Influence of Aggregate Structure and Matrix Infiltration on the Dispersion Behavior of Carbon Black Agglomerates

1995 ◽  
Vol 68 (5) ◽  
pp. 836-841 ◽  
Author(s):  
Qi Li ◽  
D. L. Feke ◽  
I. Manas-Zloczower
Keyword(s):  
Carbon Black ◽  
Critical Stress ◽  
Stress Conditions ◽  
Degree Of Saturation ◽  
Aggregate Structure ◽  
Dispersion Process ◽  
Dimethyl Siloxane ◽  
The Matrix ◽  
High Structure ◽  
Kinetics Of

Abstract The dispersion of carbon black agglomerates in poly(dimethyl siloxane) (PDMS) has been studied experimentally. Both the structure of carbon black aggregates comprising the agglomerate and the presence of the matrix within the agglomerate were found to affect the mode of dispersion, critical stress conditions, and the kinetics of the dispersion process. Agglomerates of high structure carbon black are generally more difficult to disperse than agglomerates of low structure carbon black at the same agglomerate density. Depending on the degree of saturation of the agglomerate by PDMS, the dispersion process may be either enhanced or retarded compared to the dry state.

Effect of Mechanical Shear on the Structure of Carbon Black in Reinforced Elastomers

1970 ◽  
Vol 43 (5) ◽  
pp. 943-959 ◽  
Author(s):  
A. M. Gessler
Keyword(s):  
Molecular Weight ◽  
Carbon Black ◽  
Related Result ◽  
Critical Factor ◽  
Aggregate Structure ◽  
Carbon Black Concentration ◽  
Roll Mill ◽  
Total Structure ◽  
High Structure ◽  
High Shearing

Abstract The primary aggregate structure in high structure blacks is broken down when the blacks are milled in rubber. The breakdown, it is shown further, involves the disruption initially of more easily disrupted forces, and then subsequently of more difficultly disrupted forces. If the total structure breakdown is segmented accordingly, one finds that carbon blacks differ markedly in the proportion of the breakdown which occurs in each segment. But only the breakage of more difficultly disrupted structure is identified with chemical changes in the black and with concomitantly increased carbon—polymer interaction activity, i.e., with enhanced reinforcement. In studying the breakage of aggregate black structure which occurs when the blacks are milled in rubber, the following factors are considered: (1) Carbon Black Concentration: Breakage increases continuously, though not steadily, with carbon black concentration. This result is used to emphasize the merits of concentrated black masterbatching as the means for producing high quality products from SBR, BR, and EPDM rubbers. (2) Carbon Black Structure: Taking the total structure breakage over a broad range of carbon black concentrations, the extent of the breakage increases with the extent of the primary aggregate structure in the original black. (3) Polymer Viscosity or Molecular Weight: The extent to which breakage occurs on milling increases with the polymer viscosity or molecular weight. Since this result clearly cites the need for high shearing forces during milling, the severe limitations which must attend the use of plasticizing oils is implied. (4) Open Mill vs Banbury Mixing: The extent to which breakage occurs in the Banbury is significantly less than that on the two roll mill. Evidence is presented to show that this, clearly, is a temperature related result and, as in (3) above, that the magnitude of the shearing forces is the critical factor.

Filler Phase Distribution in Rubber Blends Characterized by Thermogravimetric Analysis of the Rubber-Filler Gel

2008 ◽  
Vol 81 (5) ◽  
pp. 767-781 ◽  
Author(s):  
H. H. Le ◽  
S. Ilisch ◽  
G. R. Kasaliwal ◽  
H-J. Radusch
Keyword(s):  
Thermogravimetric Analysis ◽  
Carbon Black ◽  
Phase Distribution ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Rubber Blends ◽  
The Matrix ◽  
Kinetics Of ◽  
Wetting Rate ◽  
Rubber Filler

Abstract The analysis of the rubber-filler gel of carbon black filled rubber compounds and blends provides useful information about the mixing process taking place inside the internal mixer. A new measure technique named wetting rate was introduced to describe the wetting behavior of the rubber onto the filler. Natural rubber (NR)/styrene-butadiene rubber (SBR) blends has been used for experimental investigation. NR shows a significantly higher wetting rate than SBR. The wetting rate does not only depend on the viscosity of rubber but strongly on the functionalization of it. Using the data determined from the thermogravimetric analysis (TGA) of rubber-filler gel, a new method was developed to characterize the kinetics of carbon black (CB) localization in the phases of heterogeneous rubber blends. During the first mixing stage, the CB localization is affected strongly by the wetting rate ratio of the blend components. In the second mixing stage, the rubber-filler interaction dominantly influences the distribution kinetics of the filler to the phases. Because of the higher wetting rate of the NR component, in the investigated NR/SBR blends more CB is found in the NR phase than in the SBR phase. The effect of the matrix viscosity and polarity on the phase specific CB distribution was systematically investigated.

