Cure and Mechanical Behavior of Rubber Compounds Containing Ground Vulcanizates: Part III. Tensile and Tear Strength

1999 ◽  
Vol 72 (2) ◽  
pp. 357-360 ◽  
Author(s):  
D. Gibala ◽  
D. Thomas ◽  
G. R. Hamed
Keyword(s):  
Tensile Testing ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Composite Matrix ◽  
Stick Slip ◽  
Tear Strength ◽  
Ground Rubber ◽  
Rubber Compounds ◽  
Styrene Butadiene ◽  
Crack Tip Blunting

Abstract A black-filled styrene-butadiene rubber (SBR) vulcanizate was ambiently ground, then used as an additive to the original, uncured compound. Sheets of the resulting composite (matrix/ground rubber particulate) were cured, and tensile and trouser tear strength determined. The composite had reduced tensile strength, but enhanced tear strength relative to the original vulcanizate. The contrasting behavior is attributed to the effects of sulfur migration into the particulate rubber and differences in the responses of a tensile and a tear testpiece to discontinuities. In brief, ground rubber acts as a stress-raising flaw in tensile testing, while promoting crack tip blunting and stick-slip behavior in trouser tearing.

scholarly journals Insights into the Payne Effect of Carbon Black Filled Styrene-butadiene Rubber Compounds

2020 ◽  
Vol 39 (1) ◽  
pp. 81-90
Author(s):  
An Zhao ◽  
Xuan-Yu Shi ◽  
Shi-Hao Sun ◽  
Hai-Mo Zhang ◽  
Min Zuo ◽  
...  
Keyword(s):  
Carbon Black ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Payne Effect ◽  
Rubber Compounds ◽  
Styrene Butadiene

Thermal conductivity of styrene butadiene rubber compounds with natural rubber prophylactics waste as filler

1999 ◽  
Vol 35 (9) ◽  
pp. 1687-1693 ◽  
Author(s):  
N.S. Saxena ◽  
P. Pradeep ◽  
G. Mathew ◽  
S. Thomas ◽  
M. Gustafsson ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Natural Rubber ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Rubber Compounds ◽  
Styrene Butadiene

scholarly journals Microwave Devulcanized Crumb Rubbers in Polypropylene Based Thermoplastic Dynamic Vulcanizates

Polymers ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 767 ◽  
Author(s):  
Dániel Simon ◽  
István Halász ◽  
József Karger-Kocsis ◽  
Tamás Bárány
Keyword(s):  
Processing Parameters ◽  
Crumb Rubber ◽  
Partial Substitution ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Feeding Method ◽  
Rubber Compounds ◽  
Continuous Extrusion ◽  
3D Molecular Structure ◽  
Styrene Butadiene

Because of the chemically crosslinked 3D molecular structure of rubbers, their recycling is a challenging task, especially when cost efficiency is also considered. One of the most straightforward procedures is the grinding of discarded rubber products with subsequent devulcanization. The devulcanized rubber can be used as a feedstock for fresh rubber compounds or can be blended with uncured virgin rubber and thermoplastic polymers to form thermoplastic dynamic vulcanizates (TDVs). TDVs combine the beneficial (re)processability of thermoplastics and the elastic properties of rubbers. Our current work focuses on the development of polypropylene (PP)-based TDVs with the use of a tire model rubber (MR) composed of natural rubber (NR) and styrene-butadiene rubber (SBR) in a ratio of 70/30. The research target was the partial substitution of the above fresh MR by microwave devulcanized crumb rubber (dCR). TDVs were produced by continuous extrusion, and the effects of composition (PP/MR/dCR = 40/60/0…50/35/15) and processing parameters (different screw configurations, temperature profiles, the feeding method of PP) were investigated. Results showed that the fresh rubber compound can be replaced up to 10 wt % without compromising the mechanical properties of the resulting TDV.

Higher tear strength of EPDM/SBR/TPR composites foam based on double foaming system

2020 ◽  
pp. 009524432093398
Author(s):  
Fuquan Deng ◽  
Hua Jin ◽  
Li Zhang ◽  
Yuxin He
Keyword(s):  
Cell Size ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Polymeric Foam ◽  
Tear Strength ◽  
Crystallization Property ◽  
Plastic Foams ◽  
Styrene Butadiene

Polymeric foam with lightweight and higher impact strength has been used in many fields due to cost reduction and higher toughness. However, it is often difficult to improve their mechanical property especially tear strength. Here, a double foaming system was designed to increase the tear strength of the foamed ethylene–propylene–diene monomer, styrene–butadiene rubber, and thermoplastic rubber (EPDM/SBR/TPR) materials. The cell size of EPDM/SBR/TPR foam and cell distribution were investigated by scanning electron microscopy, which showed that the cells present a bimodal structure. Besides, the tear strength can reach up to 10 N/mm when the density is about 0.40 g/cm3, which is much superior to those of most engineering plastic foams. Meanwhile, the crystallization property of EPDM/SBR/TPR foams was also demonstrated by X-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry, which indicates that the double foaming system can reduce the crystallization of EPDM/SBR/TPR molecular chains. In addition, the variation of thermal conductivity values depends on the gradual decrease effect of the cell size.

scholarly journals Organic Zinc Salts as Pro-Ecological Activators for Sulfur Vulcanization of Styrene–Butadiene Rubber

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1723 ◽  
Author(s):  
Magdalena Maciejewska ◽  
Anna Sowińska ◽  
Judyta Kucharska
Keyword(s):  
Zinc Oxide ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Zinc Ions ◽  
Organic Zinc ◽  
Rubber Compounds ◽  
Curing Characteristics ◽  
Sulfur Vulcanization ◽  
Zinc Salts ◽  
Styrene Butadiene

Organic zinc salts and complexes were applied as activators for sulfur vulcanization of styrene–butadiene elastomer (SBR) in order to reduce the content of zinc ions in rubber compounds as compared with conventionally used zinc oxide. In this article, the effects of different organic zinc activators on the curing characteristics, crosslink densities, and mechanical properties of SBR as well as the aging resistance and thermal behavior of vulcanizates are discussed. Organic zinc salts seem to be good substitutes for zinc oxide as activators for sulfur vulcanization of SBR rubber, without detrimental effects to the vulcanization time and temperature. Moreover, vulcanizates containing organic zinc salts exhibit higher tensile strength and better damping properties than vulcanizate crosslinked with zinc oxide. The application of organic zinc activators allows the amount of zinc ions in SBR compounds to be reduced by 70–90 wt % compared to vulcanizate with zinc oxide. This is very important for ecological reasons, since zinc oxide is classified as being toxic to aquatic species.

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