Influence of shear flow on the preparation of polymer layered silicate nanocomposites

Homminga, Douwe; Goderis, Bart; Hoffman, Sven; Reynaers, Harry; Groeninckx, Gabriël

doi:10.1016/j.polymer.2005.07.059

Cited by 83 publications

(58 citation statements)

References 24 publications

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“…Estudos com nanocompósitos de poli(butileno tereftalato) com argila [29] concluíram que é possível correlacionar o valor do índice da Lei das Potências, n, com o grau de dispersão da nanoargila na matriz Estes resultados corroboram com os resultados obtidos por difração de raio X, e evidencia a importância do estudo da sequência de mistura na busca de maiores interações entre a matriz orgânica e a carga inorgânica. Além da sequência de mistura outros fatores são muito importantes para a produção de nanocompósitos intercalados e/ou esfoliados de polietileno/argila, como a influencia do cisalhamento na obtenção dos nanocompósitos e a compatibilidade da matriz polimérica e da carga inorgânica [30] , as forças de cisalhamento facilitam a quebra dos aglomerados grandes, enquanto que a extensão da esfoliação das nanocargas é determinada mais pela compatibilidade entre a matriz polimérica e as camadas da argila, do que pelas forças de cisalhamento.…”

Section: Caracterização Estruturalunclassified

Caracterização estrutural de nanocompósitos de blendas HDPE/LLDPE e OMMT obtidos por diferentes sequências de mistura

2012

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de cinco sequências de mistura na formação da microestrutura dos nanocompósitos foi estudado. A caracterização estrutural foi realizada por análises de difração de raio X de alto ângulo (WAXD), microscopia eletrônica de transmissão (MET) e comportamento reológico em regime permanente de deformação. Os resultados mostraram que a formação da microestrutura depende da ordem de mistura dos componentes e a utilização de mistura de dois agentes compatibilizantes miscíveis com os constituintes da matriz auxiliou na distribuição da polaridade, facilitando a dispersão das nanoargilas por toda a matriz. Dentre as sequências estudadas, as que a nanoargila foi primeiramente misturada com componentes de menor viscosidade e cristalinidade (LLDPE e/ou LLDPE-g-MA) apresentaram melhor dispersão e distribuição da nanoargila na blenda polimérica. Palavras-chave: Nanocompósitos, HDPE/LLDPE, sequência de mistura. Structural Characterization of HDPE/LLDPE and OMMT Blend-Based Nanocomposites Obtained by Different Blending SequencesAbstract: High density polyethylene/linear low density polyethylene (HDPE/LLDPE) blend-based nanocomposites were prepared in a torque rheometer, using a mixture of HDPE-g-MA and LLDPE-g-MA both containing 1% of maleic anhydride as compatibilizer system. The effect from five blending sequences on the microstructure of the nanocomposites was investigated. The structural characterization was performed through wide angle X-ray diffraction (WAXD), transmission electron microscopy (TEM) and rheological properties. The results showed that the formation of morphology is dependent on the sequence of nanocomposite preparation and that the use of a mixture of two compatibilizer agents, miscible with both components of the blend matrix, facilitated the dispersion of the nanoclay throughout the matrix. The blending sequence where the nanoclay was first mixed with components of lower viscosity and crystallinity (LLDPE and/or LLDPE-g-MA) yielded better distribution and dispersion of nanoclay in the polymer blend. Keywords: Nanocomposites, HDPE/LLDPE, blend sequence. IntroduçãoPoliolefinas, como polietilenos e polipropileno, são amplamente utilizadas em aplicações para embalagens, no setor automotivo e elétrico, onde as propriedades de resistência térmica, mecânica e de permeação a gases possuem grande importância. As propriedades finais dos produtos obtidos a partir de poliolefinas estão intimamente relacionadas à morfologia desses materiais desenvolvida durante o processamento. A grande versatilidade de uso e baixo custo das poliolefinas têm gerado grande interesse tecnológico e científico, principalmente na obtenção de blendas HDPE/LLDPE [1][2][3][4][5][6] . O processamento de HDPE com baixo índice de fluidez é dificultado devido a elevada viscosidade do fundido. A adição de um material com estrutura química semelhante como o LLDPE, com alto índice de fluidez, auxilia no processamento, reduzindo a viscosidade do fundido.Dentre as alternativas utilizadas para melhorar o desempenho mecânico e de barreira das poliolefinas, ...

