Molecular orientation of extruded PET/LCP blend films. II. X‐ray pole figures

Branciforti, Márcia Cristina; Silva, Lucineide Balbino da; Machado, R.; Bretas, Rosário Elida Suman

doi:10.1002/app.26780

Cited by 3 publications

(2 citation statements)

References 37 publications

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“…The flow‐induced crystallization of a polymer occurs when fibrillar nucleus are formed by chain orientation. The higher the deformation rate, the higher the chain orientation52, 53; when nanoclay lamellas are present, it has also been shown54 that, once the nanoclay's lamellas are aligned along the flow, the local shear rate is enhanced, in which is called a ‘‘shear amplification mechanism.’’ Therefore, it is expected that once the nanoclay's lamellas are aligned along the flow, the chain orientation of the PTT macromolecules will further increased.…”

Section: Resultsmentioning

confidence: 99%

Study of the quiescent and shear‐induced crystallization kinetics of intercalated PTT/MMT nanocomposites

Favaro

Rego

Branciforti

et al. 2009

J Polym Sci B Polym Phys

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An intercalated nanocomposite made of montmorillonite nanoclay, MMT, and poly(trimethylene terephthalate), PTT, was produced by twin screw extrusion and characterized by wide angle X‐ray diffraction, WAXD, and transmission electron microscopy, TEM. The quiescent isothermal and non‐isothermal and the flow‐induced crystallization of the nanocomposite were studied by differential scanning calorimetry, DSC, polarized light optical microscopy, PLOM, and rheometry. The quiescent results showed that the nanoclay acted as an efficient nucleating agent for the PTT, which result in an anticipation of the transition temperature between regimes II and III of crystallization. The fold interfacial free energy, σe, of the PTT in the nanocomposite during regime III was lower than in the pure state; that is, the pure PTT developed spherulites, whereas in the nanocomposite it produced a paracrystalline morphology. Under shear rate, the total times for crystallization in the nanocomposite were higher than in the pure PTT. In flow‐induced crystallization, a fibrillar nucleus must be formed as a result of chain orientation. In the nanocomposite, chain orientation only occurred after the percolated structure was broken. Therefore, the formation of a fibrillar nucleus in the nanocomposite took more time, which increased the total crystallization time. Inc. J Polym Sci Part B: Polym Phys 48: 113–127, 2010

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Section: Resultsmentioning

confidence: 99%

Study of the quiescent and shear‐induced crystallization kinetics of intercalated PTT/MMT nanocomposites

Favaro

Rego

Branciforti

et al. 2009

J Polym Sci B Polym Phys

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“…Thus, the objective of the first part of this series is to correlate the influence of the processing parameters with the crystalline biaxial orientation of blown films of LLDPE/LDPE blends as measured by IR and to correlate this orientation with the mechanical properties of the films. The second part of this series5 will report the measurement of the crystalline and amorphous biaxial orientation of these films by X‐ray pole figures. The correlation between the rheological properties, morphology, and optical properties of these films was published in a recent article 6…”

Section: Introductionmentioning

confidence: 99%

Correlations between processing parameters, morphology, and properties of blown films of linear low‐density polyethylene/low‐density polyethylene blends. I. Crystalline biaxial orientation by IR and mechanical properties

Branciforti

Pimentel

Bernardi

et al. 2006

J of Applied Polymer Sci

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ABSTRACT:The change of the processing parameters of a blown film operation alters the mechanical and optical properties of the films. This work studied the influence of some of these parameters on the properties of blown films made of blends of linear low-density polyethylene (LLDPE) and LDPE. Correlations between the crystalline biaxial orientations of these films and the mechanical properties were found. The crystalline biaxial orientation was measured by IR following the Krishnaswamy approach. The a axis of the unit cell was oriented along the machine direction (MD) at all LDPE concentrations, and it was not affected by the blow-up ratio (BUR). In contrast, the b axis changed its orientation from orthogonal to MD to along the transverse direction (TD), and it was affected by the BUR. Finally, the c axis changed its orientation from equiplanar between the MD and TD to along the thickness of the film, and it was influenced by the BUR. The decrease of the tensile mechanical properties along the MD with the increase in the amount of LDPE in the blends was attributed to the tilting of the c axis toward the film thickness.

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Polyethylene terephthalate composite and foam with superior mechanical properties from the synergistic simultaneous in situ fibrillation of liquid crystal polymer and polytetrafluoroethylene

Jiang,

Mi,

et al. 2024

J Mater Sci

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Molecular orientation of extruded PET/LCP blend films. II. X‐ray pole figures

Cited by 3 publications

References 37 publications

Study of the quiescent and shear‐induced crystallization kinetics of intercalated PTT/MMT nanocomposites

Study of the quiescent and shear‐induced crystallization kinetics of intercalated PTT/MMT nanocomposites

Correlations between processing parameters, morphology, and properties of blown films of linear low‐density polyethylene/low‐density polyethylene blends. I. Crystalline biaxial orientation by IR and mechanical properties

Polyethylene terephthalate composite and foam with superior mechanical properties from the synergistic simultaneous in situ fibrillation of liquid crystal polymer and polytetrafluoroethylene

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