Thermomechanical Degradation of SBR During Ultrasonic Treatment under the Static Conditions

V. V. Yashin; C. K. Hong; A. I. Isayev

doi:10.5254/1.3547814

Thermomechanical Degradation of SBR During Ultrasonic Treatment under the Static Conditions

Rubber Chemistry and Technology ◽

10.5254/1.3547814 ◽

2004 ◽

Vol 77 (1) ◽

pp. 50-77 ◽

Cited By ~ 7

Author(s):

V. V. Yashin ◽

C. K. Hong ◽

A. I. Isayev

Keyword(s):

Ultrasonic Treatment ◽

Theoretical Calculations ◽

Structural Characteristics ◽

Continuous Process ◽

Styrene Butadiene Rubber ◽

Butadiene Rubber ◽

Ultrasonic Power ◽

Rubber Layer ◽

Static Conditions ◽

Styrene Butadiene

Abstract The paper presents the results of experimental and theoretical studies of the ultrasonic treatment of ground vulcanized unfilled styrene-butadiene rubber (SBR) in a static device (no flow). Degradation of the rubber network took place during the treatment. Crosslink density and gel fraction were measured in the samples ultrasonically treated at various pressures, ultrasonic amplitudes and exposure times. Consumption of the ultrasonic energy was also monitored. The structural characteristics of SBR ultrasonically treated under static conditions have been found to be significantly different from those reported previously for the continuous process. Theoretical calculations have demonstrated that the observed differences could be attributed to a partial depolymerization of broken rubber chains caused by a significant temperature rise in the course of ultrasonic treatment under static conditions. It has also been shown that the non-linearity of compressibility of a thin ground rubber layer has to be taken into account in the calculations of ultrasonic power consumption.

Download Full-text

Structure and properties of ultrasonically extruded SBR/BR blends and prepared compounds and vulcanizates with various fillers

Journal of Elastomers & Plastics ◽

10.1177/0095244318804597 ◽

2018 ◽

Vol 51 (7-8) ◽

pp. 603-625 ◽

Cited By ~ 1

Author(s):

Tian Liang ◽

Avraam I Isayev

Keyword(s):

Molecular Weight ◽

Loss Tangent ◽

Ultrasonic Treatment ◽

Rolling Resistance ◽

Styrene Butadiene Rubber ◽

Butadiene Rubber ◽

Ultrasonic Power ◽

Elongation At Break ◽

Single Screw Extruder ◽

Styrene Butadiene

The ultrasonic treatment of styrene-butadiene rubber (SBR)/butadiene rubber (BR) 50/50 blend in single screw extruder was carried out at amplitudes up to 10 μm. The untreated and treated SBR/BR blends were mixed with carbon black (CB), silica, and silica/silane to prepare 50/50/60 compounds. It was found that ultrasonic power consumption increased and die pressure reduced with the increase of ultrasonic amplitude, indicating a potential to increase extrusion output rate with the aid of ultrasound. Molecular weight of blends treated at 3.5 μm increased, and high molecular weight tail was observed at 5, 7.5, and 10 μm. Solvent extraction experiments showed the formation of gel in blends treated at 7.5 and 10 μm. No gel was observed in blends untreated and treated at 3.5 and 5 μm. SBR/BR/silica vulcanizates prepared from the blend treated at 5 μm showed the reduced loss tangent at −30°C, 0°C, and 60°C, predicting a lower snow, wet traction, and rolling resistance. Reduced loss tangent after ultrasonic treatment was a result of reduced filler flocculation. The tensile strength and elongation at break of all treated SBR/BR and SBR/BR/CB vulcanizates treated at 3.5 and 5 μm increased. Modulus 100% elongation (M100) of vulcanizates prepared from SBR/BR/silica treated at 5 μm was also increased.

