| 1. |
- Liu, X. H., et al.
(author)
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Polyamide 6/clay nanocomposites using a cointercalation organophilic clay via melt compounding
- 2003
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In: Journal of Applied Polymer Science. - : Wiley. - 0021-8995 .- 1097-4628. ; 88:4, s. 953-958
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Journal article (peer-reviewed)abstract
- Polyamide 6/clay nanocomposites (PA6CN) were prepared via the melt compounding method by using a new kind of organophilic clay, which was obtained through cointercalation of epoxy resin and quaternary ammonium into Na-montmorillonite. The dispersion effect of this kind of organophilic clay in the matrix was studied by means of X-ray diffraction (XRD) and transmission electron microscopy (TEM); the silicate layers were dispersed homogeneously and nearly exfoliated in the matrix. This was probably the result of the strong interaction between epoxy groups and amide end groups of PA6. The mechanical properties and heat distortion temperature (HDT) of PA6CN increased dramatically. The notched Izod impact strength of PA6CN was 80% higher than that of PA6 when the clay loading was 5 wt%. Even at 10 wt% clay content, the impact strength was still higher than that of PA6. The finely dispersed silicate layers and the strong interaction between silicate layers and matrix decreased the water absorption. At 10 wt% clay content, PA6CN only absorbs half the amount of water compared with PA6. The dynamic mechanical properties of PA6CN were also studied.
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| 2. |
- Liu, X. H., et al.
(author)
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Polyamide 6-clay nanocompositles/polypropylene-grafted-maleic anhydride alloys
- 2001
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In: Polymer. - 0032-3861 .- 1873-2291. ; 42:19, s. 8235-8239
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Journal article (peer-reviewed)abstract
- Polyamide 6-clay nanocomposites (PA6CN) based on montmorillonite typically show some brittleness with clay addition. In order to address this problem, PA6CN/PP-g-MAH alloys were prepared through blending PA6CN with polypropylene-grafted-maleic anhydride (PP-g-MAH). The mechanical properties, dynamic mechanical temperature spectra, morphology and water absorption of the alloys were studied. Compared with PA6CN, the notched impact strength of the alloys increased greatly while the alloys still maintained higher stiffness and strength than that of PA 6. The morphological studies via scanning electron microscopy (SEM) showed a PP-g-MAH toughen phase dispersed in PA6CN matrix. As the PP-g-MAH content was increased, reduced water absorption was observed.
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| 3. |
- Liu, X. H., et al.
(author)
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Investigation on unusual crystallization behavior in polyamide 6/montmorillonite nanocomposites
- 2002
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In: Macromolecular materials and engineering. - 1438-7492 .- 1439-2054. ; 287:8, s. 515-522
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Journal article (peer-reviewed)abstract
- The crystallization behavior and crystal structure of polyamide 6/montmorillonite (PA6/MMT) nanocomposites were investigated by differential scanning calorimetry and X-ray diffraction, and an interesting behavior was observed. The material was prepared via melt compounding using an organophilic clay obtained by co-intercalation of epoxy resin and quaternary ammonium into Na-montmorillonite. A maximum in degree of crystallinity was obtained at 5 wt.-% MMT and the reasons for this, based on the MMT layer distribution, were discussed. The degree of crystallinity showed a strong dependence on the cooling rates. In contrast with typical behavior, a higher cooling rate resulted in a higher degree of crystallinity. In nanocomposites, the gamma-crystalline phase was dominant.
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