Crack propagation and defect formation at polymer interfaces investigated by ultra-small angle X-ray scattering

Lorenz-Haas, C.; Müller‐Buschbaum, Peter; Ittner, Thilo; Kraus, Jürgen; Mahltig, Boris; Cunis, S.; Krosigk, G. von; Gehrke, Rainer; Creton, Costantino; Stamm, Manfred

doi:10.1039/b210684a

Cited by 6 publications

(5 citation statements)

References 42 publications

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“…The length scale is not accessible for conventional SAXS. Compared to SAXS, synchrotron ultrasmall-angle X-ray scattering (USAXS) has the advantage of giving access to quite small q-values and provides the possibility to study the large-scale structure evolution during the deformation of polymeric materials [31,51,52].…”

Section: Introductionmentioning

confidence: 99%

Lamellar Thickness and Stretching Temperature Dependency of Cavitation in Semicrystalline Polymers

Wang

Jiang

et al. 2014

PLoS ONE

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Polybutene-1 (PB-1), a typical semicrystalline polymer, in its stable form I shows a peculiar temperature dependent strain-whitening behavior when being stretched at temperatures in between room temperature and melting temperature of the crystallites where the extent of strain-whitening weakens with the increasing of stretching temperature reaching a minima value followed by an increase at higher stretching temperatures. Correspondingly, a stronger strain-hardening phenomenon was observed at higher temperatures. The strain-whitening phenomenon in semicrystalline polymers has its origin of cavitation process during stretching. In this work, the effect of crystalline lamellar thickness and stretching temperature on the cavitation process in PB-1 has been investigated by means of combined synchrotron ultrasmall-angle and wide-angle X-ray scattering techniques. Three modes of cavitation during the stretching process can be identified, namely “no cavitation” for the quenched sample with the thinnest lamellae where only shear yielding occurred, “cavitation with reorientation” for the samples stretched at lower temperatures and samples with thicker lamellae, and “cavitation without reorientation” for samples with thinner lamellae stretched at higher temperatures. The mode “cavitation with reorientation” occurs before yield point where the plate-like cavities start to be generated within the lamellar stacks with normal perpendicular to the stretching direction due to the blocky substructure of the crystalline lamellae and reorient gradually to the stretching direction after strain-hardening. The mode of “cavitation without reorientation” appears after yield point where ellipsoidal shaped cavities are generated in those lamellae stacks with normal parallel to the stretching direction followed by an improvement of their orientation at larger strains. X-ray diffraction results reveal a much improved crystalline orientation for samples with thinner lamellae stretched at higher temperatures. The observed behavior of microscopic structural evolution in PB-1 stretched at different temperatures explains above mentioned changes in macroscopic strain-whitening phenomenon with increasing in stretching temperature and stress-strain curves.

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Section: Introductionmentioning

confidence: 99%

Lamellar Thickness and Stretching Temperature Dependency of Cavitation in Semicrystalline Polymers

Wang

Jiang

et al. 2014

PLoS ONE

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“…X‐ray scattering measurements under in situ or ex situ mechanical loading conditions can help to detect the orientation of domains (small‐angle scattering)75, 76 and also the change of crystallinity and crystallite orientations in semi‐crystalline thermoplastics (wide‐angle scattering) 76–78. The occurrence of voids between filler particles and matrix due to delamination or between two different polymers can be easily detected by small‐angle X‐ray scattering (SAXS) 79, 80. With static and dynamic neutron scattering techniques, namely small‐angle neutron scattering (SANS) and neutron spin echo measurements, chain conformations around nanofillers81 and the segmental dynamics of the polymer under confinements due to an interface82 can be detected, thus helping to understand filler matrix interactions.…”

Section: Commercial Passenger Aircraftmentioning

confidence: 99%

“…Multilayered polymer coatings can be characterised by neutron reflectometry. The latter method also allows for the determination of the inter‐diffusion profiles between different polymer layers 80, 83. If polymer coatings possess a lateral nanostructuring, perpendicular to the substrate, grazing‐incidence SAXS and SANS (GISAXS, GISANS)84 are applicable to simultaneously monitor the perpendicular and the parallel to the surface structuring in films with thicknesses in the range of a few nanometers up to a few hundred nanometers.…”

