Hysteresis Contributions in Carbon Black-Filled Rubbers Containing Conventional and Tin End-Modified Polymers

1998 ◽  
Vol 71 (4) ◽  
pp. 637-667 ◽  
Author(s):  
J. D. Ulmer ◽  
W. L. Hergenrother ◽  
D. F. Lawson
Keyword(s):  
Carbon Black ◽  
Loss Modulus ◽  
Average Molecular Weight ◽  
Polymer Network ◽  
Linear Polymers ◽  
Network Chain ◽  
Modified Polymers ◽  
Rubber Compounds ◽  
Effective Network ◽  
Tan Δ

Abstract A methodology was developed to estimate individual hysteresis contributions arising from the carbon black network, polymer free chain ends and effective polymer network chains. The estimation technique was applied to rubber compounds formulated with linear polymers of varied number-average molecular weight (Mn) from each of three different series. The three series corresponded to polymers modified with either zero, one or two tin ends per chain. In general, the relative hysteresis contributions depend on strain amplitude and Mn. For unmodified polymers at strain amplitudes from 0.02 to 0.07, and with Mn in the neighborhood of 150 kg/mole, each of the three hysteresis sources contributes about one-third of the total tan δ. With respect to shear loss modulus (G″), the carbon black network contributes about 60%, while free chain ends and the effective polymer network chains each contribute about 20%. At the same Mn and strain conditions, tin end-modified polymers reduce G″ and tan δ by as much as 60%, in comparison to their unmodified counterparts. The benefit is achieved primarily through reductions of up to 85% in the carbon black network contribution to hysteresis. Since the hysteresis contribution from free chain ends is not reduced so much by tin end-modification, the greatest potential for additional tan δ benefits lies in further free chain end reduction. In addition, it was found that tin end-modification has no measurable effect on the hysteresis contribution from effective network chains. Further, the analysis showed that an ineffective polymer network chain provides approximately ten times the hysteresis and one-half the elasticity of an effective network chain, at the test conditions of the current study. In general, the quantitative results, and some qualitative results as well, will change with compound composition and with temperature. Consequently, the development of a methodology, one that allows estimation of individual hysteresis contributions from different sources, is a major component of the present study.

Assignment of Effective Network Chains in Cured Rubbers Derived from Chemical Crosslinking, Entanglements, Polymer End Linking to Carbon Black and Filler Interaction: VII. Tensile Retraction Measurements

2006 ◽  
Vol 79 (2) ◽  
pp. 338-365
Author(s):  
William L. Hergenrother ◽  
J. D. Ulmer ◽  
Christopher G. Robertson
Keyword(s):  
Carbon Black ◽  
Volume Fraction ◽  
Polymer Network ◽  
Polymer Chains ◽  
Network Chain ◽  
End Groups ◽  
Individual Contributions ◽  
Cross Links ◽  
Effective Network ◽  
The Individual

Abstract The individual contributions to effective network chains from chemical cross-links and from trapped polymer chain entanglements were estimated for gum rubber compounds using Tensile Retraction (TR). In addition, the influences of carbon black and of polymers with functional end-groups, on the character of the polymer network in filled compounds were explored. The effective network chain contributions were established for gum vulcanizates through an entanglement model and an independent estimate of the polymer molecular weight between entanglements, Me. It was found that Me was related closely to the extrapolated γ intercepts obtained from the TR of cured gums. The gum compounds were used to further estimate the effects of fillers and functional end-groups on the total number of effective network chains. Comparing an α,ω-difunctional SBR with its non-functional counterpart enabled the assessment of the effects of functional end-groups. The comparison allowed for the determination of the probability, π, that a functional end group reacts with carbon black. The π was seen to increase as the volume fraction of filler increased, and π2 provided an estimate of the fraction of functional polymer chains that react with carbon black at both ends.

