Influence of physical state of intercalating agents on intercalation process of high speed airflow pretreated montmorillonite in supercritical carbon dioxide

He, Wentao; Xu, Chunye; Qin, Shuhao; Yu, Jianxing; He, Min; Yao, Yong; Zhang, Qin

doi:10.1016/j.apt.2014.07.008

Cited by 7 publications

(6 citation statements)

References 23 publications

(30 reference statements)

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“…This is probably because THTDP was an ionic liquid and was in liquid state at the room temperature; besides, high‐pressure CO 2 can reduce the viscosity of the ionic liquids by dissolving into the ionic liquids. Therefore, the liquid TDTHP can freely diffuse into the gallery of clay in the presence of CO 2 , and intercalation with high degrees of exchange between TDTHP and sodium cation was obtained . In general, OGMMTs have a higher basal spacing than OMMTs, probably because silane also plays an important role in the cation exchange reaction between Na + in MMT and THTDP in these reactive media.…”

Section: Resultsmentioning

confidence: 99%

“…Hawkins reported that water molecules could penetrate into the silicate layers of clay to force the unit cells to swell, facilitating the cation exchange between surfactant molecules and the silicate layers. He et al explored the effect of supercritical carbon dioxide (scCO 2 ) on basal spacing and surface morphology of sodium MMT that were modified by using myristyltrimethylammonium bromide and tetradecyltrihexylphosphonium chloride as intercalating agents and observed more dispersed structures after treatment in scCO 2 when compared with unprocessed MMT. These observations are derived by the different systems used, and hence, by the different synergistic relationships in clay, the surfactant, and the reaction media.…”

Section: Introductionmentioning

confidence: 99%

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Effect of reaction media on clay dispersion and mechanical properties in poly(butylene succinate)/organoclay nanocomposites

Tian

Qin

Long

et al. 2015

Vinyl Additive Technology

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The effect of the reaction media on clay dispersion and mechanical properties in poly(butylene succinate) (PBS, a biodegradable aliphatic thermoplastic polyester)/organoclay nanocomposites was investigated in this article. The results suggested that the most dispersed structures can be observed for organoclay modified in supercritical carbon dioxide (scCO 2 ), which was used as solvent in the modification of montmorillonite in this study known for its environmentally benign, inexpensive, and nonflammable solvent, high diffusivity like a gas, near-zero surface tension, low viscosity and density like a liquid, and high-solvency power tunable by adjusting pressure and then organoclay modified in ethanol, while the least for organoclay was modified in distilled water. The results also confirmed intercalation-predominate structures were obtained for nanocomposites of PBS with organoclay modified in ethanol, the mixture of intercalated and exfoliated structures for nanocomposites of PBS with organoclay modified in distilled water, but when clay was modified in scCO 2 , exfoliation-predominate structures were observed for the nanocomposites. The storage modulus was significantly enhanced below the glass transition temperature, and the glass transition temperature shifted to a higher temperature compared with pure PBS and the maximum for PBS-based nanocomposite of pretreated grafted montmorillonite via modification with trihexyltetradecylphosphonium chloride in scCO 2 (OGMMTc). The mechanical properties including tensile strength and notched impact strength first decreased and then increased, whereas flexural strength and flexural modulus steadily and nearly linearly increased, maximum for PBS/OGMMTc nanocom-posite, owing to the strong interaction between matrix and clay, which ultimately led to better overall dispersion. J. VINYL ADDIT. TECHNOL., 22:423-432, 2016.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effect of reaction media on clay dispersion and mechanical properties in poly(butylene succinate)/organoclay nanocomposites

Tian

Qin

Long

et al. 2015

Vinyl Additive Technology

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“…Generally, the clay layers are organically treated to make them more compatible with the matrix before melt blending. The organic modifier, generally the alkyl ammonium salts, are thermally unstable and decompose usually from ∼200°C , which is lower than most engineering polymer degradation temperatures. Thus, the presence of surfactant in the clay galleries may adversely affect the thermal stability of nanocomposites.…”

Section: Resultsmentioning

confidence: 99%

Pyrolysis and flammability behavior of long (Glass fiber)‐Reinforced polyamide 6 by aluminum alkylphosphinate‐based flame retardants in combination with organic montmorillonite

