Dynamic mechanical analysis of Norsorex/acrylonitrile butadiene rubber blends and their application in vibration control of steel frames

Yang

Proceedings of the Institution of Mechanical Engineers, Part L:

et al. 2023

Vibration analysis and control are the main issues of heavy buoyancy regulators, which can improve the runtime performance and reduce the power loss. It is an effective approach to add rubber-based isolators to control the vibrations of the heavy buoyancy regulator. However, the vibration reduction effect of the rubber-based isolators is closely related to their structures and material performance. In this study, according to the geometrics of the connecting components, the structures of the rubber-based isolators are designed by using the vibration theory. The rubber-based isolators with different structures and hardness are considered in the finite element models, whose results are used to achieve the optimal design cases. The vibration isolation transmissibility and static deformation ratio of the rubber-based isolator are discussed. The frequency–displacement characteristics of the heavy buoyancy regulator are also analyzed. The results show that the two presented rubber-based isolators can be used to control the vibrations of the heavy buoyancy regulator. It seems that the presented method can be used for the vibration analysis and control of the heavy buoyancy regulators in underwater vehicles.

Section: Introductionmentioning

confidence: 99%

A vibration analysis and control method of a heavy buoyancy regulator in an underwater vehicle

Yang

Proceedings of the Institution of Mechanical Engineers, Part L:

et al. 2023

“…Dynamic mechanical analysis (DMA) showed that the temperature range of effective damping (tanδ ≥ 0.3) of vulcanized PNR was about 113 • C, and this range decreases as the EPDM content in the mixture increases. The PNR/EPDM vulcanizate at a ratio of 25/75 phr has a tanδ value at the point of maximum (tanδ max = 1.62) at a temperature of −34 • C. The work [37] describes the damping properties of rubber based on nitrile-butadiene rubber (NBR) and PNB (Norsorex ® ). The DMA results showed that Norsorex at 30 phr in 70 phr NBR significantly improved the damping characteristics of the vulcanizate based on them.…”

Section: Introductionmentioning

confidence: 99%

Effect of Polynorbornene on Physico-Mechanical, Dynamic, and Dielectric Properties of Vulcanizates Based on Isoprene, α-Methylstyrene-Butadiene, and Nitrile-Butadiene Rubbers for Rail Fasteners Pads

Egorov,

Salomatina,

Vassilyev

et al. 2023

J. Compos. Sci.

The article studies the effect of polynorbornene (PNB) in the composition of PNB with Norman 747 LV plasticizer (RC) on the curing characteristics of the rubber compound and the physico-mechanical, dynamic, dielectric properties and the thermal behavior of vulcanizates based on a combination of isoprene, α-methylstyrene-butadiene, and nitrile-butadiene rubbers. It is shown that vulcanizates containing PNB in the composition of the RC had lower conditional tensile strength, hardness, and tear resistance compared to the vulcanizate of the base version of the rubber compound. Studies of dynamic mechanical analysis indicate that an increase in the content of RC, and hence PNB, in the rubber compound contributes to an increase in the mechanical loss factor (tanδ) and a decrease in the storage modulus of vulcanizates. It was found that vulcanized rubber, containing 24.0 parts per hundred of rubber (phr) (8.98 wt. %) PNB as part of the RC, is characterized by stable physico-mechanical, improved vibration-absorbing properties, as well as increased dielectric parameters. This rubber compound can be used as a base for rail fasteners for railroad tracks.

“…Polymers derived from ring-opening metathesis polymerization (ROMP) are industrially important elastomers (e.g., Norsorex) and thermosets. − A challenge with thermoset polymers is their poor solubility and processability, in part due to their cross-linked networks − exactly the characteristics that present challenges for traditional molecular weight characterization methods but that we envisioned would be well-suited to FLIM methods.…”

mentioning

confidence: 99%

Polymer Molecular Weight Determination via Fluorescence Lifetime

García

Blum

2022

J. Am. Chem. Soc.

Control of polymer molecular weight is critical for tailoring structure–function properties; however, traditional molecular weight characterization techniques have limited ability to determine the molecular weight of polymers in real time without sample removal from the reaction mixture, with spatial resolution, and of insoluble polymers. In this work, a fluorescence lifetime imaging microscopy (FLIM) method was developed that overcomes these limitations. The method is demonstrated with polynorbornene and polydicyclopentadiene, polymers derived from ruthenium-catalyzed ring-opening metathesis polymerization (ROMP). The polymer M w, ranging from 35 to 570 kg/mol as determined by gel-permeation chromatography, was quantitatively correlated with the fluorescence lifetime. The revealed correlation then enabled time-resolved measurement of M w during an ongoing ROMP reaction, requiring only 1 s per measurement (of a 45 μm × 45 μm polymer sample area), and provided spatial resolution, resulting in simultaneous characterization of polymer morphology. To provide the fluorescence signal, the initial reaction solutions contained a very low doping of a reactive norbornene monomer labeled with fluorescent boron dipyrromethene (BODIPY), such that 1 in every 107 monomers contained a fluorophore. The resulting FLIM visualization method enables the rapid determination of the molecular weights of growing polymers without removal from the reaction mixture and regardless of polymer solubility.