A Molecular Dynamics Simulation Study on the Relationship between Hydrogen Bond and Damping Properties of AO-70/NBR Composites

2017 ◽  
Vol 748 ◽  
pp. 29-34 ◽  
Author(s):  
Jing Zhu ◽  
Xiu Ying Zhao ◽  
Meng Song ◽  
Yue Han ◽  
Li Liu ◽  
...  
Keyword(s):  
Md Simulation ◽  
Type A ◽  
Dynamics Simulation ◽  
Butadiene Rubber ◽  
Damping Properties ◽  
Type B ◽  
Fractional Free Volume ◽  
Type C ◽  
Hindered Phenol ◽  
The Relationship

This work was try to study the number and types of hydrogen bonds (H-bonds) formed in hindered phenol AO-70/nitrile butadiene rubber (NBR) composites and their contributions to the damping properties by molecular dynamic (MD) simulation and experimental methods. MD simulation results showed that there were four types of H-bonds, namely, type A (AO-70) –OH...NC– (NBR) H-bonds in AO-70/NBR composites, type B (AO-70) –OH...O=C– (AO-70) H-bonds, type C (AO-70) –OH...OH–(AO-70) and D (AO-70) –OH...O–C– (AO-70) H-bonds, what's more, type A and type B H-Bonds formed more easily than others. Fourier transform infrared spectroscopy (FTIR) confirmed the existence of H-bonds. Meanwhile, the AO-70/NBR composites with AO-70 content of 109 phr had the largest number of H-bonds, smallest fractional free volume (FFV) and resulting in the optimistic damping performance of the composites.

Study on the Relationship between the Hydrogen Bond and Damping Properties of Nitrile-Butadiene Rubber/Hindered Phenol Composites by Molecular Dynamics Simulation

2011 ◽  
Vol 410 ◽  
pp. 313-316 ◽  
Author(s):  
Tao Hu ◽  
Qiao Bo ◽  
Xiu Ying Zhao ◽  
Si Zhu Wu
Keyword(s):  
Hydrogen Bonds ◽  
Point Of View ◽  
Polymer Chains ◽  
Dynamics Simulation ◽  
Butadiene Rubber ◽  
Damping Properties ◽  
Fractional Free Volume ◽  
Nitrile Butadiene Rubber ◽  
Hindered Phenol ◽  
The Relationship

This work was try to study the relationship between the damping properties and the hydrogen bonds, fractional free volumes of nitrile-butadiene rubber (NBR)/hindered phenol (AO-80) composites from the microstructural point of view by combining the experimental and molecular simulation studies. The results indicated that the hydrogen bonds (HBs) were formed between AO-80 small molecules and NBR polymer chains. According to simulation results, because of the formed strongest HBs, highest binding energy and the smallest fractional free volume in the NBR/AO-80 composites with the blending ratio of 100/68, it contributed the maximum loss factor and highest modulus. It concluded that there was a suitable proportion of rubber blended with small hindered phenol molecules in the design of damping materials.

Molecular-level insight of hindered phenol AO-70/nitrile-butadiene rubber damping composites through a combination of a molecular dynamics simulation and experimental method

RSC Advances ◽  
2016 ◽  
Vol 6 (89) ◽  
pp. 85994-86005 ◽  
Author(s):  
Xiuying Zhao ◽  
Geng Zhang ◽  
Feng Lu ◽  
Liqun Zhang ◽  
Sizhu Wu
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Experimental Method ◽  
Molecular Level ◽  
Dynamics Simulation ◽  
Butadiene Rubber ◽  
Damping Properties ◽  
Nitrile Butadiene Rubber ◽  
Hindered Phenol

The damping properties of AO-70/NBR composites get a noteworthy increase with the introduction of AO-70—max tan δincreased by 66.9%.

Molecular insights into hydrogen bonds in polyurethane/hindered phenol hybrids: evolution and relationship with damping properties

2014 ◽  
Vol 2 (22) ◽  
pp. 8545-8556 ◽  
Author(s):  
Kangming Xu ◽  
Fengshun Zhang ◽  
Xianlong Zhang ◽  
Qiaoman Hu ◽  
Hong Wu ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Md Simulation ◽  
Damping Properties ◽  
Property Variation ◽  
Damping Property ◽  
Hindered Phenol ◽  
The Relationship

By combining experiments and MD simulation, the relationship between hydrogen bond evolution and damping property variation of TPU was revealed.

scholarly journals The Relationship Between Different Types of Caries and Periodontal Disease Severity in Middle-Aged and Elderly People: Findings from the 4th National Oral Health Survey of China

2020 ◽  
Author(s):  
Lixia Yu ◽  
Xing WANG ◽  
Xi Ping FENG ◽  
Bao Jun TAI ◽  
De Yu HU ◽  
...  
Keyword(s):  
Periodontal Disease ◽  
Elderly People ◽  
Disease Severity ◽  
Type A ◽  
Type B ◽  
Middle Aged ◽  
Aged People ◽  
Different Types ◽  
Type C ◽  
The Relationship

