A lower amount of sulfur is thus available for the formation of the active sulfurating
species based on Zn and the aromatic moiety of the sulfenamide (ref.
The Zn-accelerator complex interact with sulfur or sulfur donors to form the very active sulfurating agent, which reacts with allylic sites of rubber chains to form increased number of crosslink precursors (24).
5b) exhibits slight agglomeration of nano ZnO particles in the NR matrix; the agglomeration of nanoparticles decrease the rate of adsorption of accelerators, sulfur, and stearic acid on its surface and further formation of Zinc Sulfurating complex hence the low cure rate index for NR--N2.
Once in solution the accelerator reacts with activators such as stearic acid and zinc oxide and ultimately with the sulfur to form the active sulfurating
It is believed that soluble zinc can form complexes with accelerator fragments that, when reacted with sulfur, may form the active sulfurating
With MBTS-accelerated sulfur vulcanization, a sulfurating
agent is formed which is the species that creates crosslinks in the compound.
This suggests the formation of a sulfurating
agent or other complex that might readily crosslink butyl rubber is not easily generated.
The model compound vulcanization approach (MCV) was used to characterize the vulcanization kinetics in terms of evolution of accelerators, active sulfurating
intermediates and sulfur.
Keywords: By reacting an alkoxysilane acetal with a sulfurating
agent including certain novel mercapto silanes, useful in providing rubber tires with improved properties.
Recently, quantitative structure activity relationship studies have shown strong correlations between structures representing a `representative' sulfurating
agent and scorch delay and cure kinetics.
The changes in physical properties and cure kinetics, and the improved reversion resistance suggest that either the mechanism of sulfuration has changed, or the nature of the active sulfurating
species is unique when HTS is employed.
An interaction of the curatives occurs to form what is termed the active sulfurating