Evolution of the Nanostructure and Viscoelastic Properties of Nitrile Rubber upon Mechanical Rejuvenation and Physical Aging

The influence of physical aging on mechanical properties of glassy polymers was investigated in this paper. After annealing above Tg to release the previous thermal and stress history, the polymethyl methacrylate (PMMA) samples were quenched to 27°C, aged for various times (ta), and were then stretched at the same temperature by two ways: (1) step stresses with four different magnitudes varying from 15MPa to 30MPa; (2) constant rate stretch up to fracture. The physical aging effect was monitored by measuring the initial instantaneous elastic modulus (E) and the fracture strength (σf) from the stress-strain curves as a function of ta up to 1368h. It is shown that both E and σf of the material increase with aging time and approach to their asymptotic values, which satisfy the KWW rule, while the isochronous creep compliance decreases with log ta in a linear manner within the aging time range considered in this paper.

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Dynamic viscoelastic properties of polyvinyl chloride with physical aging

Korea-Australia Rheology Journal ◽

10.1007/s13367-015-0026-8 ◽

2015 ◽

Vol 27 (4) ◽

pp. 259-266 ◽

Cited By ~ 1

Author(s):

Fang Tian ◽

Yingshe Luo ◽

Shuiping Yin ◽

Hong Wang ◽

Chun Cao

Keyword(s):

Polyvinyl Chloride ◽

Viscoelastic Properties ◽

Physical Aging

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Morphology, mechanical and viscoelastic properties of nitrile rubber/epoxidized natural rubber blends

Journal of Applied Polymer Science ◽

10.1002/app.21480 ◽

2005 ◽

Vol 97 (4) ◽

pp. 1561-1573 ◽

Cited By ~ 8

Author(s):

Asha Elizabeth Mathai ◽

Sabu Thomas

Keyword(s):

Natural Rubber ◽

Viscoelastic Properties ◽

Nitrile Rubber ◽

Epoxidized Natural Rubber ◽

Rubber Blends

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Payne Effect in Filled Nitrile Rubber Submitted to Cyclic Loadings

Volume 1: Advanced Computational Mechanics; Advanced Simulation-Based Engineering Sciences; Virtual and Augmented Reality; Applied Solid Mechanics and Material Processing; Dynamical Systems and Control ◽

10.1115/esda2012-82517 ◽

2012 ◽

Author(s):

Pierre P. Garnier ◽

Jean-Benoît J. B. Le Cam ◽

Michel M. Grédiac

Keyword(s):

Cyclic Loading ◽

Strain Amplitude ◽

Viscoelastic Properties ◽

Nitrile Rubber ◽

Loading Conditions ◽

Payne Effect ◽

Two Temperatures ◽

Loading Tests ◽

Number Of Cycles ◽

Cyclic Loading Tests

This study deals with the viscoelastic properties of filled nitrile rubber submitted to cyclic loading conditions. Classic strain amplitude sweeps were first carried out on both a filled and an unfilled nitrile rubber. Tests were performed at two temperatures ambient and 80 °C. Some specimens were then subjected to a high number of cycles to study the variations in the viscoelastic properties and the sensitivity of the Payne effect to cyclic loading tests at several given strain amplitudes.

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Alteration of matrix curing characteristics and its role in extension of hydrodynamic equation for predicting viscoelastic properties of nitrile rubber/silica nanocomposites

Polymers for Advanced Technologies ◽

10.1002/pat.4350 ◽

2018 ◽

Vol 29 (8) ◽

pp. 2381-2391

Author(s):

Mohammad Khabiri ◽

Seyed Hassan Jafari ◽

Mohammad Reza Pourhossainy ◽

Hossein Ali Khonakdar

Keyword(s):

Viscoelastic Properties ◽

Hydrodynamic Equation ◽

Nitrile Rubber ◽

Silica Nanocomposites ◽

Curing Characteristics

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Theoretical and Numerical Analysis of Anterior Cruciate Ligament Injury and its Prevention

Global Journal of Researches in Engineering ◽

10.34257/gjrejvol20is1pg43 ◽

2020 ◽

pp. 43-54

Author(s):

Lixiang Yang

Keyword(s):

Risk Factors ◽

Finite Element ◽

Anterior Cruciate Ligament ◽

Viscoelastic Properties ◽

Physical Aging ◽

Cruciate Ligament ◽

Acl Injury ◽

Polymer Materials ◽

Sport Activities ◽

Anterior Cruciate

Anterior cruciate ligament (ACL) injury is one of major risks for most athletes. ACL injury can be caused by many risk factors such as anatomic risk factors, biomechanical risk factors and environmental risk factors. In this article, numerical and theoretical analysis are conducted to investigate biomechanical risk factors. An entire three-dimensional finite element knee model was built based on MRI data. Anterior Tibial Translations (ATT) at different knee flexion angles are simulated by finite element models. In the simulations, more attentions are given to material properties of different knee components and their effects on ACL injury. Mechanical response of ACL during sport activities is highly determined by its viscoelastic properties. Unfortunately, viscoelastic properties of two bundles of ACL will change dramatically even with several hours’ physical aging. As a consequence, ACL will experience mechanical ductile to brittle transition due to daily physical aging. Theory of physical aging from polymer science is, for the first time, introduced to understand ACL injury and its prevention. By analogy to physical aging of amorphous polymer materials, we think physical aging of two bundles of ACL will largely increase risk of ACL injury. Besides, physical aging will also build a heterogeneous stress and strain in ACL due to its natural anatomic structure, which is a large risk for athletes. The specific designed prevention programs for ACL injury such as plyometrics, strengthening and other neuromuscular training exercises [1] are believed to erase physical aging of ACL. ACL with less physical aging is less likely to get injured in sport activities. In this article, a virtual physical aging simulation is built to validate current hypothesis. Erasing physical aging of ACL may provide an accurate and quantitative way to prevent ACL injury.

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