Semiempirical Relationships between Properties and Loading in Filled Elastomers

1989 ◽  
Vol 62 (5) ◽  
pp. 788-799 ◽  
Author(s):  
A. Pouchelon ◽  
P. Vondracek
Keyword(s):  
Filler Loading ◽  
General Validity ◽  
Elongation At Break ◽  
Filled Elastomers ◽  
Polymer Filler ◽  
Adsorbed Polymer ◽  
Percolation Behavior ◽  
Filled Rubbers ◽  
Filler Network ◽  
Dynamic Storage

Abstract The dynamic storage modulus of uncured silica-filled silicone rubber increases sharply when a critical filler loading is reached. A similar behavior has been observed for the conductivity in the same compounds. The experimental data fit a percolation law fairly well, and microscopy confirms the formation of a filler network according to the percolation model. This behavior depends on a polymer-filler interaction level, suggesting a filler network consisting of filler particles bridged together by adsorbed polymer. It has been found that the percolation threshold coincides with the optimum value of elongation at break of the corresponding vulcanizates. The percolation behavior and the relations between properties of filled rubbers described here were observed in various filled rubbers of quite different compositions. This seems to suggest the general validity of the presented relationships in all elastomers reinforced by particulate fillers.

The Hysteresis Temperature and Strain Dependences in Filled Rubbers

2006 ◽  
Vol 79 (1) ◽  
pp. 170-197 ◽  
Author(s):  
Alberto Scurati ◽  
Chenchy J. Lin
Keyword(s):  
Temperature Dependence ◽  
Functional Polymers ◽  
Temperature Hysteresis ◽  
Individual Effect ◽  
Polymer Filler ◽  
Filled Rubbers ◽  
Filler Network ◽  
Dynamic Storage ◽  
Tan Δ ◽  
The Individual

Abstract The strong hysteresis (tan δ) temperature dependence observed in filled compounds containing functional polymers was investigated by studying the individual effect of filler-filler (F-F) and polymer-filler interactions (P-F). Silica filled compounds were prepared by adding n-octyl-triethoxyl or mercatopropyl-trimethoxyl silane. Both silanes are capable of retarding filler flocculation upon heating and give compounds with less developed filler networks either by reducing F-F interactions or by screening filler networks through P-F attachments. The filler network is shown to mediate the low-temperature hysteresis due to the polymer glass transition (Tg) by changing the temperature dependence of the compound dynamic storage modulus (G′). At temperatures far above the Tg, the compound tan δ is governed by mechanisms that control the degree of filler networking. Compounds with less developed networks show weaker strain dependence on G′ and tan δ. Both reduced F-F and increased P-F interactions will give a compound with a less developed network. However, significant reduced tan δ is only found in a system that shows strong P-F interaction due to less energy loss upon deformation by fewer network breakage and increased P-F crosslinks. This is exemplified by comparing the compound loss moduli (G″) of various stocks with corresponding G′ in G-plot (G″ vs. G′).

Effect of Vulcanization Temperature and Different Fillers on the Properties of Efficiently Vulcanized Natural Rubber

1979 ◽  
Vol 52 (2) ◽  
pp. 263-277 ◽  
Author(s):  
R. Mukhopadyay ◽  
S. K. De
Keyword(s):  
Particle Size ◽  
Natural Rubber ◽  
Crosslinking Density ◽  
Filler Loading ◽  
Zinc Stearate ◽  
Curing Temperature ◽  
Abnormal Behavior ◽  
Elongation At Break ◽  
Polymer Filler ◽  
Reinforcing Fillers

Abstract The present work deals with effect of vulcanization temperature on the polymer-filler interaction parameter, vulcanizate structure, and the technical properties of efficiently vulcanized natural rubber stocks in the presence of different fillers. We have used carbon blacks of four different particle sizes (ISAF, HAF, SRF, FT), reinforcing silica, and whiting. In the case of black fillers, as the particle size increases, reversion resistance increases. For all fillers, an increase of curing temperature from 150 to 180°C caused a reduction in strength, modulus, hardness, resilience; and an increase in elongation at break, compression set, and heat build-up. However, the flexing properties and abrasion loss showed improvement at higher curing temperature. Kraus' plots indicate that increase of curing temperature caused reduction in polymer-filler attachment. At both curing temperatures, the activity of fillers follow the order, ISAF > HAF > SRF > FT. Silica showed erratic behavior in that Kraus plots indicate nonreinforcement by the filler. Whiting also behaved abnormally with respect to Kraus plots; at lower filler loading, the system is nonadherent, becoming weakly adherent at higher concentrations. The abnormal behavior of silica-filled compounds has been explained on the basis of a reaction on the silica surface between silanol groups and zinc stearate. Westlinning and Wolff's αF values were found to be independent of curing temperature and characteristic of fillers only (the larger the particle size, the lower is the αF value). The increase in apparent crosslinking density in the case of reinforcing fillers is due to increased υr arising out of increased polymer-filler interaction. Therefore, the sulfur inefficiency parameters (E values) and zinc sulfide efficiency parameters (F values) become less significant in filled vulcanizates.

