Self-Diffusion Coefficients and Tack of Some Rubbery Polymers

1966 ◽  
Vol 39 (2) ◽  
pp. 217-225 ◽  
Author(s):  
John D. Skewis
Keyword(s):  
Diffusion Coefficients ◽  
Close Contact ◽  
Polymer Chains ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Microscopic Scale ◽  
Self Diffusion ◽  
Molecular Weights ◽  
Diffusion Rates ◽  
Styrene Butadiene

Abstract Self-diffusion coefficients for natural rubber, styrene butadiene rubber, ethylene propylene rubber and butyl rubber, are reported. Rates were determined by application of a layer of radioactively labeled polymer to the top of an unlabeled polymer base film and following the decay of radioactivity at the surface of the system, which decreased as a result of self-absorption. Macroscopically, diffusion is very slow, in fact difficult to measure, but on a microscopic scale it is rapid enough to cause considerable intermingling of polymer chains across an interface within a few seconds after two layers of polymeric material are brought into close contact. However, there were no major differences of self-diffusion coefficients between several types of polymers of comparable molecular weights. Therefore, the magnitudes of the coefficients suggest that diffusion may well be an important step for development of tacky adhesion, but the results also suggest that variations in observed tackiness among polymers cannot be simply ascribed to variations in diffusion rates.

scholarly journals Analysis of the Impact on the Mechanical Properties of Modification of Oligohydroxyethers in Organic Solvent Solution with Rubbers

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 519
Author(s):  
Vitalii Bezgin ◽  
Agata Dudek ◽  
Adam Gnatowski
Keyword(s):  
Mechanical Properties ◽  
Scientific Paper ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Molecular Weights ◽  
Wide Range ◽  
Strength Tests ◽  
Materials Used ◽  
Styrene Butadiene ◽  
The Impact

This paper proposes and presents the chemical modification of linear hydroxyethers (LHE) with different molecular weights (380, 640, and 1830 g/mol) with the addition of three types of rubbers (polysulfide rubber (PSR), polychloroprene rubber (PCR), and styrene-butadiene rubber (SBR)). The main purpose of choosing this type of modification and the materials used was the possibility to use it in industrial settings. The modification process was conducted for a very wide range of modifier additions (rubber) per 100 g LHE. The materials obtained in the study were subjected to strength tests in order to determine the effect of the modification on functional properties. Mechanical properties of the modified materials were improved after the application of the modifier (rubber) to polyhydroxyether (up to certain modifier content). The most favorable changes in the tested materials were registered in the modification of LHE-1830 with PSR. In the case of LHE-380 and LHE-640 modified in cyclohexanol (CH) and chloroform (CF) solutions, an increase in the values of the tested properties was also obtained, but to a lesser extent than for LHE-1830. The largest changes were registered for LHE-1830 with PSR in CH solution: from 12.1 to 15.3 MPa for compressive strength tests, from 0.8 to 1.5 MPa for tensile testing, from 0.8 to 14.7 MPa for shear strength, and from 1% to 6.5% for the maximum elongation. The analysis of the available literature showed that the modification proposed by the authors has not yet been presented in any previous scientific paper.

Measurement and correlation of mutual diffusion coefficients for styrene-butadiene rubber(SBR)-n-nonane systems

1993 ◽  
Vol 33 (6) ◽  
pp. 322-327 ◽  
Author(s):  
Yoshio Iwai ◽  
Shinji Miyamoto ◽  
Hideaki Ikeda ◽  
Yasuhiko Arai ◽  
Shigetoshi Kobuchi ◽  
...  
Keyword(s):  
Diffusion Coefficients ◽  
Mutual Diffusion ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Styrene Butadiene

Bonding of Ultra High Molecular Weight Polyethylene to Styrene-Butadiene Rubber

1993 ◽  
Vol 66 (1) ◽  
pp. 92-97 ◽  
Author(s):  
Gary R. Hamed ◽  
Hasan S. Dweik
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Average Molecular Weight ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Molecular Weights ◽  
Order Of Magnitude ◽  
High Bond ◽  
Styrene Butadiene ◽  
Ultra High Molecular Weight

Abstract The adhesion between a sulfur-vulcanized SBR and polyethylenes (PE) of various molecular weights has been determined using a T-peel geometry. When the viscosity average molecular weight of the polyethylene exceeds about 700 k, bonding is sufficient to cause rubber tear during peeling. In contrast, with PE of Mv≈147k, joint strength is reduced by more than an order of magnitude and fracture proceeds between the SBR and PE. It is hypothesized that the high bond strength with the ultra high molecular weight polyethylene (UHMWPE) is due to the formation of entrapped tangles between chains of the two adherends. Consistent with this, SBR-UHMWPE bonds are not disrupted after extensive swelling in toluene.

