Wh. Waddell et al., MECHANISM BY WHICH PRECIPITATED SILICA IMPROVES BRASS-COATED WIRE-TO-NATURAL RUBBER ADHESION, Rubber chemistry and technology, 69(1), 1996, pp. 48-58
Quantitative determination of elements in the interfacial growth layer
formed on brass-coated wire when reacted in squalene suspensions cont
aining carbon black and curatives, with and without precipitated silic
a and an organocobalt adhesive, was accomplished by using direct surfa
ce characterization techniques: Scanning Electron Microscopy with Ener
gy Dispersive Analysis of X-rays (SEM-EDX), Auger Electron Spectroscop
y (AES), X-ray Photoelectron Spectroscopy (XPS) and Proton Induced X-r
ay Emission (PIXE) Spectroscopy. The effects on elemental changes in t
he interfacial growth layer upon addition of silica and/or cobalt neod
ecanoate to the squalene suspensions were statistically analyzed. Sinc
e the mechanism for silica improvement of brass-coated wire-to-rubber
adhesion was previously shown not to be a simple effect of improving r
ubber physical properties, a chemical mechanism is proposed involving
silica to reduce the thickness of the interfacial growth layer and to
change the relative concentration of compounds formed in the interfaci
al growth layer.