Hysteresis temperature dependence in filled rubbers. II. Mechanical mixing, filler microdispersion, and polymer–filler interactions

2008 ◽  
Vol 108 (3) ◽  
pp. 1722-1736 ◽  
Author(s):  
Alberto Scurati ◽  
William L. Hergenrother ◽  
Chenchy J. Lin
Keyword(s):  
Temperature Dependence ◽  
Mechanical Mixing ◽  
Polymer Filler ◽  
Filled Rubbers

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′).

On the Filler Flocculation in Silica and Carbon Black Filled Rubbers: Part II. Filler Flocculation and Polymer-Filler Interaction

2004 ◽  
Vol 77 (1) ◽  
pp. 90-114 ◽  
Author(s):  
Chenchy J. Lin ◽  
Terrence E. Hogan ◽  
William L. Hergenrother
Keyword(s):  
Carbon Black ◽  
Temperature Dependence ◽  
Thermal Annealing ◽  
Elevated Temperatures ◽  
Strong Dependence ◽  
Rolling Resistance ◽  
Tetraethyl Orthosilicate ◽  
Polymer Filler ◽  
End Groups ◽  
Filled Rubbers

Abstract Filler flocculation and polymer-filler interaction in silica and carbon black filled rubbers containing different functional end-groups were investigated. Lithium-hexamethyleneimine initiated polymers terminated with a proton (HMI-P-H), SnCl4 (HMI-P-Sn), and a mixture of SnCl4 and tetraethyl orthosilicate (HMI-P-TEOS) were employed to determine the affinities of various functionalities toward fillers. Reduced filler flocculation was found for compounds of HMI-P-Sn and HMI-P-TEOS after thermal annealing at 171 °C for 15 minutes when compared to the annealed HMI-P-H stock. Curing at the same condition used for annealing gave further suppression of filler flocculation for HMI-P-TEOS stock by increased polymer-filler interaction during cure. Polymer-filler interaction was followed by examining G′ strain dependence and the differences in G′ obtained between HMI-P-Sn or HMI-P-TEOS and HMI-P-H (δG′). This treatment gave a peak maximum in the δG′ plot as a function of strain. The magnitude of the maximum in HMI-P-TEOS stock is double that of HMI-P-Sn stock and increased after thermal annealing. The compound tanδ temperature dependence showed higher hysteresis around the Tg transition and strong dependence at elevated temperatures was found for HMI-P-TEOS stocks. This increased polymer-filler interaction is manifested with increased 0 °C tanδ and reduced 50 °C tanδ which relates to the improved wet traction and rolling resistance for tires.

Mooney Viscosity Stability and Polymer Filler Interactions in Silica Filled Rubbers

2002 ◽  
Vol 75 (2) ◽  
pp. 215-245 ◽  
Author(s):  
Chenchy Lin ◽  
William L. Hergenrother ◽  
Ashley S. Hilton
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Ester ◽  
Hydrolytic Stability ◽  
Unsaturated Rubber ◽  
Polymer Filler ◽  
Rubber Compounds ◽  
Filled Rubbers ◽  
Mooney Viscosity ◽  
Sugar Fatty Acid Ester ◽  
Viscosity Stability

Abstract The change in Mooney viscosity (ML1+4) with aging was followed for silica filled compounds containing various silanes and polar additives. Several mechanisms for the aging stability are postulated and evaluated through experimentation. The type of silane or polar additive used can cause the ML1+4 to increase or even decrease during aging. When bis(triethoxy silanes) are used in silica filled rubbers, the ML1+4 growth during aging is caused by hydrolysis. Silica-silica bridging was found to be responsible for the ML1+4 growth in rubber compounds containing a more thermally stable polysulfide or a sulfur-free bis(triethoxy silane). When the bis(triethoxy silane) is bis(3-triethoxysilylpropyl) tetrasulfide (TESPT), a fraction of TESPT is attached to the unsaturated rubber to give polymer-silica attachments. These attachments further enhance the hydrolytic ML1+4 increase during aging. Chemical coating of the silica with a monofunctional silane or a physical coating with a trialkyl amine compound effectively stops the ML1+4 increase upon aging. The prevention of ML1+4 growth is so efficient that a reduction in the ML1+4 can be realized by absorption of ambient moisture. The extent of ML1+4 reduction caused by moisture depends on the degree of hydrophobation of the coated silicas. Hydrolytic stability was also studied with an amine or a sugar fatty acid ester that formed either strong or weak polar associations to the silica.