EFFECT OF CURING ADDITIVES ON THE DISPERSION KINETICS OF CARBON BLACK IN RUBBER COMPOUNDS)

2011 ◽  
Vol 84 (3) ◽  
pp. 415-424 ◽  
Author(s):  
H. H. Le ◽  
S. Ilisch ◽  
E. Hamann ◽  
M. Keller ◽  
H-J. Radusch
Keyword(s):  
Carbon Black ◽  
Stearic Acid ◽  
Electrical Conductance ◽  
Rubber Matrix ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Dispersion Process ◽  
Styrene Content ◽  
Styrene Butadiene ◽  
Kinetics Of

Abstract The effect of curing additives on the dispersion kinetics of carbon black (CB) in styrene butadiene rubber (SBR) compounds was investigated by means of the method of the online measured electrical conductance. Addition of curing additives such as stearic acid and diphenylguanidine (DPG) accelerates the CB dispersion process significantly. The viscosity of the rubber matrix was not changed after their addition. The addition of stearic acid and DPG may alter the filler–filler interaction that consequently leads to faster dispersion processes. The obtained difference in morphologies of SBR mixtures containing stearic acid and DPG, respectively, are caused by their different infiltration behavior, which may lead to different dispersion mechanisms. Addition of ZnO could not improve the dispersion process of CB because of its limited interaction with CB. Sulfur and N-cyclohexylbenzothiazole-2-sulfenamide decelerate the CB dispersion process. The strong effect of the rubber microstructure such as styrene content and molecular weight on the CB dispersion in SBR mixtures without additives was found and discussed by taking into consideration the known dispersion mechanisms. The influence of addition of curing additives on the CB dispersion in low styrene-content SBR mixtures is much more pronounced than that in high styrene-content SBR mixtures.

High-resolution observations of metastable γ’ precipitation in Al-15at.%Ag

1996 ◽  
Vol 54 ◽  
pp. 1004-1005
Author(s):  
N. V. Larcher ◽  
I. G. Solorzano
Keyword(s):  
Discontinuous Precipitation ◽  
Equilibrium Phase ◽  
Quantitative Description ◽  
Present Contribution ◽  
Α Phase ◽  
The Matrix ◽  
Aging Sequence ◽  
Matrix Precipitation ◽  
Considerable Detail ◽  
Kinetics Of

It is currently well established that, for an Al-Ag alloy quenched from the α phase and aged within the metastable solvus, the aging sequence is: supersaturated α → GP zones → γ’ → γ (Ag2Al). While GP zones and plate-shaped γ’ are metastable phases, continuously distributed in the matrix, formation of the equilibrium phase γ takes place at grain boundaries by discontinuous precipitation (DP). The crystal structure of both γ’ and γ is hep with the following orientation relationship with respect to the fee α matrix: {0001}γ′,γ // {111}α, <1120>γ′,γ, // <110>α.The mechanisms and kinetics of continuous matrix precipitation (CMP) in dilute Al-Ag alloys have been studied in considerable detail. The quantitative description of DP kinetics, however, has received less attention. The present contribution reports the microstructural evolution resulting from aging an Al-Ag alloy with Ag content higher than those previously reported in the literature, focusing the observations of γ' plate-shaped metastable precipitates.

scholarly journals Continuous Cooling Transformation Behaviour and Bainite Transformation Kinetics of 23CrNi3Mo Carburised Steel

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 48
Author(s):  
Wenjun Song ◽  
Min Lei ◽  
Mingpan Wan ◽  
Chaowen Huang
Keyword(s):  
Phase Transformation ◽  
Volume Fraction ◽  
Austenite Formation ◽  
Steel Matrix ◽  
Transformation Kinetics ◽  
Bainite Transformation ◽  
Continuous Cooling ◽  
The Matrix ◽  
Dimensional Growth ◽  
Kinetics Of