Zhu

Zhang

et al. 2015

Vinyl Additive Technology

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The pyrolysis and flammability behavior of long (glass fiber)‐reinforced polyamide 6 containing aluminum alkylphosphinate‐based flame retardant in conjunction with montmorillonite or organic montmorillonite (OMMT) were investigated by using thermal gravimetry, limiting oxygen index, vertical burning test, and cone calorimeter measurements. The results revealed that the incorporation of OMMT in (aluminum alkylphosphinate)‐containing long (glass fiber)‐reinforced polyamide 6 did not significantly affect the thermal stability; however, they showed an obvious synergy on the char yield. The components from the flame retardant, especially phosphorus, acted in the gas phase and condensed phase simultaneously. Substitution of part of flame retardants with OMMT helped keep more phosphorus in the solid phase at the expense of gas‐phase activity, as demonstrated in scanning electron microscopy‐energy‐dispersive X‐ray characterization of the residue. This substitution constructed an impermeable barrier on the burning surface, which was responsible for the improvements in the vertical burning test classification and limiting oxygen index test. J. VINYL ADDIT. TECHNOL., 24:27–36, 2018. © 2015 Society of Plastics Engineers

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“…Therefore, the THTDP molecules can freely diffuse into the gallery of clay in the presence of CO 2 , and intercalation with high degrees of exchange between THTDP cation and Na þ was obtained. 19 The scanning electron microscopy (SEM) results provided important information about the morphology of the clay particles before and after modified processing, as shown in Figure 3. SEM images of the pristine MMT (Figure 3(a)) showed large tightly bound tactoids, which were aligned to form ellipsoid-shaped agglomerations.…”

Section: Structure Of Unmodified and Modified Mmtmentioning

confidence: 99%

Morphology and mechanical properties of polypropylene/ethylene acrylic acid/maleic anhybride-grafted polypropylene/organoclay nanocomposites

Tian

Qin

et al. 2016

Journal of Thermoplastic Composite Materials

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Polypropylene (PP)/ethylene acrylic acid (EAA)/maleic anhybride-grafted PP (PP-g-MA)/ organoclay nanocomposites were prepared using the melt mixing technique, and PP-g-MA and EAA were employed as the compatibilizers. The sodium montmorillonite (MMT) were pretreated with high-speed airflow pulverization method and then grafted using -glycidoxypropyltrimethoxysilane, followed by modification using trihexyltetradecylphosphonium chloride cation with supercritical carbon dioxide as the reaction medium (the obtained product was abbreviated as OGMMT). The modification of MMT was characterized by thermogravimetric analysis, X-ray diffraction (XRD), and scanning electron microscopy. The effect of organoclay content on microstructure and mechanical properties of PP/EAA/PP-g-MA/OGMMT Downloaded from nanocomposites was investigated by XRD, transmission electron microscopy, dynamic mechanical analysis, tensile strength, notched impact strength, flexural strength, and flexural modulus. The results show that the OGMMT has a high weight loss, a large d-spacing increment, and exfoliation predomination structure. The addition of compatibilizers benefited the formation of exfoliated structure and the dispersion of OGMMT in PP matrix, and hence, enhanced the storage modulus (G 0 ) below the glass transition temperature (T g ), storage modulus (G 00 ), T g , tensile strength, flexural strength, and flexural modulus of the nanocomposites. Furthermore, with the increasing OGMMT content, the nanocomposites exhibited very inconsiderable alteration in the clay dispersion level and enhanced G 0 below the T g , G 00 , tensile strength, flexural strength, and flexural modulus of the nanocomposites, whereas the T g was invariant. As a whole, the introduction of compatibilizers and OGMMT led to the reduction of notched impact strength, which also nearly linearly decreased with increasing clay content.

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Influence of physical state of intercalating agents on intercalation process of high speed airflow pretreated montmorillonite in supercritical carbon dioxide

Cited by 7 publications

References 23 publications

Effect of reaction media on clay dispersion and mechanical properties in poly(butylene succinate)/organoclay nanocomposites

Effect of reaction media on clay dispersion and mechanical properties in poly(butylene succinate)/organoclay nanocomposites

Pyrolysis and flammability behavior of long (Glass fiber)‐Reinforced polyamide 6 by aluminum alkylphosphinate‐based flame retardants in combination with organic montmorillonite

Morphology and mechanical properties of polypropylene/ethylene acrylic acid/maleic anhybride-grafted polypropylene/organoclay nanocomposites

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