Molecular Weight Control of Elastomers Prepared by Emulsion Polymerization

1976 ◽  
Vol 49 (3) ◽  
pp. 610-649 ◽  
Author(s):  
C. A. Uraneck
Keyword(s):  
Molecular Weight ◽  
Emulsion Polymerization ◽  
Weight Control ◽  
Experimental Studies ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Molecular Weights ◽  
Emulsion Systems ◽  
Commercial Polymers ◽  
Styrene Butadiene

Abstract Control of molecular weight is a prerequisite for the production of commercial polymers. This is especially true of elastomers for which satisfactory processing is either an implied or a formal specification. This review covers the theories and their applications for the control of molecular weights for the production of styrene-butadiene rubber (SBR), emulsion butadiene rubber (E-BR), nitrile-butadiene rubber (NBR), chloroprene rubber (CR), acrylic-butadiene rubber (ABR), and acrylic rubber. The complexity of the emulsion polymerization system is reflected in the large number of experimental and theoretical studies. Chronologically the theories and experiments based on the original mechanism proposed by Harkins and on the quantitative hypothesis of Smith and Ewart evolved into numerous publications. These works have been periodically reviewed, and several recent reviews give detailed descriptions of these studies. A review by Alexander and Napper, although subjective in choice of papers examined, presents a critical analysis of the major theories of emulsion polymerization systems. However, none of the reviews just cited cover in a significant way the control of the molecular weight of polymers prepared in the presence of reactive transfer agents. The theoretical and experimental studies of the control of molecular weight of elastomers prepared in emulsion systems came from a series of studies different from those concerned solely with emulsion theory and mechanism. In this review the broad features of the mechanism first proposed by Harkins and the hypothesis of Smith and Ewart are accepted. The derivation of modifier depletion and molecular weight equations and the calculation of the theoretical curves used in emulsion systems for the preparation of elastomers are presented next.

Improvement of mechanical performance of solution styrene butadiene rubber by controlling the concentration and the size of in situ derived sol–gel silica particles

RSC Advances ◽  
2016 ◽  
Vol 6 (40) ◽  
pp. 33643-33655 ◽  
Author(s):  
V. Sankar Raman ◽  
A. Das ◽  
K. W. Stöckelhuber ◽  
S. B. Eshwaran ◽  
J. Chanda ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Sol Gel ◽  
Silica Particles ◽  
Polymer Chains ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Styrene Butadiene ◽  
Elastomeric Composites ◽  
Alkoxide Route

The silica particles generated from alkoxide route are grown onto the styrene butadiene polymer chains and offer a direct rubber to filler interaction. As a result, superior mechanical performance of the elastomeric composites can be realised.

scholarly journals Analysis of Mechanical Performance of Bitumen Modified with Waste Plastic and Rubber Additives by Rheology and Self Diffusion NMR Experiments

2019 ◽  
Vol 21 (3) ◽  
pp. 235 ◽  
Author(s):  
P. Caputo ◽  
M. Porto ◽  
V. Loise ◽  
B. Teltayev ◽  
C. Oliviero Rossi
Keyword(s):  
Mechanical Performance ◽  
Spin Echo ◽  
Chemical Properties ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Modified Bitumen ◽  
Waste Plastic ◽  
Self Diffusion ◽  
Physico Chemical ◽  
Styrene Butadiene

