FTIR Investigation of UHMWPE Oxidation Submitted to Accelerated Aging Procedure

Rocha, Magda Francisca Goncalves; Mansur, Alexandra A.P.; Mansur, Herman S.

doi:10.1002/masy.201051065

Cited by 16 publications

(10 citation statements)

References 16 publications

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“…Studies have shown that polyethylene wear patterns in articial joint replacements are not always identical and cannot be explained exclusively by mechanical factors, such as the weight and degree of physical activity of the patients. [115][116][117] In cases of premature and excessive wear of polyethylene bearings, chemical degradation and oxidation of the polymer can signicantly lower its mechanical resistance and result in an accelerated wear-off process. 118,119 Polymer oxidation, which results in the embrittlement of the prosthetic material, can generate wear debris that eventually triggers an immune response and subsequent implant loosening (Fig.…”

Section: Oncology: Tumor Treatment and Magnetic Hyperthermiamentioning

confidence: 99%

Magnetic particle imaging: advancements and perspectives for real-time in vivo monitoring and image-guided therapy

2013

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Magnetic particle imaging (MPI) is an emerging biomedical imaging technology that allows the direct quantitative mapping of the spatial distribution of superparamagnetic iron oxide nanoparticles. MPI's increased sensitivity and short image acquisition times foster the creation of tomographic images with high temporal and spatial resolution. The contrast and sensitivity of MPI is envisioned to transcend those of other medical imaging modalities presently used, such as magnetic resonance imaging (MRI), X-ray scans, ultrasound, computed tomography (CT), positron emission tomography (PET) and single photon emission computed tomography (SPECT). In this review, we present an overview of the recent advances in the rapidly developing field of MPI. We begin with a basic introduction of the fundamentals of MPI, followed by some highlights over the past decade of the evolution of strategies and approaches used to improve this new imaging technique. We also examine the optimization of iron oxide nanoparticle tracers used for imaging, underscoring the importance of size homogeneity and surface engineering. Finally, we present some future research directions for MPI, emphasizing the novel and exciting opportunities that it offers as an important tool for real-time in vivo monitoring. All these opportunities and capabilities that MPI presents are now seen as potential breakthrough innovations in timely disease diagnosis, implant monitoring, and image-guided therapeutics.

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Section: Oncology: Tumor Treatment and Magnetic Hyperthermiamentioning

confidence: 99%

Magnetic particle imaging: advancements and perspectives for real-time in vivo monitoring and image-guided therapy

2013

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“…It has been shown that subjecting PE to mild oxidative conditions produces oxygen-containing low molecular mass degradation products on the surface of the substrate, mainly mono- and dicarboxylic acids, along with gaseous products, depending on the conditions during the degradation. Oxidation can take place in air or in water and is facilitated by oxidizing chemicals, such as nitric acid and hydrogen peroxide, in combination with an elevated temperature or UV light. − Due to its energetically favorable transition state, succinic acid is often the most abundant product formed during decomposition …”

Section: Introductionmentioning

confidence: 99%

Trash to Treasure: Microwave-Assisted Conversion of Polyethylene to Functional Chemicals

Bäckström

Odelius

Hakkarainen

2017

Ind. Eng. Chem. Res.

118

106

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An effective microwave-assisted process for recycling low-density polyethylene (LDPE) waste into value-added chemicals was developed. To achieve fast and effective oxidative degradation aimed at production of dicarboxylic acids, nitric acid was utilized as an oxidizing agent. Different conditions were evaluated, where recycling time and concentration of oxidizing agent were varied and the end products were characterized by FTIR, NMR, and HPLC. After just 1 h of microwave irradiation at 180 °C in relatively dilute nitric acid solution (0.1 g/mL), LDPE powder was totally degraded. This transformation led to few well-defined water-soluble products, mainly succinic, glutaric, and adipic acids, as well as smaller amounts of longer dicarboxylic acids, acetic acid, and propionic acid. The length of the obtained dicarboxylic acids could to some extent be tuned by adjusting the reaction time, temperature, and amount of oxidizing agent. Finally, the developed process was verified by recycling LDPE freezer bags as model LDPE waste. The freezer bags were converted mainly into dicarboxylic acids with a yield of 71%, and the carbon efficiency of the process was 37%. The developed method can, thus, contribute to a circular economy and offers new possibilities to increase the value of plastic waste.

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“…This oxidation reaction is "automatic", known as "automatic oxidation". 19,20 It is generally relatively slow and can be promoted by many factors such as heat. Heat can force oxygen to penetrate into the interior from the exterior of the polymer.…”

Section: Surface Topographymentioning

confidence: 99%

Effects of thermal‐oxidative aging processes on tribological properties of polyformaldehyde and ultra‐high molecular weight polyethylene: A comparative study

Chen

Wei

Cheng

et al. 2021

J of Applied Polymer Sci

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Using thermal-oxidative aging and tribological experiments, effects of thermaloxidative aging processes on tribological properties of polyformaldehyde (POM) and ultra-high molecular weight polyethylene (UHMWPE) were evaluated and compared with each other. It was found that the color of UHMWPE surface after aging has turned to yellow, while that of POM surface has no obvious change. The aging factors lead to dimensional change of UHMWPE disk specimens from the original circle to the ellipse in the meantime. Tribological experiments show that friction coefficients of the pairs of POM/GCr15 and UHMWPE/GCr15 tend to decrease after thermal-oxidative aging, and the decreasing tendency in friction coefficients of POM/GCr15 is more distinct.The results of this study will contribute to the understanding of the relationship between aging and tribological properties of POM and UHMWPE, and enrich the theory of polymer tribology.

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FTIR Investigation of UHMWPE Oxidation Submitted to Accelerated Aging Procedure

Cited by 16 publications

References 16 publications

Magnetic particle imaging: advancements and perspectives for real-time in vivo monitoring and image-guided therapy

Magnetic particle imaging: advancements and perspectives for real-time in vivo monitoring and image-guided therapy

Trash to Treasure: Microwave-Assisted Conversion of Polyethylene to Functional Chemicals

Effects of thermal‐oxidative aging processes on tribological properties of polyformaldehyde and ultra‐high molecular weight polyethylene: A comparative study

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