Anisotropic Damage Phenomena in Filled Elastomers: Experimental Observation and Constitutive Modeling

2013 ◽  
Vol 577-578 ◽  
pp. 161-164
Author(s):  
Mikhail Itskov ◽  
Roozbeh Dargazany
Keyword(s):  
Network Model ◽  
Polymer Chains ◽  
Rubber Matrix ◽  
Present Contribution ◽  
Cell Network ◽  
Filled Elastomers ◽  
Polymer Filler ◽  
Filler Network ◽  
Microscopic Damage ◽  
Filler Cell

Most important macroscopic inelastic phenomena of filled elastomers are due to microscopic damage processes inside the rubber network. For example, the Mullins effect can be explained by debonding of polymer chains from the carbon black aggregates. In turn, the damage and following recovery of aggregates are responsible for the hysteresis. All these effects also induce anisotropy of an initially isotropic material. In the present contribution, we show how these effects can be quantified experimentally and simulated by a micro-mechanical model. The model is based on the decomposition of the rubber matrix into a purely elastic polymer, a polymer-filler and a filler cell network. The polymer-filler network model takes into account the debonding of polymer chains from filler aggregates and is thus able to predict the strain induced damage and the permanent set. The filler cell network model describes breakage and recovery of filler aggregates and is responsible for the hysteresis. The presented model is in accord with a broad range of experimental observations.

Adsorption of monodisperse polybutadienes on carbon black, 1 Adsorption from dilute and semi-dilute solutions

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Kathy Vuillaume ◽  
Bassel Haidar ◽  
Alain Vidal
Keyword(s):  
Carbon Black ◽  
Polymer Chain ◽  
Anionic Polymerization ◽  
Polymer Concentration ◽  
Three Dimensional ◽  
Percolation Process ◽  
Molecular Weights ◽  
Polymer Filler ◽  
Adsorbed Polymer ◽  
Filler Network

Abstract A series of polybutadienes (PBs) of different molecular weights (in the range of 3000 to 120 000) but of identical microstructure (1,2-PB content ≈ 80%) was synthesized via anionic polymerization. The adsorption in solution of the various monodisperse PBs on carbon black (CB) was studied for different polymer/ CB ratios as well as for polymer and CB concentrations in the range of 0.1 to 100 g/l. The amount of adsorbed polymer was followed and was found to be essentially governed by the polymer concentration, which determines also the conformation of the polymer chain on the filler surface. CB concentration didn’t prove to be a pertinent parameter, whereas the polymer/filler ratio was found to control the formation of the three-dimensional polymer-filler network on the basis of a percolation process. Results are discussed with respect to the available theories.

Composites of Cysteamine Functionalised Graphene Oxide and Polypropylene

2021 ◽  
Vol 36 (3) ◽  
pp. 297-313
Author(s):  
S. S. Abbas ◽  
T. McNally
Keyword(s):  
Graphene Oxide ◽  
Crystallization Behavior ◽  
Polymer Network ◽  
Filler Loading ◽  
Elongation At Break ◽  
Polymer Filler ◽  
Reduced Graphene ◽  
Crystallisation Temperature ◽  
Covalent Bridging ◽  
Rheological Percolation

