Crystallization behavior of nylon 11/montmorillonite nanocomposites under annealing

Zhang, Xikui; Yang, Guisheng; Lin, Jiaping

doi:10.1002/app.23900

Cited by 14 publications

(14 citation statements)

References 36 publications

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“…Second, one can envisage that, as for PA6, there are strong interactions between the clays surfaces and the PA11 chains which favor the formation of the α form rather than the γ one. Particularly, Zhang et al have shown that the hydrogen bonds of PA11 are weakened upon addition of clay that restricts the formation of hydrogen bonding sheets by forcing the amide groups out of the hydrogen bonding sheets 51. Moreover, VanDerHart et al have shown by means of RMN experiments that, the γ‐phase growth from the clay surface, obtains a head start on any growth of the α‐phase originating in regions away from the clay surface 52.…”

Section: Resultsmentioning

confidence: 99%

Relations between structure and property of polyamide 11 nanocomposites based on raw clays elaborated by water‐assisted extrusion

Stoclet¹,

Sclavons²,

Devaux³

2012

J of Applied Polymer Sci

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Bio-based polymers and polymer nanocomposites have known an increasing interest during the past few years. This work is focused on the elaboration and the characterization of bio-based nanocomposites made from polyamide 11 (PA11) and nonorganomodified montmorillonite. To elaborate these materials an original elaboration process, consisting in injecting water during the extrusion, was used. Results show that thanks to this process, a well exfoliated morphology is obtained for clay contents as high as 10% wt. This was explained on the one hand by the fact that the clay is soluble in water and on the other hand by the fact that water and PA11 are miscible at high pressure and high temperature. Moreover, the morphology analyses have revealed that from 10% wt of clay, the platelets were not totally randomly distributed but they were rather organized at a mesoscopic scale. The obtaining of such clay's dispersion involves an enhancement of thermomechanical properties. For example, for a clay content of 10% wt, the Young's modulus of the material can be doubled and its degradation temperature increased. The role of the elaboration conditions on the morphology and subsequent properties of the nanocomposites are also carefully analyzed. Finally, it has been evidenced that the presence of the filler infers on both the crystalline form induced and the crystallization kinetics. In summary, this study demonstrates that, in the case of PA11 nanocomposites, the water-assisted injection process leads to the achievement of an exfoliated morphology for clay contents as high as 10% wt that allows to obtain high performance materials and to be free from using organomodified clays.

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Section: Resultsmentioning

confidence: 99%

Relations between structure and property of polyamide 11 nanocomposites based on raw clays elaborated by water‐assisted extrusion

Stoclet¹,

Sclavons²,

Devaux³

2012

J of Applied Polymer Sci

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show abstract

“…Neat PA11 sample exhibits three characteristic peaks at diffraction angles of around 2θ = 7.23°, 20.23° and 23°, respectively associated to the (001), (100) and (010/110) plane, indicating the presence of the triclinic α-form of nylon 11 [6,29,30]. Unlike layered clays, whose primary diffraction peaks shift significantly to higher/lower angles when it is aggregated/exfoliated in a polymer matrix [31], the unit layer in a single rod crystal cannot be separated or delaminated, because this would imply the disruption of the silicate structure. Therefore, the characteristic diffraction peak of the PLG nanofiller, located at 2θ = 8.4°, keeps its original position even if the PLG is well dispersed in the matrix [12,18,32].…”

Section: Morphological and Structural Properties Of Pa11 Nanocompositesmentioning

confidence: 99%

Structure and Properties of Polyamide 11 Nanocomposites Filled with Fibrous Palygorskite Clay

Benobeidallah¹,

Benhamida²,

Dorigato³

et al. 2019

Journal of Renewable Materials

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Various amounts (up to 10 wt%) of palygorskite nanofibers functionalized by 3-aminopropyltriethoxysilane (APTES) coupling agent were used to reinforce polyamide 11 nanocomposites prepared by melt compounding. The covalent bonding of the silane on the palygorskite surface was confirmed by infrared spectroscopy and thermogravimetric analysis. X-ray diffraction revealed the retention of the α-form of polyamide crystals upon the addition of both natural and silane treated palygorskite nanorods. All the investigated nanocomposites showed an improvement of the thermal stability, especially when surface treated palygorskite nanofibers were considered. Tensile tests and dynamic mechanical thermal analyses on the prepared materials evidenced how the incorporation of palygorskite nanofibers significantly increased the elastic and the storage moduli of polyamide, and this enhancement was more evident when natural palygorskite nanorods were used.

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“…Zhang et al [120] have observed that the addition of MMT induced a change in the crystalline form of Nylon 11, from the pseudohexagonal δ ′ form to the more stable hexagonal δ form. This was attributed to the restricted formation of hydrogen -bond sheets, forcing the amide groups of nylon out of the hydrogenbond sheets in the presence of MMT.…”

Section: Nylon 11mentioning

confidence: 99%

Crystallization in Polymer Nanocomposites

Jog

2010

Optimization of Polymer Nanocomposite Properties

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Over the past decade, polymer nanocomposites have been a topic of great interest to research groups in both pure and applied materials science [1 -4] . These nanocomposites are two -phase materials wherein a fi ller with at least one dimension in the range of 1 to 100 nm is dispersed in the polymer matrix. Various nanofi llers such as carbon nanotube s ( CNT s), inorganic nanoparticles, or layered silicates such as clay are used. These nanocomposites show remarkable property improvements as compared to virgin polymers; moreover, this occurs at very low fi ller loadings when compared to conventional microcomposites. The properties of these nanocomposites are dependent on the morphology generated during their processing. In the case of semi -crystalline polymers, this is more crucial as the crystallization of polymers takes place during processing. A knowledge of the crystallization process, and the effect of these nanofi llers on the crystallization behavior of polymer nanocomposites, is therefore imperative to acquire an understanding of structure -property relationships in polymer nanocomposites.Crystallization in polymers has been the subject of great academic interest, as polymers are known to exhibit a variety of structures at various length scales, such as the unit -cell, lamella, and spherulites. The crystallization of polymers results in different morphologies, depending on the crystallization conditions and the presence of other components. The presence of a second phase either a polymer or a low -molecular -weight compound or inorganic fi ller has a profound effect on the crystallization of the polymer. In nanocomposites, the dimensions of the second phase are close to the chain dimensions, and a number of studies have attempted to elucidate the effect of nanosized fi llers on the crystallization kinetics, the crystalline morphology, and the crystalline forms of polymers. In this chapter, a brief review is presented of recent investigations into the effects of nanofi llers on various aspects of crystallization, such as isothermal crystallization, nonisothermal crystallization, spherulitic growth, and polymorphism.

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Crystallization behavior of nylon 11/montmorillonite nanocomposites under annealing

Cited by 14 publications

References 36 publications

Relations between structure and property of polyamide 11 nanocomposites based on raw clays elaborated by water‐assisted extrusion

Relations between structure and property of polyamide 11 nanocomposites based on raw clays elaborated by water‐assisted extrusion

Structure and Properties of Polyamide 11 Nanocomposites Filled with Fibrous Palygorskite Clay

Crystallization in Polymer Nanocomposites

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