scholarly journals Use of waste materials in rubber matrix

2018 ◽  
Vol 157 ◽  
pp. 07009 ◽  
Author(s):  
Mariana Pajtášová ◽  
Zuzana Mičicová ◽  
Darina Ondrušová ◽  
Slavomíra Božeková ◽  
Róbert Janík ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Loss Modulus ◽  
Rolling Resistance ◽  
Dynamic Mechanical Properties ◽  
Waste Materials ◽  
Partial Replacement ◽  
Rubber Matrix ◽  
Loss Angle ◽  
Rubber Compounds ◽  
Tan Δ

The presented paper deals with the use of waste materials as ecological fillers into rubber matrix. Waste materials were used as partial replacement of the commercial filler – carbon black, designated as N339. These prepared rubber compounds were characterized on the basis of the rheology and vulcanization characteristics – minimum torque (ML), maximum torque (MH), optimum time of vulcanization (t(c90)), processing safety of compound (ts), rate coefficient of vulcanization (Rv). In the case of the prepared vulcanizates, physical-mechanical properties (tensile strength, tensibility and hardness) and dynamic-mechanical properties (storage modulus, loss modulus, loss angle tan δ) were investigated. Using the dependency of loss angle on temperature, the selected properties for tyre tread vulcanizates were evaluated, including traction on snow and ice, traction on the wet surface and rolling resistance.

Dynamic Mechanical Properties of NR-HDPE Blends

1987 ◽  
Vol 60 (4) ◽  
pp. 591-599 ◽  
Author(s):  
S. Akhtar ◽  
S. S. Bhagawan
Keyword(s):  
Mechanical Properties ◽  
Carbon Black ◽  
Storage Modulus ◽  
Loss Tangent ◽  
Loss Modulus ◽  
Dynamic Mechanical Properties ◽  
Thermoplastic Elastomers ◽  
Dynamic Mechanical ◽  
Storage And Loss Moduli ◽  
Tan Δ

Abstract Dynamic mechanical properties such as storage modulus, loss modulus, and loss tangent have been evaluated over a wide range of temperatures for thermoplastic elastomers prepared from blends of NR and HDPE. It was observed that above room temperature, both storage and loss moduli increased and loss tangent decreased as the HDPE content in the blend increased. The effects of dynamic crosslinking and carbon black filler on dynamic mechanical behavior of 70/30 NR/HDPE blend were also examined. Carbon black increased the storage and loss moduli but lowered and broadened the tan δ peak. On the other hand, crosslinking increased storage modulus and decreased the loss modulus and loss tangent, particularly after the NR Tg. The tan δ peak area which appeared at Tg for NR was proportional to the rubber content in the blends.

Dynamic Mechanical Analysis of Carbon-Black-Filled Rubber Vulcanizates under Swollen Conditions

1990 ◽  
Vol 63 (5) ◽  
pp. 651-659 ◽  
Author(s):  
Chanchal Neogi ◽  
A. K. Bhattacharya ◽  
Anil K. Bhowmick ◽  
S. P. Basu
Keyword(s):  
Carbon Black ◽  
Surface Area ◽  
Storage Modulus ◽  
Loss Modulus ◽  
Mechanical Analysis ◽  
Rubber Matrix ◽  
Filled Rubber ◽  
Tan Δ ◽  
Swollen Vulcanizates ◽  
Limiting Value

Abstract 1. For unswollen vulcanizates, storage modulus (E′) decreases with the increase in temperature and decrease in loading and surface area of carbon-black filler. On partial swelling, these effects are much reduced, and E′ becomes independent of surface area and loading on equilibrium swelling. 2. Loss modulus (E″) of unswollen vulcanizates also follows the same trend. However, on swelling in xylene, E″ increases to a great extent because of contributions from both the solvent and the rubber matrix. 3. Loss tangent (tan δ) also decreases with increase in temperature and decrease in loading of carbon black. On swelling, it optimizes at 30 phr loading. 4. Tan δ increases with ϕΨ for unswollen samples, but swollen vulcanizates show an optimum in tan δ at ϕΨ=2.5. 5. Limiting value of storage modulus has been determined for all the filled samples.