Abstract Background: To explore the relationship between different types of caries and periodontal disease severity in middle-aged and elderly people in China. Methods: The study population consisted of 4,387 middle-aged and 3,225 elderly subjects. Caries was divided into three types: type A, crown caries; type B, lesions involving both the crown and root, which represents mixed type; and type C, root caries. These three types together represent the overall caries situation, which we call type ABC. Caries was quantitated by decayed and filled teeth (DFT index). Periodontitis was evaluated by clinical attachment loss.Results: Middle-aged people with periodontitis had a significant association with DFT of type ABC (OR: 1.09, 95% CI: 1.06‐1.11), type A (OR: 1.05, 95% CI: 1.02‐1.08), type B (OR: 1.20, 95% CI: 1.16-1.28) and type C (OR: 1.36, 95% CI: 1.15-1.60). Elderly people with periodontitis had a significant association with DFT of type ABC (OR: 1.05, 95% CI: 1.03-1.07), type B (OR: 1.07, 95% CI: 1.05-1.10) and type C (OR: 1.30, 95% CI: 1.19-1.42)，but not with type A.Conclusions: Different types of caries in middle-aged people, the overall caries and caries types involving the root surface in elderly people were significantly associated with periodontal disease severity.

Molecular insights into the damping mechanism of poly(vinyl acetate)/hindered phenol hybrids by a combination of experiment and molecular dynamics simulation

RSC Advances ◽  
2015 ◽  
Vol 5 (6) ◽  
pp. 4200-4209 ◽  
Author(s):  
Kangming Xu ◽  
Fengshun Zhang ◽  
Xianlong Zhang ◽  
Jiwei Guo ◽  
Hong Wu ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Hydrogen Bond ◽  
Molecular Dynamics Simulation ◽  
Vinyl Acetate ◽  
Md Simulation ◽  
Dynamics Simulation ◽  
Property Variation ◽  
Damping Property ◽  
Hindered Phenol ◽  
The Relationship

By combining experiment and MD simulation, the relationship between hydrogen bond evolution and damping property variation of PVAc was revealed.

Effects of chain polarity of hindered phenol on the damping properties of polymer-based hybrid materials: insights into the molecular mechanism

2020 ◽  
Vol 40 (5) ◽  
pp. 394-402
Author(s):  
Qiaoman Hu ◽  
Junhui Wang ◽  
Kangming Xu ◽  
Hongdi Zhou ◽  
Yue Huang ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Mechanical Analysis ◽  
Dynamics Simulation ◽  
Damping Properties ◽  
Structure Variation ◽  
Hydrogen Bonding Interactions ◽  
Ft Ir ◽  
Hindered Phenol ◽  
Damping Materials ◽  
The Relationship

AbstractFor hindered phenol (HP)/polymer-based hybrid damping materials, the damping properties are greatly affected by the structure variation of HPs. However, the unclear relationship between them limits the exploitation of such promising materials. Therefore, three HPs with different chain polarity were synthesized to explore the relationship in this paper. The structures of the HPs were firstly confirmed by Nuclear Magnetic Resonance Spectrum, Fourier Transform Infrared Spectroscopy (FT-IR) and X-ray Diffraction (XRD). For further prepared HP/polyurethane hybrids, FT-IR and XRD were also adopted to confirm the hydrogen bonding interactions and micromorphologies. And, Molecular dynamics simulation was further used to characterize the effects of polarity variation on the hydrogen bonding interactions and chain packing of the hybrids in a quantitative manner. Then, combined with dynamic mechanical analysis, the relationship between the chain polarity variation of the hindered phenols and the damping properties was established.

scholarly journals The relationship between different types of caries and periodontal disease severity in middle-aged and elderly people: findings from the 4th National Oral Health Survey of China

2021 ◽  
Author(s):  
Lixia Yu ◽  
Xing WANG ◽  
Xi Ping FENG ◽  
Bao Jun TAI ◽  
De Yu HU ◽  
...  
Keyword(s):  
Periodontal Disease ◽  
Elderly People ◽  
Disease Severity ◽  
Type A ◽  
Type B ◽  
Middle Aged ◽  
Aged People ◽  
Different Types ◽  
Type C ◽  
The Relationship