Abstract Cysteamine functionalised reduced graphene oxide (rGO) was grafted to polypropylene-graft-maleic anhydride (PP-g-MA) and subsequently melt blended with PP. The covalent bridging of rGO to PP-g-MA via the cysteamine molecule and co-crystallization are routes to promoting interfacial interactions between rGO and the PP matrix. A rheological percolation threshold was achieved for a nanofiller loading between 3 wt% and 5 wt%, but none detected for the composites prepared with un-functionalized rGO. At low loadings (0.1 wt%), functionalized rGO is well dispersed in the PP matrix, an interconnecting filler-filler, polymer-filler and polymer-polymer network is formed, resulting in increased tensile toughness (1 500%) and elongation at break (40%) relative to neat PP. Irrespective of whether the rGO was functionalised or not, it had a significant effect on the crystallization behavior of PP, inducing heterogeneous nucleation, increasing the crystallisation temperature (Tm) of PP by up to 10°C and decreasing the crystalline content (Xc) by ∼30% for the highest (5 wt%) filler loading. The growth of the monoclinic a-phase of PP is preferred on addition of functionalised rGO and b crystal growth suppressed.

On the Filler Flocculation in Silica-Filled Rubbers Part I. Quantifying and Tracking the Filler Flocculation and Polymer-Filler Interactions in the Unvulcanized Rubber Compounds

2002 ◽  
Vol 75 (5) ◽  
pp. 865-890 ◽  
Author(s):  
Chenchy J. Lin ◽  
W. L. Hergenrother ◽  
E. Alexanian ◽  
G. G. A. Böhm
Keyword(s):  
Linear Regression Analysis ◽  
Quantitative Characterization ◽  
Polymer Filler ◽  
Rubber Compounds ◽  
On Line ◽  
Filled Rubbers ◽  
Dynamic Storage ◽  
Vulcanization Process ◽  
Flocculation Process

Abstract Filler flocculation was followed for silica filled compounds containing various alkoxy silanes and non-silane type polar additives. The methodology employed in this paper permitted a quantitative characterization of filler flocculation and polymer-filler interactions after heating the compound under conditions that simulated vulcanization. With the addition of trialkoxy silanes, the reduction of filler flocculation and the degree of polymer-filler interactions were found to depend on the type and the concentration of silane added, and on the mixing drop temperature (Td) used. Greater polymer-filler interactions and flocculation suppression were obtained with a compound containing a tetrasulfane when compared to that containing either a disulfane or a monofunctional-silane. Polar additives such as an amine compound and a sugar alcohol did not reduce the silica flocculation during simulated vulcanization because they were dewetted from the silica surface upon heating. The filler flocculation process was monitored by following the change of dynamic storage moduli using an on-line rheometer. The flocculation process order and process constant were extracted from the non-linear regression analysis of the kinetic data. These kinetic parameters were used to quantify the suppression of filler flocculation by the additives used. Filler flocculation was found not to be affected by the vulcanization process because it occurred prior to the onset of cure.

Mechanical Properties and Morphologies of PP/Co-PP/Talc Composites for Microwave Application

2012 ◽  
Vol 626 ◽  
pp. 711-715 ◽  
Author(s):  
J. Piwsawang ◽  
T. Jinkarn ◽  
Chiravoot Pechyen
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Filler Loading ◽  
Lower Yield ◽  
Elongation At Break ◽  
Compression Load ◽  
Microwave Application ◽  
Lower Yield Strength ◽  
Morphology Development ◽  
Internal Mixer

Unmodified talc fillers were compounded with polypropylene (PP) and copolymer polyethylene (Co-PP) separately in a Brabender plasticorder internal mixer at 180 °C and 50 rpm in order to obtain composites, which contain 040 phr (per 100 part of resin) of filler at 40 phr intervals. The morphology development and the mechanical properties of the composites with reference to filler loading were investigated. In terms of mechanical properties, Youngs modulus and maximum compression load increased, whereas yield strength and elongation at break decreased with the increase in filler loading of PP/Co-PP/Talc composites. The PP/Co-PP exhibited lower yield strength and youngs modulus, and higher elongation at break than talc composites (data not show here). Scanning electron microscopy (SEM) was used to examine the structure of the fracture surface to justify the variation of the measured mechanical properties.