In this study, the phase transformation behaviour of the carburised layer and the matrix of 23CrNi3Mo steel was comparatively investigated by constructing continuous cooling transformation (CCT) diagram, determining the volume fraction of retained austenite (RA) and plotting dilatometric curves. The results indicated that Austenite formation start temperature (Ac1) and Austenite formation finish temperature (Ac3) of the carburised layer decreased compared to the matrix, and the critical cooling rate (0.05 °C/s) of martensite transformation is significantly lower than that (0.8 °C/s) of the matrix. The main products of phase transformation in both the carburised layer and the matrix were martensite and bainite microstructures. Moreover, an increase in carbon content resulted in the formation of lamellar martensite in the carburised layer, whereas the martensite in the matrix was still lath. Furthermore, the volume fraction of RA in the carburised layer was higher than that in the matrix. Moreover, the bainite transformation kinetics of the 23CrNi3Mo steel matrix during the continuous cooling process indicated that the mian mechanism of bainite transformation of the 23CrNi3Mo steel matrix is two-dimensional growth and one-dimensional growth.

Correlations for Interaction Layer Growth in U-Mo/Al Dispersion Fuels

2017 ◽  
Vol 375 ◽  
pp. 29-39
Author(s):  
Boris A. Tarasov ◽  
Stepan N. Nikitin ◽  
Dmitry P. Shornikov ◽  
Maria S. Tarasova ◽  
Igor I. Konovalov
Keyword(s):  
Growth Rate ◽  
Growth Process ◽  
Aluminum Matrix ◽  
Layer Growth ◽  
Radiation Diffusion ◽  
Fission Rate ◽  
Interaction Layer ◽  
The Matrix ◽  
Mechanism And Kinetics ◽  
Kinetics Of

Paper presents the results of the growth rate of the interaction layer of uranium-molybdenum dispersed fuel in aluminum matrix and influence of silicon alloying on it. The growth process of amorphous interaction layer depends on the radiation diffusion which is proportional to the fission rate in the power of 1⁄4. The alloying of the matrix by silicon does not lead to a change in the mechanism and kinetics of the interaction layer growth, but only slows it down.

STUDY ON NANOMORPHOLOGY OF HIGH-STRUCTURE CARBON BLACK AND ITS BOUND RUBBER BY AFM

2012 ◽  
Vol 19 (01) ◽  
pp. 1250003
Author(s):  
JIAN CHEN ◽  
YONGZHONG JIN ◽  
JINGYU ZHANG ◽  
YAFENG WU ◽  
CHUNCAI MENG
Keyword(s):  
Carbon Black ◽  
Cluster Structure ◽  
Chemical Activity ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Atomic Force ◽  
Filled Rubber ◽  
Bound Rubber ◽  
Styrene Butadiene ◽  
High Structure

Bound rubber in carbon black (CB) filled rubber (natural rubber (NR) and styrene–butadiene rubber (SBS)) was prepared by the solvent method. The nanomorphology of CB and rubber/CB soluble rubber was observed by atomic force microscope. The results show that high-structure CB DZ13 has a "grape cluster" structure which consists of many original particles with the grain size of about 30–50 nm. Graphitizing process of CB decreases the amount of bound rubber. The NR/DZ13 soluble rubber with island–rim structure has been obtained, where the islands are DZ13 particles and the rims around the islands are occupied by NR film. But when the graphitized DZ13 particles were used as fillers of rubber, we have only observed that some graphitized DZ13 particles were deposited on the surface of the globular-like NR molecular chains, instead of the spreading of NR molecular chains along the surface of DZ13 particles, indicating that graphitized DZ13 has lower chemical activity than ungraphitized DZ13. Especially, we have already observed an interesting unusual bound rubber phenomenon, the blocked "bracelet" structure with the diameter of about 600 nm in which CB particles were blocked in ring-shaped SBS monomer.

The effect of composition and cooling rate on the structure of rapidly solidified (Fe, Ni)3Al–C alloys

1989 ◽  
Vol 4 (1) ◽  
pp. 44-49 ◽  
Author(s):  
S. A. Myers ◽  
C. C. Koch
Keyword(s):  
Cooling Rate ◽  
Base Alloy ◽  
Weight Percent ◽  
Quench Rate ◽  
Transmission Electron ◽  
Metastable Structures ◽  
Metastable Structure ◽  
The Matrix ◽  
Rapidly Solidified ◽  
Kinetics Of