Abstract Background: The relationship between dental caries and periodontal disease is still controversial. The objective of this study is to explore the relationship between different types of caries and periodontal disease severity in middle-aged and elderly people in China.Methods: The study population consisted of 4,387 middle-aged and 3,225 elderly subjects. Caries were divided into the following three types: type A, crown caries; type B, lesions involving both the crown and root, representing a mixed type; and type C, root caries. These three types together represent the overall caries situation, which we call type ABC. Caries were quantitated by decayed and filled teeth (DFT index). Periodontitis was evaluated by clinical attachment loss.Results: Middle-aged people with periodontitis had a significant association with DFT of type ABC (OR: 1.09, 95% CI: 1.06‐1.11), type A (OR: 1.05, 95% CI: 1.02‐1.08), type B (OR: 1.20, 95% CI: 1.16-1.28) and type C (OR: 1.36, 95% CI: 1.15-1.60). Elderly people with periodontitis had a significant association with DFT of type ABC (OR: 1.05, 95% CI: 1.03-1.07), type B (OR: 1.07, 95% CI: 1.05-1.10) and type C (OR: 1.30, 95% CI: 1.19-1.42) but not type A.Conclusions: Different types of caries in middle-aged people and overall caries and caries types involving the root surface in elderly people were significantly associated with periodontal disease severity.

Effect of acrylonitrile content on compatibility and damping properties of hindered phenol AO-60/nitrile-butadiene rubber composites: molecular dynamics simulation

RSC Advances ◽  
2014 ◽  
Vol 4 (89) ◽  
pp. 48472-48479 ◽  
Author(s):  
Meng Song ◽  
Xiuying Zhao ◽  
Yi Li ◽  
Tung W. Chan ◽  
Liqun Zhang ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Molecular Dynamics Simulations ◽  
Dynamics Simulation ◽  
Butadiene Rubber ◽  
Damping Properties ◽  
Rubber Composites ◽  
Nitrile Butadiene Rubber ◽  
Hindered Phenol ◽  
Dynamics Simulations

By combining molecular dynamics simulations with experiment, the effect of acrylonitrile content on the compatibility and damping properties were investigated in the AO-60/nitrile-butadiene rubber composites.

scholarly journals The Relationship between Morphology, Colonial Appearance, Agglutinability, and Virulence to Mice of Certain Variants of Bacterium aertrycke

1930 ◽  
Vol 30 (1) ◽  
pp. 40-54 ◽  
Author(s):  
G. S. Wilson
Keyword(s):  
Virulent Strain ◽  
Type A ◽  
Type B ◽  
Smooth Form ◽  
Type D ◽  
Virulent Type ◽  
Type C ◽  
Transitional Forms ◽  
The One ◽  
The Relationship

1. Analysis of a series of 135 strains of B. aertrycke indicates that at least four well-defined types may be recognised on the basis of morphology, colonial formation, virulence to mice, and to a less extent agglutination by salt, serum, and acids. These types comprise: (i) type A—the normal smooth virulent form; (ii) type B—a smooth form of low virulence; (iii) type C—a roughish, so-called ichthyotic, form of low virulence; (iv) type D—the really rough avirulent form. Between these well-defined types certain transitional forms may sometimes be recognised, the virulence of which is frequently of an order intermediate between that of the A type on the one hand, and the B, C, or D types on the other.2. Evidence is brought to show that if a virulent strain is sub-cultured daily, under conditions known to lead to a fall in virulence of the whole culture, a gradual replacement occurs of the virulent type A bacilli by the avirulent B, C or D types. So long as an adequate proportion, which is very small, of type A bacilli persists in the culture the virulence of the whole culture remains fairly high; but when all type A bacilli have been replaced by bacilli of the B, C or D types the virulence of the whole culture falls considerably.

scholarly journals The effectiveness of TiO2 additions to mortar to maintain initial conditions in terms of its reflectance to solar radiation

2017 ◽  
Vol 17 (3) ◽  
pp. 39-56 ◽  
Author(s):  
Sérgio Roberto Andrade Dantas ◽  
Fulvio Vittorino ◽  
Kai Loh
Keyword(s):  
Solar Radiation ◽  
Ultraviolet Radiation ◽  
Initial Conditions ◽  
Type A ◽  
Just Noticeable Difference ◽  
Type B ◽  
Climate Conditions ◽  
Type D ◽  
Type C ◽  
Over Time

Abstract Contact of facades with degradation agents and direct incidence of ultraviolet radiation on external coatings make them more opaque over time, affecting their colour and reflectance characteristics. This study evaluated the effect of adding different TiO2 contents to mortars applied in concrete substrates in order to verify the reflectance maintenance on surfaces after exposure over time. Mortar with different concentrations of TiO2 (1%, 5%, 10%) were produced in relation to the total dry premix, added as a powder and compared to unpainted mortar without TiO2 (type "A") and painted mortar without TiO2 (type "B"), both used as a reference for colour and reflectance. Exposed over 16 months to climate conditions in São Paulo, regarding the maintenance of reflectance and solar radiation, the results showed that type "B" (0%TiO2) painted mortar presented the best performance. Type "C" (1%TiO2) and type "D" (5%TiO2) unpainted mortar remained more stable. Type "A" (0%TiO2) and type "E" (10%TiO2) unpainted mortar showed greater differences according to the Just Noticeable Difference (JND) range caused by dirt pick up.

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