PP/clay nanocomposites: A study of crystallization and dynamic mechanical behavior

Hambir, Sangeeta; Bulakh, Neelima; Kodgire, Pravin; Kalgaonkar, Rajendra; Jog, J. P.

doi:10.1002/1099-0488(20010215)39:4<446::aid-polb1017>3.0.co;2-8

Cited by 129 publications

(84 citation statements)

References 13 publications

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“…In some extreme cases, crystallites grow in one dimension and a fibrous crystalline morphology can be observed. [12] That's why the Ozawa model is not valid for PTT/25A nanocomposites and the m decreases as the temperature decreases. The similar trend of n to m as a function temperature may be related to similar reasons.…”

Section: Resultsmentioning

confidence: 58%

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Non‐Isothermal Crystallization of Poly(trimethylene terephthalate) (PTT)/Clay Nanocomposites

Lesser

2004

Macro Chemistry & Physics

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Summary: The non‐isothermal crystallization of intercalated poly(trimethylene terephthalate) (PTT)/clay nanocomposites was investigated quantitatively by different methods. Non‐isothermal crystallization of pure PTT can be described by the Ozawa equation, but the Ozawa theory is not valid for PTT/clay nanocomposites. The addition of clay into PTT decreases the crystallization half‐time while increasing the crystallinity and crystallization rate. The PTT/modified clay nanocomposites, in turn, have a higher crystallization rate parameter, k1/n, and a lower crystallization half‐time compared to unmodified clay/PTT composites. The crystallization activation energy, calculated from Kissinger equation, of PTT, PTT/unmodified clay, and PTT/modified clay composites are 100, 180, and 198–230 kJ · mol−1, respectively. Similarly, the nucleating activities of the unmodified clay and modified clays are 0.73 and 0.51–0.58, respectively. Although the addition of clay increases the crystallization activation energy, the clay still acts as an effective nucleating agent and increases the crystallization rate and crystallinity of PTT. Further, the modified nanoscale clays are more effective nucleating agents than the unmodified counterparts, and the most effective nucleating concentration of nano‐clay is between 1.0–3.0 wt.‐%.The crystallization half‐time, t1/2, decreases as a function of cooling rate, Q, and decreases with an increase in clay concentration.magnified imageThe crystallization half‐time, t1/2, decreases as a function of cooling rate, Q, and decreases with an increase in clay concentration.

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Section: Resultsmentioning

confidence: 58%

“…The addition of nano-scale clays can change the crystallization kinetics, the crystalline morphology, the crystal forms, as well as crystallite size. [3][4][5][6][7][8][9][10][11][12][13] This difference in crystalline morphology, in turn, can significantly affect the overall mechanical and physical properties of the materials.…”

Section: Introductionmentioning

confidence: 99%

Non‐Isothermal Crystallization of Poly(trimethylene terephthalate) (PTT)/Clay Nanocomposites

Lesser

2004

Macro Chemistry & Physics

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“…[15][16][17] Most PE is used in film applications. These applications include food packaging, shrink films, stretch films, rubbish-bin liners, and merchandise packaging.…”

Section: Introductionmentioning

confidence: 93%

Effect of Ionomeric Compatibilizer on Clay Dispersion in Polyethylene/Clay Nanocomposites