In this study, the mechanical and physico-chemical properties of a new kind of modified bitumen are presented. The bituminous binders have been modified in order to understand the effect on the structural properties of several compounds such as a Polymer elastomer as Styrene Butadiene Rubber (SBR), Polymer thermoplastic polypropylene (PP) and a waste plastic (Waste PP). Laboratory tests have been focused on the characterization of bitumen modified with single product and their binary combinations compared with pristine binder as a reference. Characterization has been conducted by using conventional as well as advanced methods on bitumens. Fundamental rheological tests, based on dynamic shear rheometer in the temperature range from -30 °C to +160 °C have been performed and the structure of a bitumens and modified bitumens has been analysed by the mobility of the oily maltene by self-diffusion Pulsed field gradient spin-echo (PGSE) FT-NMR experiments.

scholarly journals FLOCCULATION, REINFORCEMENT, AND GLASS TRANSITION EFFECTS IN SILICA-FILLED STYRENE-BUTADIENE RUBBER

2011 ◽  
Vol 84 (4) ◽  
pp. 507-519 ◽  
Author(s):  
C. G. Robertson ◽  
C. J. Lin ◽  
R. B. Bogoslovov ◽  
M. Rackaitis ◽  
P. Sadhukhan ◽  
...  
Keyword(s):  
Glass Transition ◽  
Coupling Agent ◽  
Volume Fraction ◽  
Polymer Chains ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Polymer Filler ◽  
Bound Rubber ◽  
Filler Network ◽  
Styrene Butadiene

Abstract The introduction of silanes to improve processability and properties of silica-reinforced rubber compounds is critical to the successful commercial use of silica as a filler in tires and other applications. The use of silanes to promote polymer–filler interactions is expected to limit the development of a percolated filler network and may also affect the mobility of polymer chains near the particles. Styrene-butadiene rubber (SBR) was reinforced with silica particles at a filler volume fraction of 0.19, and various levels of filler–filler shielding agent (n-octyltriethoxysilane) and polymer–filler coupling agent (3-mercaptopropyltrimethoxysilane) were incorporated. Both types of silane inhibited the filler flocculation process during annealing the uncured rubber materials, thus reducing the magnitude of the Payne effect. In contrast to the significant reinforcement effects noted in the strain-dependent shear modulus, the bulk modulus from hydrostatic compression was largely unaltered by the silanes. Addition of polymer–filler linkages using the coupling agent yielded bound rubber values up to 71%; however, this bound rubber exhibited glass transition behavior which was similar to the bulk SBR response, as determined by calorimetry and viscoelastic testing. Modifying the polymer–filler interface had a strong effect on the nature of the filler network, but it had very little influence on the segmental dynamics of polymer chains proximate to filler particles.

scholarly journals Compressive Fatigue Behavior of Gum and Filled SBR Vulcanizates

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1497
Author(s):  
Liu Yang ◽  
Lin Wang ◽  
Huaiqing Guo ◽  
Aihua Du
Keyword(s):  
Carbon Black ◽  
Fatigue Resistance ◽  
Fatigue Behavior ◽  
Polymer Chains ◽  
Styrene Butadiene Rubber ◽  
Propagation Mechanism ◽  
Butadiene Rubber ◽  
Sem Images ◽  
Crack Propagation Mechanism ◽  
Styrene Butadiene

The influence of carbon black on physical mechanical properties, compressive fatigue life, and the temperature changes during compression fatigue process of styrene-butadiene rubber (SBR) vulcanizates were explored. A series of unfilled and filled SBR compounds were prepared, and the compressive fatigue behaviors of the vulcanizates were performed on a mechanical testing and simulation (MTS) machine. The top surfaces of the filled SBR were imaged using scanning electron microscopy (SEM) after 105 cycles of compressive fatigue. The filled SBR shows greater compressive fatigue resistance than the unfilled SBR. The incorporation of carbon black into SBR improves the creep resistance. The best compressive fatigue resistance for the filled SBR was achieved by the addition of 30 phr carbon black. With the increase of carbon black content, the energy dissipation and the heat build-up increase simultaneously. Furthermore, SEM images of the vulcanizates suggest that the crack propagation mechanism of the unfilled and the filled SBR was different. For the unfilled SBR, due to periodical compressive stress, the polymer chains can be destroyed, and the cracks can be easily initiated and propagated, showing serious damage on the top surfaces of the specimen. However, for the filled SBR, the carbon black agglomeration around the cracks can greatly delay the generation of the cracks, decrease the fatigue damage, and ultimately improve the fatigue resistance.

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