There is controversy in the literature regarding the existence of the metastable γ′ phase with an ordered Ll2 structure in rapidly solidified Fe–Ni–Al–C alloys. In this study, the quench rate–metastable structure dependence was examined in the Fe–20Ni–8Al–2C (weight percent) alloy. The effect of silicon on the kinetics of phase formation was studied by adding two weight percent silicon to a base alloy of Fe–20Ni–8Al–2C. Samples were rapidly solidified in an arc hammer apparatus and examined by transmission electron microscopy. In the Fe–20Ni–8Al–2C alloy, the nonequilibrium γ′ and γ phases were found in foils 65 to 100 μm thick. At higher quench rates, i.e., thinner samples, the matrix was observed to be disordered fcc γ with K-carbide precipitates. Samples containing silicon were found to have a matrix composed of γ′ and γ structures when the foils were thicker than 40 μm. At higher quench rates, the matrix was disordered fcc γ with K-carbide precipitates. The nonequilibrium γ′ and γ structures are present in samples with or without silicon, but are observed at higher cooling rates with the addition of silicon. This sensitivity to cooling rate and composition in resulting metastable structures may explain the differences reported in the literature for these rapidly solidified materials.

Primary products and processes in the γ-radiolysis of 2-methyltetrahydrofuran

1965 ◽  
Vol 285 (1402) ◽  
pp. 319-338 ◽  
Keyword(s):  
Glassy Phase ◽  
Kcal Mole ◽  
Radical Species ◽  
Molecule Reaction ◽  
Positive Ions ◽  
Primary Products ◽  
Diffusion Controlled ◽  
Thermal Bleaching ◽  
The Matrix ◽  
Kinetics Of

From a study of the u. v., visible, near i. r. and e. s. r. spectra induced by γ -irradiation at 77°K in glassy MTHF and in glassy MTHF containing various additives and from a study of controlled temperature increases on these spectra, the following conclusions are drawn. (1) The primary products of the radiolysis are electrons ( e - ) and positive ions ( MTHF + ) which undergo a rapid ion-molecule reaction to give O CH 3 radicals ( R ⋅). (2) e - can either be trapped in the glassy MTHF matrix or can be captured by either napththalene, ferric chloride, carbon tetrachloride, nitrous oxide or trans -stilbene if these substances are present. (3) The e - T are bleachable by light or heat and disappear independently of the radicals R⋅ without either augmentation of R⋅ or the production of any new radical species. (4) e - T and R⋅ disappear thermally and independently by second-order reactions, the rate constants being K e - + e - (M -1 S -1 ) = 10 12⋅4±1⋅1 exp ─ [0⋅85 ± 0⋅10 kcal/mole/ R ( T ─ 75)] and K R˙ + R˙ (M -1 S -1 ) = 10 13⋅3±1⋅4 exp ─ [1⋅20 ± 0⋅15 kcal/mole/ R ( T ─ 75)]. These rate expressions suggest that both reactions are diffusion controlled at low temperatures in the glassy phase. (5) The kinetics of the thermal bleaching of e - T indicate that the electrons migrate distances of about 150 Å from their parent positive ions before being trapped in the matrix. (6) The effect of FeCl 3 in reducing the formation of e - T at 77°K and its lack of effect on the thermal bleaching of e - T suggests that the reaction e - + FeCl 3 → FeCl 2 + Cl - only occurs before the electron is thermalized.

Effect of Excess PbO on the Kinetics of the Growth of PMNT Polycrystals by Templated Grain Growth Method

2005 ◽  
Vol 475-479 ◽  
pp. 1137-1140
Author(s):  
Lili Zhao ◽  
Feng Gao ◽  
Wei Min Wang ◽  
Chang Sheng Tian
Keyword(s):  
Grain Growth ◽  
Templated Grain Growth ◽  
Experimental Conditions ◽  
Precipitation Mechanism ◽  
Oriented Structure ◽  
Diffusion Controlled ◽  
The Matrix ◽  
Growth Method ◽  
Final Composition ◽  
Kinetics Of

The oriented 0.67Pb (Mg1/3Nb2/3)O3-0.33PbTiO3 (PMNT) polycrystals were prepared by the conventional ceramic technique and the templated grain growth method adding excess PbO in the matrix. Kinetics of the development of oriented structure was investigated systemically. In the presence of PbO liquid phase, the oriented PMNT polycrystals mainly grow by the dissolution-precipitation mechanism. The diffusion is determined by the sintering temperature and the PbO-excess content in the matrix. The thickness of oriented PMNT polycrystals displays a t1/3 dependence, which is characteristic of diffusion-controlled growth. For the thicker oriented structure, 20% excess PbO in the PMNT matrix and 1150oC for 10h are the proper experimental conditions. Moreover, the addition of PbO in the matrix hardly affects the final composition of ceramic matrix.

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