Download Full-text

A Model for Rubber Degradation under Ultrasonic Treatment: Part I. Acoustic Cavitation in Viscoelastic Solid

Rubber Chemistry and Technology ◽

10.5254/1.3538831 ◽

1999 ◽

Vol 72 (4) ◽

pp. 741-757 ◽

Cited By ~ 30

Author(s):

V. V. Yashin ◽

A. I. Isayev

Keyword(s):

Static Pressure ◽

Ultrasonic Attenuation ◽

Degradation Process ◽

Styrene Butadiene Rubber ◽

Butadiene Rubber ◽

Ultrasonic Power ◽

Maximal Level ◽

Viscoelastic Solid ◽

Styrene Butadiene ◽

Rubber Degradation

Abstract The physics of rupture of a rubber network under the action of powerful ultrasound is considered. It is assumed that rubber degradation occurs mainly around pulsating microcavities (bubbles) usually present in rubbers. The maximal level of strain is attained in the vicinity of these cavities. A Lodge-like model of finite viscoelasticity is utilized to describe the strain profile around the vibrating cavity at a given ultrasonic pressure. Network degradation rate is taken to be proportional to the number of overstressed network chains. Detailed analysis is given for the case of a thin layer of cured rubber placed between an ultrasonic horn and a die and subjected to static pressure. Ultrasonic pressure in the layer is shown to depend on the thickness of the layer with its value found to be higher than that in the bulk. The static pressure is found to increase the ultrasonic power consumption and to enhance the degradation process. This is due to a decrease in compressibility of the bubbly media leading to a reduction in the ultrasonic attenuation. Calculations are carried out using styrene-butadiene rubber as an example.

Download Full-text

Mechanical and Dynamic Behavior of an Elastic Rubber Layer with Recycled Styrene-Butadiene Rubber Granules

Polymers ◽

10.3390/polym12123022 ◽

2020 ◽

Vol 12 (12) ◽

pp. 3022

Author(s):

Seongdo Kim ◽

Hyun-Oh Shin ◽

Doo-Yeol Yoo

Keyword(s):

Tensile Properties ◽

Curing Temperature ◽

Styrene Butadiene Rubber ◽

Butadiene Rubber ◽

Test Results ◽

Elongation At Break ◽

Curing Conditions ◽

Rubber Layer ◽

Elastic Rubber ◽

Styrene Butadiene

This study evaluates the tensile properties, including the tensile strength and elongation at break, and dynamic behavior, including shock absorption and vertical deformation, of an elastic rubber layer in synthetic sports surfaces produced using waste tire chips containing styrene-butadiene rubber (SBR). The primary variables of the investigation were the number of compactions, resin–rubber granule ratio, and curing conditions, such as aging, the temperature, and the relative humidity. The test results showed an increase in the tensile strength of the elastic rubber layer with recycled SBR as the number of compactions, resin–rubber granule ratio, curing period, and temperature increased, while the elongation at break was affected by the curing temperature and period. Shock absorption and vertical deformation decreased with an increasing resin–rubber granule ratio and number of compactions due to the increased hardness. However, these properties were not significantly affected by the curing conditions. Furthermore, the test results indicated that the curing temperature has a pronounced effect on the tensile properties of the elastic rubber layer, and maintaining the appropriate curing temperature—approximately 50 °C—is a possible solution for improving the relatively low tensile properties of the elastic rubber layer.

Download Full-text

MOLECULAR TREATMENT OF RUBBER-LIKE ELASTICITY FOR ACTIVE FILLER–LOADED NETWORKS

Rubber Chemistry and Technology ◽

10.5254/rct.15.84884 ◽

2015 ◽

Vol 88 (4) ◽

pp. 640-659 ◽

Cited By ~ 4

Author(s):

Yoshio Hoei

Keyword(s):

Filler Particle ◽

Finite Extension ◽

Styrene Butadiene Rubber ◽

Chain Model ◽

Butadiene Rubber ◽

Single Chain ◽

Rubber Layer ◽

Bound Rubber ◽

Styrene Butadiene ◽

Further Development

ABSTRACT Prior comparison of experimental observations and model predictions for natural rubber/styrene–butadiene rubber carbon black–filled systems has indicated a need for further development of tubelike constraint-based entropy models. In particular, systems incorporating active fillers introduce constraints whose effects should be considered. This contribution extends the finite-extension single-chain model proposed originally by Teramoto, via consideration of the bound rubber layer surrounding a filler particle as well as filler-cluster breakup and strain-amplification effects. The resulting model includes descriptors of the entropy state of the polymer matrix, the affine and phantomlike chain deformation, and tube diameter. The model produced a more accurate prediction of the shape of observed stress–strain curves, particularly at moderate and high strains.

Download Full-text