da argila; (c) o aumento da concentração da argila aumentou o módulo elástico, reduziu a deformação de ruptura e reduziu significativamente o coeficiente de permeabilidade ao oxigênio e ao vapor d'água; (d) o fator rotação não implicou em alterações significativas em nenhuma das respostas avaliadas. Palavras-chave: Nanocompósitos, EVA, permeabilidade, montmorilonita organofílica. Influence of Processing and Content of Vinyl Acetate on the Properties of Eva/ Organophilic Montmorillonite NanocompositesAbstract: The copolymer Ethylene Vinyl Acetate (EVA) is a polyolefin used mainly in packaging films, where its flexibility, toughness, elasticity and transparency are desirable attributes. The mechanical, thermal and barrier properties of EVA can be improved by the incorporation of inorganic fillers. Its polarity varies according to the content of Vinyl Acetate, which allows for nanocomposites to be obtained with organically modified clay, with no need to add compatibilizing agents. In this work nanocomposites of EVA and commercial organophilic montmorillonite were prepared by melt intercalation in a torque rheometer with rotors roller type, at 150°C for 10 minutes, monitoring the torque versus time. The concentration of Vinyl Acetate (19% and 28%), clay content (2%...

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Water barrier properties of polyamide 12/montmorillonite nanocomposite membranes: Structure and volume fraction effects

Cited by 178 publications

References 60 publications

Efficient one-step melt-compounding of copolyetheramide/pristine clay nanocomposites using water-injection as intercalating/exfoliating aid

Efficient one-step melt-compounding of copolyetheramide/pristine clay nanocomposites using water-injection as intercalating/exfoliating aid

Multifunctional glass fiber/polyamide composites with thermal energy storage/release capability

Influência das condições de mistura e dos teores de Acetato de Vinila e de argila nas propriedades de nanocompósitos de EVA/montmorilonita organofílica

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