VULCANIZATE STRUCTURES AND MECHANICAL PROPERTIES OF RUBBER COMPOUNDS WITH SILICA AND CARBON BLACK BINARY FILLER SYSTEMS

2020 ◽  
pp. 000-000 ◽  
Author(s):  
Il Jin Kim ◽  
Byungkyu Ahn ◽  
Donghyuk Kim ◽  
Hyung Jae Lee ◽  
Hak Joo Kim ◽  
...  
Keyword(s):  
Carbon Black ◽  
Physical Properties ◽  
Crosslink Density ◽  
Crosslinking Density ◽  
Silica Content ◽  
Rubber Matrix ◽  
Rubber Compounds ◽  
High Elongation ◽  
Chemical Crosslinks ◽  
Tan Δ

ABSTRACT The physical properties of rubber compounds are mainly determined by the filler dispersion within the rubber matrix, filler–rubber interaction, and chemical crosslink structure caused by sulfur. Carbon black or silica is typically used as a reinforcing filler in tire tread compounds; however, binary filler systems comprising the two types of filler are also currently being used to complement each other. This study used binary filler systems to manufacture vulcanizates and classified the vulcanizate structures as chemical crosslinks caused by sulfur, physical crosslinks caused by carbon black (carbon black–bound rubber), and silica–silane–rubber networks caused by silica and silane. The effect of each vulcanizate structure on the physical properties was also calculated. In the proposed binary filler system, silica chemically bonds with rubber molecules, unlike carbon black. Therefore, the crosslink density per unit of silica content was 19% higher than that of carbon black, in which rubber molecules were physically adsorbed on the surface. Tensile properties affected by 1 unit of crosslinking density for each filler were calculated, and silica was found to contribute more in the low-elongation range, whereas carbon black contributed more in the high-elongation range. Regarding tan δ at 60 °C and abrasion resistance per unit crosslink density of filler, carbon black made a greater contribution than silica, whereas silica had a greater contribution to wet traction and snow traction.

Damping Characteristics of Polyurethane-Based Simultaneous Interpenetrating Polymer Networks

1996 ◽  
Vol 8 (1) ◽  
pp. 19-34 ◽  
Author(s):  
Douglas J Hourston ◽  
Franz-Ulrich Schäfer
Keyword(s):  
Loss Modulus ◽  
Polymer Network ◽  
Polymer Networks ◽  
Interpenetrating Polymer Networks ◽  
Interpenetrating Polymer Network ◽  
Damping Characteristics ◽  
Linear Rule ◽  
High Transition ◽  
Tan Δ ◽  
Energy Absorbing

A brief overview of damping with polymers is given. The highest energy absorbing potential of polymers is centred around their glass transition temperature ( T g). In order to broaden the transition, partially miscible polymer pairs with fairly widely separated T gs can be used to give broad and high transition regions. This can be obtained by the use of interpenetrating polymer network (IPN) technology. The damping ability of the IPNs was assessed from the tan δ and loss modulus versus temperature curves. The area under the linear tan δ curve (TA) and the loss modulus equivalent (LA) were calculated and correlated with the IPN composition. An incompatible polyurethane/polystyrene IPN was chemically modified by internetwork grafting and the use of compatibilizers, resulting in a high and broad transition with tan δ values > 0.3 over 80°C and 135°C respectively. Conducting a stirred polymerization of a 60:40 PUR/PS IPN resulted in a very complicated morphology with phases within phases within phases, Values for tan δ were greater than 0.3 from −19°C to 145°C combined with a high TA area of 85.4 K. The influence of the composition on the damping ability was studied in a semicompatible polyurethane/polyethyl methacrylate IPN. At the 70:30 composition, a broad temperature range (> 130°C) of tan δ values greater than 0.3 and a high TA area of 62.1 K resulted. LA was found to increase with increasing PEMA content, but with values well below those expected from applying the linear rule of mixing to LA of the homonetworks. TEM micrographs further elucidated the multiphase morphologies.

