Dynamic Mechanical and Electrical Properties of Vulcanizates at Elongations up to Sample Rupture

1974 ◽  
Vol 47 (4) ◽  
pp. 765-777 ◽  
Author(s):  
A. Voet ◽  
J. C. Morawski
Keyword(s):  
Carbon Black ◽  
Dynamic Stress ◽  
Dynamic Properties ◽  
Mullins Effect ◽  
Dynamic Moduli ◽  
Low Frequencies ◽  
Mechanical And Electrical Properties ◽  
Conductance Data ◽  
Filler Network ◽  
Small Deformations

Abstract Dynamic properties of vulcanizates have been measured at small and large extensions, up to specimen rupture, by means of a modified Rheovibron. The influence of temperature, frequency, and amplitude on the dynamic moduli has been determined for a number of SBR samples, uncharged or charged with silica or carbon black. A study has been made of the dynamic Mullins effect (stress-softening) and of dynamic stress-relaxation for various charged and uncharged samples. Electrical conductivity has been determined simultaneously with dynamic properties for carbon-black loaded elastomers. The gradual reformation of a previously destroyed secondary filler network could be followed quantitatively in rate and magnitude at very low frequencies. It appears that at small deformations a secondary, reversible filler network plays an important part in the dynamic properties of the vulcanizates. At intermediate deformations, however, this network has been eliminated. Conductance data of carbon-black loaded vulcanizates indicate a phenomenon of orientation of anisometric aggregates. At still higher deformations irreversible changes are observed, pointing to a rupture in filler—elastomer bonds as well as of elastomer chains, two experimentally distinguishable phenomena.

Effect of Carbon Black on Dynamic Properties of Rubber Vulcanizates

1978 ◽  
Vol 51 (3) ◽  
pp. 437-523 ◽  
Author(s):  
A. I. Medalia
Keyword(s):  
Carbon Black ◽  
Vibration Isolation ◽  
Power Transmission ◽  
Dynamic Properties ◽  
Engineering Application ◽  
Mullins Effect ◽  
Rubber Compounds ◽  
Background Material ◽  
Power Transmission Belts ◽  
Transient Forces

Abstract The term dynamic properties as applied to elastomers refers to the response to periodic or transient forces which do not cause failure or appreciable fatigue (permanent change of properties) during the investigation. Generally this is limited to vulcanizates subjected to deformations not exceeding about 25%; and generally the dynamic properties are measured after several cycles or (in a transient experiment such as resilience) after several preconditioning transients, so that the Mullins effect or difference between first and second strain cycles is not of consequence. Thus, dynamic properties represent the viscoelastic properties of vulcanizates at deformations below about 25%, after reaching a pseudo-equilibrium state. The dynamic properties of rubber are altered tremendously by the addition of a filler. The scope of this article is restricted to the dynamic properties of rubber vulcanizates with carbon black as a filler. The effect covered in this article are important in designing rubber compounds to be used under dynamic conditions, such as tires, power transmission belts, vibration isolation mountings, etc. However, the engineering application of dynamic properties, which has been treated in detail elsewhere, is outside the scope of this review. A certain amount of background material is needed. We will first define the terms used in describing dynamic properties. The methods and instruments used for measuring these properties will be described briefly, and the nature of carbon black will be reviewed. Finally, some historical material is given, together with the dynamic behavior of typical compounds, as a preface to the review of more recent work in this field.

CORRELATION OF FILLER NETWORKING WITH REINFORCEMENT AND DYNAMIC PROPERTIES OF SSBR/CARBON BLACK/SILICA COMPOSITES

2015 ◽  
Vol 88 (4) ◽  
pp. 676-689 ◽  
Author(s):  
Wengjiang Feng ◽  
Zhenghai Tang ◽  
Peijin Weng ◽  
Baochun Guo
Keyword(s):  
Carbon Black ◽  
Network Structure ◽  
Dynamic Properties ◽  
Rolling Resistance ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Rubber Composites ◽  
Filler Network ◽  
Improved Performance ◽  
Styrene Butadiene

ABSTRACT The use of silica to partially replace carbon black is a common practice in the fabrication of “green tires.” Although some degree of consensus has been approached concerning the improved performance conferred by silica substitution, such as the improved dispersion of carbon black, a quantitative understanding of the relationship between filler networking and the performance of rubber composites has not been established. Thus, an investigation focusing on filler network structure and the correlation between the network structure and the reinforcement of rubber composites was conducted. We prepared solution-polymerized styrene–butadiene rubber (SSBR) reinforced by carbon black and carbon black/silica in different ratios. To exclude as much of the effect from changed crosslinking, and figure out how filler blending influences filler dispersion and filler network structure, the silane generally used in the tire industry was not adopted. The quantitative predictor, the mass fractal dimension df, was derived from the Kraus model and the Huber–Vilgis model. We found that when the amount of substituted silica increases, the filler cluster branching decreases, accompanied by increased reinforcement efficiency. The depressed filler networking induced by silica substitution at an appropriate proportion leads to improved dynamic properties, including lower rolling resistance and better wet skid. When the silica proportion in the filler is too high, severe filler networking is observed, resulting in decreased reinforcing efficiency and impaired dynamic properties.

