Morphological Raman analysis of short chain branched ethylene and propylene metallocenic copolymers

Satti, Angel José; Quijada, Raúl; Pastor, J. M.; Vallés, Enrique M.

doi:10.1016/j.polymertesting.2018.03.036

Cited by 3 publications

(5 citation statements)

References 63 publications

(187 reference statements)

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“…According to Satti et al, the B‐UHMWPE/Vitamin C results obtained by DSC are practically the same (Table ); not observing differences in crystallinity values of samples using DSC. However, the B‐UHMWPE/Vitamin C results herein obtained by Raman were different from each other and are in agreement with those obtained by Satti et al These differences in the results obtained between both techniques have been attributed by some authors to experimental conditions, where sample evaluation using Raman occurred at room temperature, while samples in DSC analyses are first melted, then cooled, and melted again to be evaluated. The B‐UHMWPE crystallinity value obtained by DSC was slightly higher than that obtained using Raman technique.…”

Section: Resultssupporting

confidence: 81%

“…Comparing the AFM for B‐UHMWPE film (Figure a) with that of the 2.0% wt Vitamin C compound (Figure c), it is noted that the Raman analysis method was more sensitive for identifying differences in the microstructure of B‐UHMWPE with Vitamin C added. Other authors also observed differing crystallinity values as obtained by Raman and DSC . For example, Satti et al observed different crystallinity values in polyolefins modified with certain co‐monomers as obtained by DSC and Raman techniques.…”

Section: Resultsmentioning

confidence: 97%

“…Other authors also observed differing crystallinity values as obtained by Raman and DSC . For example, Satti et al observed different crystallinity values in polyolefins modified with certain co‐monomers as obtained by DSC and Raman techniques. According to Satti et al, the B‐UHMWPE/Vitamin C results obtained by DSC are practically the same (Table ); not observing differences in crystallinity values of samples using DSC.…”

Section: Resultsmentioning

confidence: 97%

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Antioxidant Effects of Vitamin C on Biomedical UHMWPE Compounds

Souza¹,

Fim²,

Lima³

et al. 2019

Macromolecular Symposia

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The aim of the present study is to evaluate the antioxidant activity of ascorbic acid (Vitamin C) at concentrations of 0.5, 1.0, and 2.0% wt on Biomedical Ultra High Molecular Weight Polyethylene (B‐UHMWPE), using a stable free radical 2,2‐diphenyl‐1‐picryl‐hydrazyl (DPPH). The compounds are prepared by compression molding at 160 °C for 6 min, and pressure of 10 MPa. Infrared spectroscopy indicated a weak interaction between the compound constituents, at 3600, 1800, and 1500 cm−1 bands attributed to Vitamin C. Atomic force microscopy (AFM) revealed that the addition of 2.0% wt. of Vitamin C promoted B‐UHMWPE crystalline particle size decreases and molecular disorder. In the presence of the vitamin, Raman spectroscopy suggested a decrease in the degree of polymer crystallinity which may be attributable to modifications in morphological aspects of the polymer. Vitamin C acted as an antioxidant agent, an important result; an increasing amount of radical is scavenged with the addition of the vitamin to the compounds. Thus, Vitamin C presents potential as an antioxidant for B‐UHMWPE compounds.

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Section: Resultssupporting

confidence: 81%

Section: Resultsmentioning

confidence: 97%

Section: Resultsmentioning

confidence: 97%

See 1 more Smart Citation

Antioxidant Effects of Vitamin C on Biomedical UHMWPE Compounds

Souza¹,

Fim²,

Lima³

et al. 2019

Macromolecular Symposia

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“…808 cm −1 is associated with helical chains within crystals (r[CH3] and backbone stretching ν[CC]), with 840 cm −1 assigned to shorter chains in helical conformation 43,46 . The increase in the intensity ratio I840/I808 has been considered in relation to helical chain disruption/isomeric defects 47,48 . A loss of CC coupling results in greater emission from side‐group mode r(CH3), expressed as a shift of the Raman band from 808 to 840 cm −1 43 .…”

Section: Resultsmentioning

confidence: 99%

“… 43 , 46 The increase in the intensity ratio I840/I808 has been considered in relation to helical chain disruption/isomeric defects. 47 , 48 A loss of C—C coupling results in greater emission from side‐group mode r(CH3), expressed as a shift of the Raman band from 808 to 840 cm −1 . 43 When comparing the intensity ratios of I840/I808, it is clear that the LT Ti‐PP mesh expresses greater helical chain defects compared to both the ST Ti‐PP mesh and the pristine PP mesh.…”

Section: Resultsmentioning

confidence: 99%

Characterization in respect to degradation of titanium‐coated polypropylene surgical mesh explanted from humans

2023

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Titanium-coated polypropylene (Ti-PP) mesh was introduced in 2002 as a surgical mesh for the treatment of hernias and shortly after for pelvic floor surgery, with the aim of improving biocompatibility when compared to non-titanised/regular PP mesh implants. The application of a titanium coating could also be beneficial to address concerns regarding the exposure of PP in an in vivo environment. Many studies have shown that PP, although it is widely accepted as a stable polymer, is subject to oxidation and degradation, such degradation affects the mechanical behavior, that is, the stiffness and tensile strength of PP mesh. Despite the wide clinical use of Ti-PP surgical meshes, no study has yet investigated the residual material properties post clinical deployment and subsequent explantation. In this study, two explanted Ti-PP mesh samples each having different incorporation durations from two patients were examined. Material analysis conducted within this study includes the following techniques: attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), Raman spectroscopy, low voltagescanning electron microscopy (LV-SEM), backscattered electron (BSE) imaging, energy dispersive X-ray spectroscopy (EDS) and secondary election hyperspectral imaging (SEHI). The hypothesis of this study is that the Ti coating successfully shields the PP mesh from oxidative stress in vivo and thus protects it from degradation. The results of this analysis show for the first time evidence of bulk oxidation, surface degradation, and environmental stress cracking on explanted Ti-PP meshes.

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