PHASE SELECTIVE LOCALIZATION OF FILLER IN TERNARY RUBBER BLENDS

2011 ◽  
Vol 84 (1) ◽  
pp. 41-54 ◽  
Author(s):  
H. H. Le ◽  
S. Ilisch ◽  
D. Heidenreich ◽  
K. Osswald ◽  
H-J. Radusch

Abstract The present work introduces a new concept based on the analysis of the rubber–filler gel for the determination of the phase selective filler localization in ternary rubber blends. Natural rubber (NR)/styrene–butadiene rubber (SBR)/ethylene–propylene rubber (EPDM) blends filled with silica were the focus of the experimental investigations. Because of the higher wetting rate of the NR component to silica, in the first stage of the preparation of SBR/NR/EPDM blends, more silica is found in the NR phase than in the SBR and EPDM phase. In the subsequent stage, silica is transferred from the NR phase to the SBR phase until the loosely bound NR-layer at the silica surface is fully replaced by SBR molecules. An extremely low amount of silica was found in the EPDM phase because of the poor EPDM–silica interaction. After a long mixing time, a large amount of silica whose surface was not yet wetted by any rubber phase could be found in the composites that can lead to fatal effects on the mechanical performance of the composites.

1970 ◽  
Vol 43 (6) ◽  
pp. 1332-1339 ◽  
Author(s):  
J. K. Clark ◽  
R. A. Scott

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.


2021 ◽  
pp. 096739112110313
Author(s):  
Ahmed Abdel-Hakim ◽  
Soma A el-Mogy ◽  
Ahmed I Abou-Kandil

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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