Tackification Studies of Natural Rubber/Styrene-Butadiene Rubber Blends

1982 ◽  
Vol 55 (2) ◽  
pp. 416-427 ◽  
Author(s):  
Bruce C. Copley
Keyword(s):  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Sharp Transition ◽  
Rolling Ball ◽  
Rubber Blends ◽  
Transition Zones ◽  
Pressure Sensitive Adhesives ◽  
Pressure Sensitive ◽  
Styrene Butadiene ◽  
Steel Properties

Abstract A 50:50 blend of NR and SBR 1011 is heterogeneous. When tackified with a resin which is compatible with the NR phase, but not the SBR phase, the resin appears to partition unequally between the NR and the SBR. The resulting heterogeneous pressure-sensitive adhesives exhibit very broad storage modulus transition zones. The increased breadth occurs predominantly at the lower frequency portion of the transition. This is quite different from the NR/SBR blends tackified with a resin which is compatible with both NR and SBR. The NR/SBR blend with compatible resins exhibits a single sharp transition which is similar in character to either pure NR or pure SBR adhesives prepared with completely compatible resins. The differences due to heterogeneity are clearly manifested in the mechanical properties of the blend and are reflected by the rolling ball tack and shear strength to steel properties. Rolling ball tack data are consistent with the hypothesis that the NR phase is more highly tackified than is the SBR phase. Shear adhesion to steel data further support this conclusion.

Properties and Control of “Stickies” in Paper Recycling

MRS Bulletin ◽  
1994 ◽  
Vol 19 (2) ◽  
pp. 36-40
Author(s):  
Mahendra R. Doshi
Keyword(s):  
Ethylene Vinyl Acetate ◽  
The United States ◽  
Soya Protein ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Pressure Sensitive Adhesives ◽  
Pressure Sensitive ◽  
And Control ◽  
Styrene Butadiene ◽  
Coating Formulations

Large amounts of waste paper are generated every day and interest in its reuse has increased steadily due to environmental concerns and improved economics. In 1990 in the United States, for example, 28.9 million tons of recovered papers were collected for recycling. By 1995, that amount is expected to increase to almost 40 million tons with a collection rate of almost 40%. To facilitate the use of secondary fibers, sticky contaminants, or “stickies,” must be controlled.Classification and Properties of StickiesRecovered paper bales usually contain extraneous materials such as sand, glass, staples, nails, inks, coatings, plastic, styrofoam, wax, EVA (ethylene vinyl acetate), and SBR (styrene butadiene rubber). A particularly troublesome contaminant in recovered paper is “stickies” which, in their original state, were used as paper adhesives. Inks and coatings can also be a source of stickies. Inks are primarily composed of a pigment, liquid vehicle, binder, and modifier. Coating formulations contain several ingredients that can be classified as pigments, binders, and additives, such as plasticizers, thickeners, dispersants, dyes, preservatives, and defoamers. Note that both inks and coatings mixtures contain binders which contribute to the stickies problem. Common binders used in inks are hydrocarbon resins and rosin esters while those used in coating formulations include starch, soya protein, acrylics, and polyvinyl acetate. An overview of stickies was presented by Moreland.Stickies can be classified into three categories: hot melts, pressure-sensitive adhesives, and latexes. Although wax can be a contaminant, it is not included separately because it is similar to and an important ingredient of most hot melts.Contaminants such as plastics and styrofoam are also excluded from this discussion because they are not stickies.

Characterization of Sulfur-Cured Styrene-Butadiene Copolymer Rubbers and Their Polybutadiene Blends

1970 ◽  
Vol 43 (6) ◽  
pp. 1332-1339 ◽  
Author(s):  
J. K. Clark ◽  
R. A. Scott
Keyword(s):  
Carbon Disulfide ◽  
High Speed ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Absorption Bands ◽  
Rubber Blends ◽  
Cast Films ◽  
Micro Structures ◽  
Styrene Butadiene

Abstract Dissolution of sulfur-cured, carbon black-loaded copolymers and their blends with cis-1,4-polybutadiene (PBD) are brought about by boiling with o-dichlorobenzene which contains a small amount of 2,2′-dibenzamidodiphenyl disulfide. The resulting slurries are subjected to a sequence of separations which include high-speed centrifugation to remove solids, and solvent precipitation followed by filtration to isolate the precipitates. The precipitates are washed with solvent to remove soluble organic materials followed by carbon disulfide washing to dissolve the polymers. Cast films of the polymers are obtained by evaporating the carbon disulfide washings onto sodium chloride discs. The infrared spectra of the cast films of these preparations are very similar to those of their respective polymers prior to loading and curing. Calculations for relative concentrations of bound styrene and PBD micro-structures permit nominal identification of the kinds of styrene-butadiene rubber and the amounts of cis-1,4-PBD used in a cured rubber formulation. Absorption bands used are near 3.35 μ for cis-1,4-PBD, 6.65 μ for bound styrene, 10.35 μ for trans-1,4-PBD; and 11.0 μ for vinyl-1,2-PBD. Efforts are being made to improve the data by using a grating infrared instrument and also to extend the calibrations to include other rubber blends.

Novel modification of styrene butadiene rubber/acrylic rubber blends to improve mechanical, dynamic mechanical, and swelling behavior for oil sealing applications

2021 ◽  
pp. 096739112110313
Author(s):  
Ahmed Abdel-Hakim ◽  
Soma A el-Mogy ◽  
Ahmed I Abou-Kandil
Keyword(s):  
Mechanical Properties ◽  
Crosslink Density ◽  
Physical And Mechanical Properties ◽  
Dynamic Mechanical Properties ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Rubber Blends ◽  
Dynamic Mechanical ◽  
Oil Resistance ◽  
Styrene Butadiene

Blending of rubber is an important route to modify properties of individual elastomeric components in order to obtain optimum chemical, physical, and mechanical properties. In this study, a novel modification of styrene butadiene rubber (SBR) is made by employing acrylic rubber (ACM) to obtain blends of outstanding mechanical, dynamic, and oil resistance properties. In order to achieve those properties, we used a unique vulcanizing system that improves the crosslink density between both polymers and enhances the dynamic mechanical properties as well as its resistance to both motor and break oils. Static mechanical measurements, tensile strength, elongation at break, and hardness are improved together with dynamic mechanical properties investigated using dynamic mechanical analyses. We also proposed a mechanism for the improvement of crosslink density and consequently oil resistance properties. This opens new opportunities for using SBR/ACM blends in oil sealing applications that requires rigorous mechanical and dynamic mechanical properties.

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