scholarly journals Filler Effects on Temperature Dependence of Viscoelastic Properties of Filled Rubbers

2007 ◽  
Vol 3 ◽  
pp. 41-48 ◽  
Author(s):  
Junhao Wu ◽  
Shuji Fujii ◽  
Seiichi Kawahara ◽  
Yoshinobu Isono
Keyword(s):  
Temperature Dependence ◽  
Viscoelastic Properties ◽  
Filled Rubbers

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.

Relation between Abrasion and Strength of Rubber

1966 ◽  
Vol 39 (2) ◽  
pp. 287-305 ◽  
Author(s):  
K. A. Grosch ◽  
A. Schallamach
Keyword(s):  
Energy Density ◽  
Temperature Dependence ◽  
Effective Rate ◽  
Tensile Failure ◽  
High Rate ◽  
Sliding Velocity ◽  
Proportionality Constant ◽  
Filled Rubbers ◽  
Effects Of Temperature ◽  
Frictional Energy Dissipation

Abstract The temperature dependence of abrasion of various gum and black-filled rubbers on silicon carbide paper is closely similar to the temperature dependence of their energy density at break determined at a high rate of extension. The conclusion is drawn that this type of abrasion is predominantly due to tensile failure, as had been envisaged in earlier work. The effective rate of extension during abrasion at a sliding velocity of 1 cm/sec is about 10,000 per cent/sec. The volume of abraded rubber is approximately proportional to the ratio between frictional energy dissipation and energy density at break. The proportionality constant is greater for black-filled than for gum rubbers. The effects of temperature and velocity on the abrasion of non-crystallizing gums are interrelated by means of the Ferry transform, indicating the viscoelastic nature of the abrasion process operating on these compounds.

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.

scholarly journals An understandable approach to the temperature dependence of electric properties of polymer-filler composites using elementary quantum mechanics

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Masaru Matsuo ◽  
Rong Zhang ◽  
Yuezhen Bin
Keyword(s):  
Electron Transfer ◽  
Quantum Mechanics ◽  
Temperature Dependence ◽  
Low Voltage ◽  
Joule Heat ◽  
Electric Properties ◽  
Tunnel Current ◽  
Flexible Polymer ◽  
Polymer Filler ◽  
Floor Heating

Abstract In today’s society, with a high percentage of elderly people, floor heating to ensure constant temperature and heat jackets in winter play important roles in winter to them to live comfortable lives without compromising health – except tropical zones. Under floor heating maintains a comfortable temperature in a room without polluting the air and heat jackets allow for light clothing at comfortable temperatures. The two facilities are attributed to Joule heat generated by tunnel currents between adjacent short carbon fillers in flexible polymer matrixes under low voltage. The current between adjacent conductive fillers is due to electron transfer associated with elementary quantum mechanics. Most of undergraduate students investigating polymer physics will have learned, about electron transfer in relation to the temperature dependence of the conductivity of conductive filler-insulator polymer composites as well as the phenomenon of Joule heat at high school. Despite their industrial importance, most students show little interest for investigating electric properties, since most of polymers are insulation materials. Polymer scientists have carried out qualitative analyses for tunneling current using well-known simplified equations derived from complicated mathematical process formulated by solid-state physicists. Hence this paper is focused on a teaching approach for temperature dependence on electric properties of the polymer-filler composites relating to tunnel current in terms of elementary quantum mechanics. The approach also attempts to bridge education and research by including reference to the application limit of the well-known theories to such complicated composite systems that fillers are dispersed uniformly in the polymer matrix.

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