Sulphur bond strength

It should be recognized that appreciable shifts in bonding strength are sometimes made possible by special compounding variations for instance, the heat resistance of NR vulcanizates may be improved considerably by variation of the vulcanizing system. The normal sulphur vulcanization system is capable of many variants, which will govern the chemical nature of the sulphur cross link, i.e., whether it is essentially a more, di, or poly-sulphide type. The nature of sulphur cross link can have considerable influence on the bond strength and the heat-resistance of vulcanizate... 

Wilde et al.120 and Paal121 consider that metal-sulphur bonds are stronger than metal-carbon bonds, and that sulphur can displace carbon from Pt. The strength of irreversible sulphur adsorption is in the order Re > Pt-Re > Pt. 

BOND STRENGTHS IN SILICON, PHOSPHORUS AND SULPHUR C03IP0LNDS... 

Analysis of the results shows that there are very small differences in the discriminating ability of one complex against the various entering amines, whereas, when the reactivity of the series of complexes towards a given amine is compared, there is a marked decrease in rate when the donor ability of the sulphur atom is increased i.e. the lability decreases when the bond strength increases. ... 

The level and consistency of bond strength are influenced by the nature of the rubber factors include the mix viscosity, level of filler, scorch safety and, in the case of sulphur-vulcanized rubbers, the amount of elemental snlphur in the vulcanizing system. 

The hardness of the componnd will also become a significant factor the harder the compound the lower will be its ability to deform and follow the contonrs of the metal surface this will affect the level of FSq. If however the increase in hardness of the rubber compound is produced by the addition of sulphur then there will be an increase in the chemically active units on the nitrile rubber surface and thus bond strength because of copper/sulphur bonds being formed gives an increase in FS. 

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