Section: Commercial Passenger Aircraftmentioning

confidence: 99%

Research with Neutron and Synchrotron Radiation on Aerospace and Automotive Materials and Components

Kaysser¹,

Eßlinger²,

Abetz³

et al. 2011

Adv Eng Mater

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Characterization with neutrons and synchrotron radiation has yielded essential contributions to the research and development of automotive and aerospace materials, processing methods, and components. This review mainly emphasises developments related to commercial passenger airplanes and light‐duty cars. Improved and partly new materials for the reduction of airframe weight and joining by laser‐beam welding and friction stir welding are ongoing areas of assessment. Chemical reactions, microstructure development, and residual stresses are frequently measured. Polymers and polymer matrix composites often require special experimental techniques. The thrust‐to‐weight ratio of aero‐engines is increasing due to the improved design of components and the use of innovative materials. Investigations on superalloys, γ‐TiAl, and thermal barrier coatings are described in some detail. A discussion of the use of neutron and synchrotron diffraction in automotive applications covers the analysis of surface effects with respect to lubricants and wear, as well as the investigation of microstructure development, deformation, and fatigue behavior of materials, welds and components. Special steels, Al and Mg alloys are discussed and residual stresses in automotive components such as gears or crankshafts are described. Applications of characterization methods on membranes for polymeric membrane fuel cells and on nanocrystalline metal hydrides for hydrogen storage are shown. The degradation of railway tracks after long‐term use is taken as an example for the application of synchrotron methods to transport systems beyond the commercial aircraft and light duty passenger car.

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“…Experimental studies on interface−adhesion relationships have been carried out mainly by neutron reflectivity, ,, secondary ion mass spectroscopy (SIMS), , X-ray scattering , and forward recoil spectrometry (FRES) . We previously reported in a communication that high-resolution scanning electron microscopy (HR-SEM) with an in-lens detector system has a potential for providing deeper understanding of interfacial structures and fracture mechanism .…”

Section: Introductionmentioning

confidence: 99%

“…2,4 In the welding of a polymer to itself, a sharp transition from chain pull out (or scission) to crazing takes place when the interfacial thickness exceeds a critical value that is closely related to the entanglement distance. 1 Experimental studies on interface-adhesion relationships have been carried out mainly by neutron reflectivity, 1,2,11 secondary ion mass spectroscopy (SIMS), 12,13 X-ray scattering 14,15 and forward recoil spectrometry (FRES). 16 We previously reported in a communication that high-resolution scanning electron microscopy (HR-SEM) with an in-lens detector system has a potential for providing deeper understanding of interfacial structures and fracture mechanism.…”

Section: Introductionmentioning

confidence: 99%

Interfacial Entanglements between Glassy Polymers Investigated by Nanofractography with High-Resolution Scanning Electron Microscopy

et al. 2008

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Fracture surfaces created during the interfacial failure of weak interfaces between glassy polymers were investigated with high-resolution scanning electron microscopy (HR-SEM). As reported in an earlier communication (Macromol. Rapid Commun.200728915921), we found that interfacial failures between immiscible polymers produced large number of nanosized fibrils on the fracture surfaces. In order to investigate the mechanism of such ultra small structure formation in the crack propagation process, welding experiments of monodispersed polystyrenes with different molecular weights were employed by the asymmetric double cantilever beam (ADCB) test. The “nano-fibrils” were produced during the fractures of the interfaces between polystyrenes with the molecular weight higher than 2000, of which thickness was comparable to the entanglement spacing. It was found that the “nano-fibrous” formation bearing in the crack propagation reflected the local entanglement structures formed at narrow interfaces comparable to the entanglement spacing.

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Crack propagation and defect formation at polymer interfaces investigated by ultra-small angle X-ray scattering

Cited by 6 publications

References 42 publications

Lamellar Thickness and Stretching Temperature Dependency of Cavitation in Semicrystalline Polymers

Lamellar Thickness and Stretching Temperature Dependency of Cavitation in Semicrystalline Polymers

Research with Neutron and Synchrotron Radiation on Aerospace and Automotive Materials and Components

Interfacial Entanglements between Glassy Polymers Investigated by Nanofractography with High-Resolution Scanning Electron Microscopy

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