scholarly journals Effect Of Carbon Black Loading On Linear Low-Density Polyethylene Properties

2021 ◽  
Author(s):  
Noora Al-Qahtani ◽  
Maryam Al-Ejji ◽  
Mabrouk Ouederni ◽  
Mariam AlMaadeed ◽  
Nabil Madi
Keyword(s):  
Carbon Black ◽  
Morphological Properties ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Low Frequencies ◽  
Shear Rates ◽  
Carbon Particles ◽  
Mechanical And Electrical Properties ◽  
High Shear Rates

Abstract The mechanical, thermal, electrical, reheology, and morphological properties of composites made from linear low-density polyethylene and carbon black (CB) content of 5%, 10%, and 20% by weight were investigated. The optimum mechanical and electrical properties performance was achieved with the adding of 5% carbon black. The drop in properties after adding more CB is due to agglomeration and poor dispersion of carbon particles in the polymer matrix. CB resulted in higher dynamic viscosity and storage modulus at low frequencies, although this phenomenon was reversed at high frequencies. CB resulted in more shear thinning of LLDPE at high shear rates.

The Effect of Compositional and Testing Variations on the Dynamic Properties of Compounds Based on Styrene-Butadiene and Polybutadiene Elastomers

1971 ◽  
Vol 44 (1) ◽  
pp. 258-270 ◽  
Author(s):  
D. A. Meyer ◽  
J. G. Sommer
Keyword(s):  
Carbon Black ◽  
Storage Modulus ◽  
Dynamic Properties ◽  
Loss Modulus ◽  
Dynamic Stiffness ◽  
Rate Of Change ◽  
Complex Dynamic ◽  
Spring Rate ◽  
Styrene Butadiene ◽  
Black Level

Abstract Important factors of potential use for manipulating static and dynamic stiffness and the damping characteristics of compounds based on styrene-butadiene and polybutadiene elastomers and their blends have been outlined. Their characteristics have been compared with those of IIR and EPDM compounds. The effects of variations in composition are quantitatively defined to assist the compounder in combining these effects in a manner that will lead to a desired combination of properties. In addition to the expected increase in static spring rate and dynamic spring rate with carbon black level, the following responses to compositional variations were found important: 1. The complex dynamic spring rate is more sharply dependent upon carbon black level than the static spring rate. 2. The complex dynamic spring rate is essentially independent of the level of crosslinking while static spring rate increases. 3. Damping coefficient is directly proportional to the level of carbon black and inversely proportional to the level of crosslinking. 4. Styrene level in a polymer blend and plasticizer composition can be used to adjust loss modulus and storage modulus at a given temperature and also to modify the rate of change of these properties with temperature. 5. The strain dependency of storage modulus was found in one instance to vary with the elastomer composition. The IIR vulcanizate, when formulated to the same static modulus, exhibited a larger strain dependence than the SBR, BR, and EPDM composition.

scholarly journals Mechanism of HCB-Modified Asphalt and Dynamic Properties of Mixtures

2020 ◽  
Vol 10 (14) ◽  
pp. 4971
Author(s):  
Zhan Ding ◽  
Jinfei Su ◽  
Peilong Li ◽  
Hui Bing
Keyword(s):  
Functional Groups ◽  
Oxygen Content ◽  
Performance Test ◽  
Dynamic Properties ◽  
Chemical Properties ◽  
Active Surface ◽  
Asphalt Mixtures ◽  
Low Frequencies ◽  
High Oxygen Content ◽  
Modified Asphalt

Hydroxymethyl carbon black (HCB) was prepared as an asphalt modifier with a high oxygen content and active surface chemical properties. The microstructure of HCB was analyzed by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier-transform infrared spectroscopy. The improvement effect of HCB on asphalt’s physical, dynamic shear, rheological, and aging properties was evaluated. To analyze the dynamic properties of the HCB-modified asphalt mixtures, a simple performance test (SPT) was conducted, and then the change laws of the dynamic modulus and phase angle for the HCB mixtures were clarified. The results showed that the surface of HCB is smooth and that the oxygen content increases with the generation of hydroxyl functional groups. Polar oxygen-containing functional groups and hydrogen bonds are helpful in improving the resistance to cracking and aging. The surface activity of HCB is susceptible to temperature and frequency, causing a slight influence of HCB on the viscoelasticity of asphalt mixtures at high and low frequencies. At low temperatures and high frequencies, the HCB enhanced the elasticity characteristics and weakened the viscosity characteristics of asphalt mixtures.

scholarly journals Dynamic stress relaxation in carbon black filled vulcanizates.

1986 ◽  
Vol 59 (5) ◽  
pp. 282-289
Author(s):  
Kunihiko FUJIMOTO ◽  
Hidehiko AKIMOTO
Keyword(s):  
Stress Relaxation ◽  
Carbon Black ◽  
Dynamic Stress
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