EFFECT OF THE CHEMICAL NATURE OF FILLER SURFACE AND IONIZING RADIATION ON THE PROPERTIES OF RUBBERS
The effect of the chemical nature of the filler surface on the physicomechanical properties of rubbers was studied. Butadiene-styrene (SKS-30), nitrile (SKN-40), and sodium butadiene (SK3) rubbers loaded with unmodified silica and with silica whose surface hydroxyls had been substituted by allyloxy or vinyl radicals were used. Use of modified silica in standard rubber mixes (containing 100 parts rubber and 50 to 80 parts filler) was shown to improve the physicomechanical properties of the vulcanizates. For example, the tensile strength of SKN-40 rubber containing 60% filler increased from 126.3 kg/cm/sup 2/ with unmodified silica to 163.6188 kg/cm/sup 2/ with vinyl-substituted silica (vinyl silica). This improvement was attributed to greater compatibility of the filler and the rubber and to a reaction bceween the olefin radicals of the filler surface and the rubber with the possible formation of C-C and C- S- C linkages. The effects of ionizing radiation from a Co/sup 60/ source at a dose rnte of 77 r/ sec on nonloaded SKS-30 rubber and on SKS-30 loaded (ratio 1/1) with unmodified and with modified silica (Belaks) containing 2.5% vinyl, methyl, or ethyl radicals was also studied. Irradiation did not affect the tensile strength and the modulus at 100% elongation of unloaded rubber but considerably improved these properties in loaded rubbers, particularly with vinyl silica. The maximum effect of irradiation was attained after 48 hr. These results were attributed to the participation of the filler in the formation of the three-dimensional network. It was concluded that the structure and the physicomechanical properties of vulcanizates can be controlled by modifying the nature of the organic radicals on the silica surface, the number of such radicals, the composition of the vulcanizates, and the method of vulcanization. (TCO)
- Research Organization:
- Originating Research Org. not identified
- NSA Number:
- NSA-17-040879
- OSTI ID:
- 4690756
- Journal Information:
- Kauchuk i Rezina, Vol. Vol: No. 6; Other Information: Orig. Receipt Date: 31-DEC-63
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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Related Subjects
ACRYLIC ACID
ALKYL RADICALS
BUTADIENE
CHEMICAL REACTIONS
COBALT 60
CYANIDES
ELASTOMERS
ETHYL RADICALS
FILLERS
GAMMA RADIATION
GAMMA SOURCES
IONIZING RADIATIONS
IRRADIATION
MECHANICAL PROPERTIES
METHYL RADICALS
MIXING
POLYMERS
POWDERS
RADIATION CHEMISTRY
RADIATIONS
RUBBER
SILICON OXIDES
SODIUM COMPOUNDS
STYRENE
SURFACES
TENSILE PROPERTIES
VINYL RADICALS
VULCANIZATION