AFM and SALS Characterization of Spherulitic Structure in Polyethylene

Viswanathan, R.; Marr, David W. M.

doi:10.1021/la950460j

Cited by 6 publications

(3 citation statements)

References 16 publications

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“…The diameter of the nodules observed in this study varied from about 15 to 55 nm. Our findings on untreated PP agree well with those of Viswanathan and Marr, who have worked with polyethylene and reported a granular structure originating from the spherulites of the polymer. The present observation of the increase in the size of the nodules with the treatment time (Figure ) indicates that etching is not the only explanation for the morphological changes.…”

Section: Discussionsupporting

confidence: 92%

Application of AFM on the Adhesion Studies of Oxygen-Plasma-Treated Polypropylene and Lignocellulosics

et al. 1999

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Atomic force microscopy was used to study the surfaces of oxygen-plasma-treated polypropylene (PP), kraft pulp, filter paper, and wood. The effect of plasma treatment on the adhesion properties between PP film and wood was evaluated by means of a peel test. The highest adhesion to wood resulted from the shortest treatment times used. The effects of plasma on the adhesion properties were more pronounced when both the PP film and the wood surface were treated. Oxygen plasma caused changes in the morphology of the materials: the treated PP surface was covered by a nodular structure, which was not seen on the untreated film. A similar nodular structure was also seen on the lignocellulosic materials. These nodules seemed to have poor interaction with the PP surface, resulting in a weak interface between the plastic film and wood.

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Section: Discussionsupporting

confidence: 92%

Application of AFM on the Adhesion Studies of Oxygen-Plasma-Treated Polypropylene and Lignocellulosics

et al. 1999

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“…From the magnified images (Figure c,d), it became evident that these regions consisted of lamellae of different orientations, labeled by letters E and F. Region E was composed of lamellae in the edge-on orientation, whereas region F consisted of twisted and orderly stacked lamellae, most of them lying flat-on. This morphology reminds us of lamellar twisting, a common phenomenon for PE and other polymers. − Lamellar twisting has been established in banded spherulites, where the band spacing depends on crystallization temperature. In the present case, the band period was not constant but varied in different regions.…”

Section: Resultsmentioning

confidence: 67%

Formation of Asymmetric Leaf-Shaped Crystals in Ultrathin Films of Oriented Polyethylene Molecules Resulting from High-Temperature Relaxation and Recrystallization

Liu

et al. 2019

Macromolecules

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We melted, annealed, and recrystallized ultrathin films of oriented polyethylene (PE) molecules prepared by melt-drawing. A large number of randomly oriented asymmetric leaf-shaped crystalline structures consisting of preferentially oriented lamellae were formed simultaneously, as observed by optical and atomic force microscopies. The structural arrangement within these leaf-shaped crystalline structures was identified by grazing incidence X-ray diffraction. These structures consisted of two distinct sections, both differing strongly from circular spherulites obtained by crystalizing an isotropic melt. Besides, regions containing groups of stacks of slightly inclined but well-aligned flat-on lamellae and regions of less orderly arranged edge-on lamellae were found. When increasing the annealing temperature and/or annealing time, a change in morphology from the leaf-shaped crystalline structures to spherulites with two symmetric "eyes" was observed. Intriguingly, the annealing times required for such a change in crystalline morphology were about four orders of magnitude longer than the longest bulk relaxation time (reptation time). Because the appearance of spherulites indicates that films became equilibrated and reached a state of an isotropic melt before recrystallization, we may conclude that oriented PE chains in ultrathin films possessed a long-term memory of the preparation-induced chain stretching. Considering that the morphology and relaxation kinetics of PE films depended appreciably on the substrate properties and film thickness, we conclude that the formation of asymmetric leaf-shaped crystalline structures was also affected by the interaction of PE chains with the substrate and spatial confinement. The present results may shed new light on slow relaxation and reorganization processes encountered when long-chain polymers became oriented during sample processing.

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“…The atomic force microscope (AFM) is particularly wellsuited to the study of nonconducting samples. 32 There have appeared in the literature many examples of AFM images obtained on oriented polymer films, [33][34][35] single crystals, 36,37 meltcrystallized polymers, 38,39 fibers, 40,41 and liquid crystalline polymers. 42 The ease of sample preparation combined with the ability of AFM to yield structural information on a nanometre scale have made this technique increasingly popular.…”

Section: Introductionmentioning

confidence: 99%

Observations of crystallization and melting in poly(ethylene oxide)/poly(methyl methacrylate) blends by hot-stage atomic-force microscopy

Pearce

Vancso

1998

J. Polym. Sci. B Polym. Phys.

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The binary blend of poly(ethylene oxide)/atactic poly(methyl methacrylate) is examined using hot‐stage atomic‐force microscopy (AFM) in conjunction with differential scanning calorimetry and optical microscopy. It was found possible to follow in real time the melting process, which reveals itself to be nonuniform. This effect is ascribed to the presence of lamellae having different thicknesses. The crystallization process of poly(ethylene oxide) from the miscible melt is also followed in real time by AFM, affording detailed images of the impingement of adjacent spherulites and direct observation of lamellar growth and subsequent polymer solidification in the interlamellar space.© 1998 John Wiley & Sons, Inc. J. Polym. Sci. B Polym. Phys. 36: 2643–2651, 1998

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AFM and SALS Characterization of Spherulitic Structure in Polyethylene

Cited by 6 publications

References 16 publications

Application of AFM on the Adhesion Studies of Oxygen-Plasma-Treated Polypropylene and Lignocellulosics

Application of AFM on the Adhesion Studies of Oxygen-Plasma-Treated Polypropylene and Lignocellulosics

Formation of Asymmetric Leaf-Shaped Crystals in Ultrathin Films of Oriented Polyethylene Molecules Resulting from High-Temperature Relaxation and Recrystallization

Observations of crystallization and melting in poly(ethylene oxide)/poly(methyl methacrylate) blends by hot-stage atomic-force microscopy

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