Characterization of polymers in large deformation by repeated chemical stress relaxation of vulcanized rubbers

Abstract In this investigation, repeated chemical stress relaxation measurements were carried out to observe the relaxation behavior at large deformation. It was found that the repeated chemical stress relaxation curves were affected by both measurement temperature and the extension ratio of rubber. It was suggested on the basis of the results that temperature and mechanical stimulus have a similar effect on the stress relaxation curves.

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Characterization of polymers under large deformation. I. Repeated chemical stress relaxation of vulcanized rubbers

Journal of Polymer Science Part A-1 Polymer Chemistry ◽

10.1002/pol.1972.170101001 ◽

1972 ◽

Vol 10 (10) ◽

pp. 2823-2831 ◽

Cited By ~ 4

Author(s):

Takae Kusano ◽

Kenkichi Murakami

Keyword(s):

Stress Relaxation ◽

Large Deformation ◽

Chemical Stress

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Characterization of the Large Deformation Plasticity of Pure Lithium Foil

10.26226/morressier.5f5f8e69aa777f8ba5bd5fe8 ◽

2020 ◽

Author(s):

Juner Zhu

Keyword(s):

Large Deformation ◽

Deformation Plasticity

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Stress relaxation and optical characterization of TiO2 and SiO2 films grown by dual ion beam deposition

Thin Solid Films ◽

10.1016/j.tsf.2008.06.032 ◽

2008 ◽

Vol 516 (23) ◽

pp. 8604-8608 ◽

Cited By ~ 24

Author(s):

C. Bundesmann ◽

I.-M. Eichentopf ◽

S. Mändl ◽

H. Neumann

Keyword(s):

Stress Relaxation ◽

Ion Beam ◽

Optical Characterization ◽

Sio2 Films ◽

Ion Beam Deposition ◽

Beam Deposition

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Chemical Stress Relaxation of NR Networks Prepared in the Swollen State

Rubber Chemistry and Technology ◽

10.5254/1.3538216 ◽

1986 ◽

Vol 59 (4) ◽

pp. 541-550 ◽

Cited By ~ 1

Author(s):

Kyung-Do Suh ◽

Hidetoshi Oikawa ◽

Kenkichi Murakami

Keyword(s):

Stress Relaxation ◽

Network Structure ◽

Three Dimensional ◽

Polymer Chains ◽

Chemical Stress ◽

Network Chain ◽

Crosslinking Process ◽

Dimensional Network ◽

Chemical Relaxation ◽

The Difference

Abstract From the experimental results of the present investigation, it is apparent that two kinds of networks which have a different three-dimensional network structure give quite different behavior of chemical stress relaxation, even if both networks have the same network chain density. The difference in three-dimensional network structure for the two kinds of rubber arises from the degree of entanglement, which changes with the concentration of the polymer chains prior to the crosslinking process. The direct cause of chemical relaxation is due to the scission of network chains by degradation, whereas the total relaxation is caused by the change of geometrical conformation of network chains. This then casts doubt on the basic concept of chemorheology which is represented by Equation 2.

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Mechanical properties of the tadpole tail fin

Journal of Experimental Biology ◽

10.1242/jeb.201.19.2691 ◽

1998 ◽

Vol 201 (19) ◽

pp. 2691-2699 ◽

Cited By ~ 2

Author(s):

PA Doherty ◽

RJ Wassersug ◽

JM Lee

Keyword(s):

Stress Relaxation ◽

Large Deformation ◽

Forced Vibration ◽

Viscoelastic Properties ◽

Developmental Plasticity ◽

Rana Catesbeiana ◽

Small Deformation ◽

Collagen Fibres ◽

Tadpole Tail ◽

Undulatory Swimming

The tadpole tail fin is a simple double layer of skin overlying loose connective tissue. Collagen fibres in the fin are oriented at approximately +/-45 degrees from the long axis of the tail. Three tests were conducted on samples of the dorsal tail fin from 6-10 Rana catesbeiana tadpoles to establish the fin's viscoelastic properties under (1) large-deformation cyclic loading at 1 and 3 Hz, (2) small-deformation forced vibration at 1 and 3 Hz, and (3) stress relaxation under a 0.1 s loading time. The fin was very fragile, failing easily under tensile loads less than 7 g. It was also strikingly viscoelastic, as demonstrated by 72+/-1 % hysteresis loss (at 3 Hz), 16+/-3 % stress remaining after 100 s of stress relaxation and a phase angle of 18+/-1 degrees in forced vibration. As a consequence of its viscoelastic properties, the fin was three times stiffer in small than in large deformation. This may account for the ability of the fin to stay upright during normal undulatory swimming, despite the absence of any skeletal support. Tadpoles in nature are often found with damaged tails. We suggest that the unusually viscoelastic and fragile nature of the fin helps tadpoles escape the grasp of predators. Because the fin deforms viscoelastically and tears easily, tadpoles can escape predators and survive otherwise lethal attacks with only minor lacerations to the fin. Recent studies have shown that certain tadpoles develop taller fins in the presence of predators. This developmental plasticity is consistent with the tail fin acting as a protective but expendable 'wrap' around the core muscle tissue.

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Longitudinal Cracking in a Carbon Black Filled Natural Rubber Vulcanizate during Chemical Stress Relaxation

Rubber Chemistry and Technology ◽

10.5254/1.3538477 ◽

1998 ◽

Vol 71 (2) ◽

pp. 157-167 ◽

Cited By ~ 5

Author(s):

G. R. Hamed ◽

J. Zhao

Keyword(s):

Stress Relaxation ◽

Carbon Black ◽

Natural Rubber ◽

Longitudinal Crack ◽

Chemical Stress ◽

Loading Direction ◽

Rubber Vulcanizate ◽

Edge Cracks ◽

Forced Air ◽

Oxidative Attack

Abstract Thin specimens of a black-filled, natural rubber vulcanizate have been held in uniaxial tension at 72°C and 200% elongation in a forced air oven. After substantial oxidative attack (inferred from stress relaxation), small edge cracks formed. Initially, these cracks grew perpendicular to the loading direction, but, upon reaching about 0.1 mm in depth, longitudinal crack growth commenced and fracture progressed by a kind of 0°-peel process with “splitting-off” of successive strands of rubber. This phenomenon is attributed to anisotropy in strength caused both by straining and by oxidative attack.

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