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Section: Caracterização Estruturalunclassified

Caracterização estrutural de nanocompósitos de blendas HDPE/LLDPE e OMMT obtidos por diferentes sequências de mistura

2012

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“…This advantage could have a significant impact on alleviating concerns about the environmental impact of plastic packaging by reducing pack weight as well as the energy required to process and transport it. Despite the huge research interest in polymer-clay nanocomposites, studies on the processing of these materials have been largely confined to the effects of extrusion conditions (shear flow) on the melt processed polymer-clay structure and properties [2][3][4][5].…”

Section: Introductionmentioning

confidence: 99%

“…A key observation in some of this work has been that shear flow may have a negligible effect on the exfoliation of clay if the polymer-clay affinity is low [3]. This is important in packaging where polyolefins and other non polar polymers play a major role.…”

Section: Introductionmentioning

confidence: 99%

The effect of temperature and strain rate on the deformation behaviour, structure development and properties of biaxially stretched PET–clay nanocomposites

Shen

Harkin‐Jones

Hornsby

et al. 2011

Composites Science and Technology

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. The effect of temperature and strain rate on the deformation behaviour, structure development and properties of biaxially stretched PET-clay nanocomposites. Composites Science and Technology, Elsevier, 2011, 71 (5), pp.758. <10.1016/j.compscitech.2011.01.024>. Accepted ManuscriptThe effect of temperature and strain rate on the deformation behaviour, structure development and properties of biaxially stretched PET-clay nanocomposites This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. UK AbstractThe inclusion of a synthetic fluoromica clay in PET affects its processability via biaxial stretching and stretching temperature (95 °C and 102 °C) and strain rate (1 s -1 and 2 s -1 )influence the structuring and properties of the stretched material. The inclusion of clay has little effect on the temperature operating window for the PET-clay but it has a major effect on deformation behavior which will necessitate the use of much higher forming forces during processing. The strain hardening behavior of both the filled and unfilled materials is well correlated with tensile strength and tensile modulus. Increasing the stretching temperature to reduce stretching forces has a detrimental effect on clay exfoliation, mechanical and O 2 barrier properties. Increasing strain rate has a lesser effect on the strain hardening behavior of the PET-clay compared with the pure PET and this is attributed to possible adiabatic heating in the PET-clay sample at the higher strain rate. The Halpin-Tsai model is shown to accurately predict the modulus enhancement of the PET-clay materials when a modified particle modulus rather than nominal clay modulus is used.

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“…Their results point to the difficulty of the genera-tion of nanocomposites using melt compounding when the interfacial properties between the polymer melt binder and the organoclay are not favorable. The effect of shear field on the morphology of nanocomposite has been reported by Homminga et al [6]. They found the shear forces can facilitate the break-up of large-sized agglomerates, whereas the extent of further exfoliation of the mineral layers is determined by the compatibility between the polymer matrix and the mineral layers rather than shear forces.…”

Section: Introductionmentioning

confidence: 81%

Evaluating the effect of processing conditions and organoclay content on the properties of styrene-butadiene rubber/organoclay nanocomposites by response surface methodology

Ghasemi

Karrabi²,

Mohammadi³

et al. 2010

Express Polym. Lett.

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Abstract. In this work, basic mathematical models and response surface graphs have been used to illustrate the relationship between mixing parameters in internal mixer and properties of the SBR (styrene butadiene rubber)/organoclay composites. Using a Box-Behnken statistical design experiment methodology, the effects of mixing temperature (80-140°C), mixing time (4-12 min) and nano filler amount (3-9 phr) in SBR nanocomposites on the properties (tensile properties, scorch time and Mooney viscosity) were evaluated. It was found that the mixing parameters (time and temperature) have the predominant role in properties and morphology of nanocomposite. The R 2 values (the R 2 values indicate the degree of agreement between the experimental results with those predicted by model) of all responses were above 0.85. Increasing temperature and mixing time facilitated a better organoclay dispersion which resulted in a better tensile property. With increase in nanoclay amount in composite the scorch time and Mooney viscosity decreased. The morphology of nanocomposite was studied by XRD (X-ray diffraction) and TEM (Transmission electron microscope). Intercalation and exfoliation of the nanoclay were observed for samples with higher temperature and longer mixing time. Due to thermal degradation of the rubber matrix at 140°C, tensile properties of the nanocomposite were decreased.

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Influence of shear flow on the preparation of polymer layered silicate nanocomposites

Cited by 83 publications

References 24 publications

Caracterização estrutural de nanocompósitos de blendas HDPE/LLDPE e OMMT obtidos por diferentes sequências de mistura

Caracterização estrutural de nanocompósitos de blendas HDPE/LLDPE e OMMT obtidos por diferentes sequências de mistura

The effect of temperature and strain rate on the deformation behaviour, structure development and properties of biaxially stretched PET–clay nanocomposites

Evaluating the effect of processing conditions and organoclay content on the properties of styrene-butadiene rubber/organoclay nanocomposites by response surface methodology

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