Sánchez-Valdés

Lopez‐Quintanilla

Ramı́rez-Vargas

et al. 2006

Macro Materials & Eng

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Summary: Linear low‐density polyethylene (LLDPE)/clay nanocomposites are obtained and studied by using a zinc‐neutralized carboxylate ionomer as a compatibilizer. LLDPE‐g‐MA is used as a reference compatibilizer. Two different clays, natural montmorillonite (Closite Na+) and a chemically modified clay Closite 20A have been used. Nanocomposites are prepared by melt blending in a twin‐screw extruder using two mixing methods: two‐step mixing and one‐step mixing. The relative influence of each compatibilizer is determined by wide‐angle X‐ray diffraction structural analysis and mechanical properties. The results are analyzed in terms of the effect of the compatibilizing agent and incorporation method in the clay dispersion, and the mechanical properties of the nanocomposites. Experimental results confirm that the film samples with ionomer show a good mechanical performance only slightly below that of the samples with maleic anhydride (MA). The two‐step mixing conditions result in better dispersion and intercalation for the nanofillers than one‐step mixing. The exfoliation of clay platelets leads to an improved thermal stability of the composite. The oxygen permeability of the clay nanocomposites, using ionomer as a compatibilizer, is decreased by the addition of the clay.TEM image of a PE/4 wt.‐% Closite 20A nanocomposite formed using ionomer.imageTEM image of a PE/4 wt.‐% Closite 20A nanocomposite formed using ionomer.

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“…These are twophase materials with unexpected improved properties normally unavailable with either of the conventional composites or with pure polymers. [1,2] The extensive use of clay minerals as filler in the polymer matrix strictly lies on its cheapness. [3,4] The degree of improvement of polymeric properties is extremely dependent on the degree of dispersion of aluminosilicate layers in the polymer matrix, i.e., it is directly dependent on the size of the clay particles dispersed; [5] as a result, either intercalated nanocomposites in which the polymer chains are inserted regularly in between the clay layers or delaminated nanocomposites where silicate layers are randomly dispersed in the polymer matrix or partially delaminated nanocomposites where there is the existence of both these configurations may be emerged out.…”

Section: Introductionmentioning

confidence: 99%

“…According to Alexandre et al [23] , nanocomposites were only formed when EVA was melt blended at 130 8C with nonfunctionalized organoclay. Polymer/clay nanocomposites reported so far are mainly on the synthesis and on the evaluation of mechanical, thermal barrier, dynamic mechanical, rheological properties and fire retardance, [1][2][3][4][5][11][12][13][14][15] etc. Recent studies have shown that the interaction between polymer chains and liquids is of considerable interest especially from the practical application point of view.…”

Section: Introductionmentioning

confidence: 99%

Exertion of Inhibiting Effect by Aluminosilicate Layers on Swelling of Solution Blended EVA/Clay Nanocomposite

Pramanik

Acharya

Srivastava

2004

Macro Materials & Eng

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Summary: Ethylene vinyl acetate (EVA) copolymer/dodecyl ammonium ion intercalated montmorillonite (12Me‐MMT) nanocomposites were swelled in xylene under atmospheric condition. Swelling index of these nanocomposites decreased with filler loading indicating that the solvent uptake of these nanocomposites was inversely related to the filler contents. The volume fractions of nanocomposites showed an increasing trend with filler concentration because of unswelling effect exerted by aluminosilicate layers. The cross‐link density was determined using the Flory‐Rehner equation and it was observed that the cross‐link density of these nanocomposites also showed an increasing trend with increasing filler loading. Free energy change (ΔGmix) and the change in entropy (ΔSmix) on swelling of EVA/12Me‐MMT nanocomposites in xylene were calculated and these values reaffirmed that the interaction between polymer chains and silicate layers was very strong which induced remarkable inhibiting ability on EVA matrix when swelled in xylene.TEM photograph of EVA/12Me‐MMT nanocomposite containing 8 wt.‐% 12Me‐MMT.magnified imageTEM photograph of EVA/12Me‐MMT nanocomposite containing 8 wt.‐% 12Me‐MMT.

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PP/clay nanocomposites: A study of crystallization and dynamic mechanical behavior

Cited by 129 publications

References 13 publications

Non‐Isothermal Crystallization of Poly(trimethylene terephthalate) (PTT)/Clay Nanocomposites

Non‐Isothermal Crystallization of Poly(trimethylene terephthalate) (PTT)/Clay Nanocomposites

Effect of Ionomeric Compatibilizer on Clay Dispersion in Polyethylene/Clay Nanocomposites

Exertion of Inhibiting Effect by Aluminosilicate Layers on Swelling of Solution Blended EVA/Clay Nanocomposite

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