Polymer degradation into the bore of the pipe, and fuel leakage and fire may follow. The problem of ozone cracking can be prevented by adding anti-ozonants to the rubber before vulcanization. Ozone cracks were commonly seen in automobile tire sidewalls, but are now seen rarely thanks to these additives. On the other hand, the problem does recur in unprotected products such as rubber tubing and seals. The polymers are susceptible to attack by atmospheric oxygen, especially at elevated temperatures encountered during processing to shape. Many process methods such as extrusion and injection moulding involve pumping molten polymer into tools, and the high
Natural rubber using gas chromatography/mass spectrometry (GC/MS) and gas chromatography (GC) indicates that they contain sulphur, ammonia, alkenes, ketones, esters, hydrogen sulphite, nitrogen, and low molecular weight fatty acids (C2-C5). When latex concentrate is produced from rubber, sulphuric acid is used for coagulation. This produces malodourous hydrogen sulphide. The industry can mitigate these bad odours with scrubber systems. Latex is the polymer cis-1,4-polyisoprene – with a molecular weight of 100,000 to 1,000,000 daltons. Typically, a small percentage (up to 5% of dry mass) of other materials, such as proteins, fatty acids, resins, and inorganic materials (salts) are found in natural rubber. Polyisoprene