Influence of Novel Electron Beam Modified Surface Treated Dual Phase Filler on Rheometric and Mechanical Properties of Styrene Butadiene Rubber Vulcanizates

2003 ◽  
Vol 76 (2) ◽  
pp. 299-317 ◽  
Author(s):  
A. M. Shanmugharaj ◽  
Anil K. Bhowmick
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Beam ◽  
Styrene Butadiene Rubber ◽  
Dual Phase ◽  
Butadiene Rubber ◽  
Elongation At Break ◽  
Polymer Filler ◽  
Modified Surface ◽  
Styrene Butadiene

Abstract Rheometric and mechanical properties, hysteresis and swelling behavior of the Styrene-Butadiene Rubber vulcanizates (SBR) filled with unmodified and novel electron beam modified surface treated dual phase fillers were investigated. Scorch time increases for these modified filler loaded vulcanizates due to introduction of quinone type oxygen on the surface. Electron beam modification of dual phase filler in the absence of trimethylol propanetriacrylate (TMPTA) or triethoxysilylpropyltetrasulphide (Si-69) significantly improves the modulus of the SBR vulcanizates, whereas the values of tensile strength and elongation at break drop. However, presence of TMPTA or silane slightly increases the modulus with significant improvement in tensile strength. This effect is more pronounced at higher loading of these modified fillers in SBR vulcanizates. These variations in modulus and tensile strength are explained by the equilibrium swelling data, Kraus plot and a new mathematical model interpreting the polymer-filler interaction. Hysteresis loss ratio of SBR vulcanizates loaded with irradiated fillers in absence and presence of TMPTA or silane increases due to highly aggregated structure of the filler.

Memory of Prior Dynamic Strain History in Filled Rubbers

2010 ◽  
Vol 83 (2) ◽  
pp. 149-159 ◽  
Author(s):  
Xiaorong Wang ◽  
Christopher G. Robertson
Keyword(s):  
Small Strain ◽  
Dynamic Strain ◽  
Hole Burning ◽  
Strain History ◽  
Power Relationship ◽  
Filled Elastomers ◽  
Dynamic Spectra ◽  
Filled Rubbers ◽  
Spectrum Hole ◽  
Relationship Of

Abstract We recently discovered that particle-reinforced rubbers after being sheared (or aged) in oscillation at a frequency ƒa at a small strain γa (e.g., ∼1% strain) for time ta can often display a spectrum hole or drop in their dissipation spectra. The location of the hole depends on the aging strain amplitude γa. The depth of this hole is influenced by both the oscillatory aging frequency ƒa and the aging duration ta, and follows a simple power relationship of the product of ƒa and ta. Sequential shear at two strains reveals that when γa1>γa2 the resulting dynamic spectra appear to be a combination of that aged at γa1 and γa2, whereas for γa1>γa2, the resulting dynamic spectra only reflect the characteristic hole burning of the second strain after holding at γa2. This new memory effect occurs at very small strains in filled elastomers and involves material stiffening during the strain aging; both of those features are quite different from the Mullins effect. Also, this new memory is found to last for more than 10 days without any noticeable sign of disappearing.

Filler Network Change and Nonlinear Viscoelasticity of Rubbers

2006 ◽  
Vol 11-12 ◽  
pp. 729-732 ◽  
Author(s):  
Yoshinobu Isono ◽  
Y. Satoh ◽  
Shuji Fujii ◽  
Seiichi Kawahara ◽  
S. Kagami
Keyword(s):  
Electrical Resistivity ◽  
Dynamic Modulus ◽  
Network Formation ◽  
Nonlinear Viscoelasticity ◽  
Large Strain ◽  
Relaxation Modulus ◽  
Network Structures ◽  
Wide Range ◽  
Filled Rubbers ◽  
Filler Network

Uncured, filled rubbers show remarkable nonlinear viscoelasticity as well as cured, filled rubbers. The nonlinearity may come from change in entanglement and filler network structures. Many people use dynamic modulus to characterize rubber materials. However, dynamic modulus cannot be defined at large strain. Hence we must study a viscoelastic function to be defined at large strain. In addition, we need other information to separate the effects of the change in entanglement and filler network structures on nonlinear viscoelasticity. In this work, we have measured simultaneously relaxation modulus G(γ,t) and electrical resistivity ρ(γ,t) for carbon black (CB)-filled, uncured styrene-butadiene copolymers (SBRs) at wide range of strains. Electrical resistivity at equilibrium, ρ(0,t), showed step-like change at the CB loading between 20 and 35 phr, indicating threshold for filler network formation should exist in the range of values in CB loading. Both G(γ,t) and ρ(γ,t) for the samples having CB loading to be higher than the threshold showed nonlinearity at the strain larger than shear strain γ=0.1, indicating rupture in filler network at large strain.

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