Ultra‐Small‐Angle X‐Ray Scattering Study of PET/PC Nanolayers and Comparison to AFM Results

Ania, F.; Puente‐Orench, Inés; Calleja, F. J. Baltá; Khariwala, D.; Hiltner, A.; Baer, E.; Roth, Stephan V.

doi:10.1002/macp.200700639

Cited by 11 publications

(14 citation statements)

References 23 publications

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“…In a preceding paper [8], comparison of ultra-small-angle X-ray scattering (USAXS) and atomic force microscopy (AFM) results shed light on many details of the highly regular nanolayered structure present in coextruded poly(ethylene terephthalate)/polycarbonate (PET/PC) films. The experimental long spacings for these semicrystalline/amorphous nanolayers, derived from USAXS, showed values which correlate fairly well with the nominal periodicity values of the stacks prepared by the coextrusion method.…”

Section: Introductionmentioning

confidence: 99%

Study of the multilayered nanostructure and thermal stability of PMMA/PS amorphous films

Ania

Calleja

Henning

et al. 2010

Polymer

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a b s t r a c tThe nanolayered structure of a forced-assembly of two immiscible amorphous polymers, prepared by layer-multiplying coextrusion, is analyzed for the first time by means of USAXS. The experimental long spacings for the series of PMMA/PS films studied show a good correlation with the nominal periodicity values of the stacks. In addition, the long spacings, derived from a localized area in AFM, are also in good agreement with the USAXS values averaged over much larger areas. The structural variation, after thermal treatment, of two samples with nominal periodicities of 174 and 215 nm is reported. In the range RT-140 C, the nanolayered structure is mostly well preserved as evidenced by AFM. However, the absence of USAXS maxima after annealing at temperatures included in the above range has been tentatively explained by interfacial coarsening and spinodal dewetting occurring between the forcedassembled polymer layers. Above 140 C, the interfacially driven break-up of the layers ends up with the final disappearance of the multilayered structure.

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Section: Introductionmentioning

confidence: 99%

Study of the multilayered nanostructure and thermal stability of PMMA/PS amorphous films

Ania

Calleja

Henning

et al. 2010

Polymer

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“…Although the difference in electron density between iPP and PA6 is not very large, other similar systems do show the presence of several scattering maxima [4,5]. It is then concluded that, in this case, the absence of USAXS peaks should be related to the irregular layered structure evidenced in the TEM micrographs (Fig.…”

Section: Usaxs Resultsmentioning

confidence: 76%

“…The thermal stability of the laminated architecture of the films was also tested at temperatures even higher than the glass transition temperature of both constituent polymers. For the PET/PC system, the multilayers are well preserved after heat treatments up to T a 150°C, showing only a large increment of the USAXS scattering power due to the higher electron density difference among alternating layers provoked by the crystallization of PET [4]. The PMMA/PS system in turn, shows the absence of USAXS maxima after heat treatments at an intermediate range of temperatures (110-130ºC); while AFM evidences that the nanolayered structure is mostly preserved.…”

Section: Introductionmentioning

confidence: 96%

“…In preceding papers [4,5], the study of the forced assembly of co-extruded pairs of immiscible polymers using ultra-small-angle x-ray scattering (USAXS) shed light on several details of their highly regular nanolayered structure. The experimental long spacings found in multilayered films of a semicrystalline/amorphous system such as poly(ethylene terephthalate)/polycarbonate (PET/PC) and those for an amorphous/amorphous system such as poly(methyl methacrylate)/poly(styrene) (PMMA/PS) showed values which correlate well with the nominal periodicities of the stacks and with the layer periodicities derived, on a more local scale, from atomic force microscopy (AFM) images.…”

Section: Introductionmentioning

confidence: 99%

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Nanostructure and crystallization phenomena in multilayered films of alternating iPP and PA6 semicrystalline polymers

Ania

Calleja

Flores

et al. 2012

European Polymer Journal

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The present work is concerned with the study of the crystalline morphology and the nanostructure of a multilayered system of two alternating immiscible semicrystalline polymers: isotactic polypropylene (iPP) and polyamide 6 (PA6). Films with a volume ratio of 70/30 were prepared by means of layer multiplying coextrusion. Contrary to previous experiments, performed with semicrystalline/amorphous and amorphous/amorphous nanolayered systems, the studied iPP/PA6 film does not exhibit a well defined maximum in the USAXS patterns.This result accounts for an irregular layered structure, as further confirmed by means of TEM images. Nevertheless, such a layered assembly still influences the crystallization behaviour of both constituent polymers. On the one hand, the crystallization of PA6 within the multilayered material is substantially hindered as evidenced by its weak scattering intensity. Real time studies as a function of temperature undoubtedly detect the presence of a WAXS peak and a SAXS maximum associated to PA6 above the melting temperature of iPP. Room temperature AFM studies also confirm the occurrence of crystalline structures within the PA6 layers. On the other hand, SAXS and WAXS measurements at room temperature reveal the occurrence of an oriented lamellar morphology within the iPP layers bearing uniaxial symmetry around an axis perpendicular to the layers surface. Results show that the crystalline molecular chains are placed mainly parallel to the layer surfaces forming edge-on lamellae. Moreover, X-ray scattering results are in agreement with the occurrence of two populations of lamellae, both edge-on and perpendicular to each other, in agreement with the crosshatched morphology observed by AFM.

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“…The mechanism of coextrusion is that two polymer components are stacked and fed into multiplying system and finally form a layered membrane. With the development of the coextrusion techniques, polymer membranes have been developed with layers in nano scale, which have a truly biomimetic nature [9,10]. The unique microstructures allow the membranes many potential applications.…”

Section: Introductionmentioning

confidence: 99%

Mechanical Property Studies of Nanolayered Polymer Membranes

Shen

Abdel-Mohti

2016

Proceedings of 2nd International Electronic Conference on Materials

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Nanolayered polymer membranes, which have biomimicking layered structures, have been developed in recent years. The unique microstructures allow the membranes to have many potential applications. To facilitate the application of the membranes, the understandings of mechanical properties of the pristine and aged membranes are needed for the short and long-term applications. The current study focuses on the study of the relationship between the microstructure of the membrane and the mechanical properties including stiffness, strength, and ductility. The effect of the microstructure on the long-term application has been evaluated by thermal aging. The nanolayered polymer membranes have been subjected to thermal aging at various temperatures for different time frames. It has been found that the microstructure parameters, such as layer thickness, have great effect on the mechanical properties and thermal aging resistance. The thinner the layer of the membrane is, the better the strength and thermal aging resistance are.

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Ultra‐Small‐Angle X‐Ray Scattering Study of PET/PC Nanolayers and Comparison to AFM Results

Cited by 11 publications

References 23 publications

Study of the multilayered nanostructure and thermal stability of PMMA/PS amorphous films

Study of the multilayered nanostructure and thermal stability of PMMA/PS amorphous films

Nanostructure and crystallization phenomena in multilayered films of alternating iPP and PA6 semicrystalline polymers

Mechanical Property Studies of Nanolayered Polymer Membranes

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