Partial replacement of carbon black by nanoclay in butyl rubber compounds for tubeless tires

2017 ◽  
Vol 59 (11-12) ◽  
pp. 1054-1060 ◽  
Author(s):  
Mohan Kumar Harikrishna Kumar ◽  
Subramaniam Shankar ◽  
Rathanasamy Rajasekar ◽  
Pal Samir Kumar ◽  
Palaniappan Sathish Kumar
Keyword(s):  
Carbon Black ◽  
Butyl Rubber ◽  
Partial Replacement ◽  
Rubber Compounds

scholarly journals Effect of Nanofiller Content on Dynamic Mechanical and Thermal Properties of Multi-Walled Carbon Nanotube and Montmorillonite Nanoclay Filler Hybrid Shape Memory Epoxy Composites

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 700
Author(s):  
Muhamad Hasfanizam Mat Yazik ◽  
Mohamed Thariq Hameed Sultan ◽  
Mohammad Jawaid ◽  
Abd Rahim Abu Talib ◽  
Norkhairunnisa Mazlan ◽  
...  
Keyword(s):  
Shape Memory ◽  
High Performance ◽  
Loss Modulus ◽  
Decomposition Temperature ◽  
Hybrid Nanocomposites ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry ◽  
Hybrid Filler ◽  
Dynamic Mechanical ◽  
Tan Δ

The aim of the present study has been to evaluate the effect of hybridization of montmorillonite (MMT) and multi-walled carbon nanotubes (MWCNT) on the thermal and viscoelastic properties of shape memory epoxy polymer (SMEP) nanocomposites. In this study, ultra-sonication was utilized to disperse 1%, 3%, and 5% MMT in combination with 0.5%, 1%, and 1.5% MWCNT into the epoxy system. The fabricated SMEP hybrid nanocomposites were characterized via differential scanning calorimetry, dynamic mechanical analysis, and thermogravimetric analysis. The storage modulus (E’), loss modulus (E”), tan δ, decomposition temperature, and decomposition rate, varied upon the addition of the fillers. Tan δ indicated a reduction of glass transition temperature (Tg) for all the hybrid SMEP nanocomposites. 3% MMT/1% MWCNT displayed best overall performance compared to other hybrid filler concentrations and indicated a better mechanical property compared to neat SMEP. These findings open a way to develop novel high-performance composites for various potential applications, such as morphing structures and actuators, as well as biomedical devices.

Electrical conductivity and rheological properties of carbon black based conductive polymer composites prior to and after annealing

2021 ◽  
pp. 096739112110012
Author(s):  
Qingsen Gao ◽  
Jingguang Liu ◽  
Xianhu Liu
Keyword(s):  
Electrical Conductivity ◽  
Carbon Black ◽  
Percolation Threshold ◽  
Rheological Properties ◽  
Network Formation ◽  
Loss Modulus ◽  
Conductive Polymer ◽  
Complex Viscosity ◽  
Electrical Percolation ◽  
Electrical Percolation Threshold

The effect of annealing on the electrical and rheological properties of polymer (poly (methyl methacrylate) (PMMA) and polystyrene (PS)) composites filled with carbon black (CB) was investigated. For a composite with CB content near the electrical percolation threshold, the formation of conductive pathways during annealing has a significant impact on electrical conductivity, complex viscosity, storage modulus and loss modulus. For the annealed samples, a reduction in the electrical and rheological percolation threshold was observed. Moreover, a simple model is proposed to explain these behaviors. This finding emphasizes the differences in network formation with respect to electrical or rheological properties as both properties belong to different physical origins.

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