Ozone Attack and Antiozonant Protection of Vulcanized Natural Rubber. A Surface Study by Attenuated Total Reflectance Spectroscopy

Abstract

This work reports a direct surface analysis of ozonization of vulcanized NR compounds by ATR. On ozonization of a vulcanized NR compound without clay filler or AO a degraded rubber layer, which contains ozonides and carbonyl compounds, is formed on the surface. This reaction is considerably slower than that of raw NR. When clay filler is added, the first effect is a decrease of rubber on the surface and a corresponding increase in the surface concentration of clay. With further ozone exposure, ozonides and carbonyl compounds appear. When a compound containing N,N′-dioctyl-p-phenylenediamine AO is ozonized, a film is seen, which has an ATR spectrum essentially identical to that of the ozonized liquid AO. There is no evidence of ozonized NR products, or of complex reaction products between AO and ozonized NR. These results are consistent with a scavenger or protection-layer mechanism for antiozonant protection.

Effect of the blooming of chemical curatives on the cyclic fatigue life of natural rubber filled with a silanized silica nanofiller

“…8). The presence of antidegradant in the bloom was expected because it migrated to the surface to protect the rubber against environmental ageing 16. Small traces of NR in the bloom was from the rubber surface during the sampling of the solid layer before the FTIR spectrum was taken.…”

Rubber

“…Examination of the surface of ozonized NR by attenuated total reflectance of infrared radiation revealed the presence of ozonides and carbonyl groups (8).…”

“…Birks and Gilfrich (2) in a general review of x-ray spectrometry devoted a section to its application to the field of water pollution. Elder, Perry, and Brady (8) reported that energy-dispersive x-ray fluorescence is a relatively recent development in the field of x-ray spectrometry that improves capability for rapid multielement analysis. Application of the technique to determine dissolved trace metals in water requires transfer of the dissolved elements to a uniform target suitable for analysis.…”

Ozonolysis of Natural Rubber: A Critical Review

“…Andries et al (21) studied the ozonisation of a vulcanised natural rubber (compounded without clay filler or antiozonant) and observed that the degraded rubber layer contained ozonides and carbonyl compounds on the surface and characterised it by ATR spectroscopy. The degradation rate was found slower than that of raw natural rubber.…”