Morphological characterisation of the crystalline structure of cold-drawn HDPE used as a model material for the environmental stress cracking (ESC) phenomenon

Lagaron, J. M.; Dixon, N. Michael; Reed, Warren; Pastor, J. M.; Kip, Bert J.

doi:10.1016/s0032-3861(98)00500-x

Cited by 73 publications

(81 citation statements)

References 37 publications

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“…They recommended using the I 1416 /I 1295 intensity ratio, after Strobl and Hagedorn, [37] to follow the changes in the concentration of the orthorhombic modification, since the 1295 cm −1 band is independent of the chain conformation. Also, Lagaron et al [36] have observed that the presence of monoclinic or triclinic structures would influence the factor-group splitting of the orthorhombic bands (1416 and 1440 cm −1 due to the presence of two PE chains per unit cell), and have further demonstrated that the reduction/absence of orthorhombic crystallinity results in the elimination of the 1415 cm −1 factor-group split band. These authors have observed the presence of a monoclinic phase in cold-drawn high-density polyethylene; they have explained the spectral changes not only by the presence of the monoclinic phase but also by the creation of an ill-defined orthorhombic crystalline structure containing dislocations, disrupted crystals, phase-transformed crystals and some chain unfolding.…”

Section: Resultsmentioning

confidence: 97%

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Raman characterisation of conventional and cross‐linked polyethylene in acetabular cups run on a hip joint simulator

Taddei

Foggia

Affatato

2011

J Raman Spectroscopy

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Five sets of differently sterilised conventional ultra-high molecular weight polyethylene (UHMWPE) and cross-linked polyethylene (XLPE) acetabular cups were run for 5 million cycles on a hip joint simulator in order to evaluate their wear behaviour in relation to material properties (PE grade, conventional or cross-linked) and sterilisation method (ethylene oxide (EtO) treatment or γ -irradiation). Gravimetric measurements revealed that conventional UHMWPE wore significantly more than XLPE. The differences in wear behaviour could be partly related to the orthorhombic contents obtained by Raman spectroscopy in the unworn areas of the cups: XLPE cups showed a significantly higher crystallinity degree than the UHMWPE specimens. Raman analysis showed that wear testing did not significantly modify the orthorhombic content of any of the tested acetabular cups. However, the set of cups that showed the highest weight loss, i.e. γ -sterilised PE GUR1020, appeared the most homogeneously polished upon wear testing; from a molecular point of view, only this set of cups showed a significant increase of the I 1130 /I 1060 intensity ratio, suggesting the occurrence of chain orientation. On the other hand, XLPE cups, despite the lowest weight loss undergone, showed a decrease in the amorphous content upon wear testing as well as a limited orthorhombic → monoclinic transformation, which did not appear detrimental.

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Section: Resultsmentioning

confidence: 97%

“…[26,27] The I 1130 /I 1060 band intensity ratio has been used to evaluate the occurrence of orientation [36,38,39] upon wear testing. Figure 1 shows the mean weight loss obtained after 5 million cycles on the different sets of cups.…”

Section: Micro-raman Crystallinity Measurements On the Acetabular Cupsmentioning

confidence: 99%

Raman characterisation of conventional and cross‐linked polyethylene in acetabular cups run on a hip joint simulator

Taddei

Foggia

Affatato

2011

J Raman Spectroscopy

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“…These factors make the structure of the exposed sample highly strained. Effects of mechanical strain on the intensity reduction of Raman scattering for all the peaks in high-density polyethylene (HDPE) has already been reported 21 . The decrease in intensity has been attributed to the imposed strain in C-C bonds.…”

Section: Resultsmentioning

confidence: 96%

Photo-induced Structural Changes in Polyolefin-nanoclay Composite

Chauhan¹,

Singh²,

Shrivastava³

et al. 2008

DSJ

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The morphology of films prepared by melt-blending polyethylene (PE) and polypropylene (PP) with and without nanoclay was investigated after exposure to outdoor solar radiations for 45 days utilising many techniques. The Raman spectra revealed decreased intensity for all the characteristic Raman bands for PP and PE. The Fourier transform infrared spectroscopy showed formation of hydroxyl/hydroperoxy and carbonyl groups in the exposed samples. The weathered films after 45 days of solar exposure became brittle as indicated by loss in physical properties and the stress-strain curves. The clay-containing films showed higher strength loss after solar exposure. The fractured ends of the exposed films showed flat, smooth, and sharp surfaces, indicative of brittle fracture, compared to the unexposed sample.

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“…35,36 The model by Strobl and Hagedorn 35 represents a simplification; actually, some authors have questioned the evidence for the existence of a third phase in PE on the basis of Raman spectroscopic data. 37 In addition, on the basis of the Raman spectra of semi-crystalline …”

Section: Methodsmentioning

confidence: 99%

“…The fraction of all-trans sequences was evaluated through the following ratio, according to a method proposed by Lagaron et al 36 :…”

Section: Methodsmentioning

confidence: 99%

May the surface roughness of the retrieved femoral head influence the wear behavior of the polyethylene liner?

et al. 2015

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This study was aimed at determining the surface degradation occurred on retrieved ceramic and metallic heads, as well as the influence of the head surface quality on the wear of the polyethylene counterface. To this purpose, 14 ceramic and 14 metallic femoral heads retrieved at revision surgery were examined. Scanning electron microscopic analysis provided visual evidence that some metallic heads presented crescent wear more often than the ceramic ones; the former showed a higher volumetric loss (as determined by Coordinate Measuring Machine) than the latter, but less negative Rsk values. This apparent lack of correlation between volumetric loss (i.e., wear factor) and roughness data may be explained by considering that they are two temporally variant parameters. No significant differences were observed between the Ra values of the two sets of femoral heads. The cups articulating against metal heads were characterized by higher mean wear volumes than those articulating against alumina although this difference was not statistically significant; metal heads displayed significantly higher mean wear volumes than alumina heads. The micro-Raman analysis of the cup articulated against the most worn alumina femoral head showed an orthorhombic into monoclinic phase transformation that was not observed in the cups coupled to metal heads. The obtained results showed that the surface finishing of the femoral head (in terms of Rsk values) determined the morphological changes experienced by the ultra-high-molecular-weight polyethylene crystalline phase at the molecular level. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1374-1385, 2016.

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Morphological characterisation of the crystalline structure of cold-drawn HDPE used as a model material for the environmental stress cracking (ESC) phenomenon

Cited by 73 publications

References 37 publications

Raman characterisation of conventional and cross‐linked polyethylene in acetabular cups run on a hip joint simulator

Raman characterisation of conventional and cross‐linked polyethylene in acetabular cups run on a hip joint simulator

Photo-induced Structural Changes in Polyolefin-nanoclay Composite

May the surface roughness of the retrieved femoral head influence the wear behavior of the polyethylene liner?

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