Artefacts rubber

Solutions in contact with polyvinyl chloride can become contaminated with trace amounts of lead, titanium, tin, zinc, iron, magnesium or cadmium from additives used in the manufacture and moulding of PVC. V-Phenyl-2-naphthylamine is a contaminant of solvents and biological materials that have been in contact with black rubber or neoprene (in which it is used as an antioxidant). Although it was only an artefact of the separation procedure it has been isolated as an apparent component of vitamin K preparations, extracts of plant lipids, algae, livers, butter, eye tissue and kidney tissue [Brown Chem Br 3 524 1967]. 

Disks faced with PTFE should be used in the head-space vials as some solvents may be absorbed by butyl-rubber caps. Contamination of samples with chloroform, usually from the laboratory environment, is common. An artefact eluting with a retention time of 33.2 minutes derives from the gas-chromatograph septa. 

C. Ward and Y. Shashoua, in Interventive conservation treatments for plastics and rubber artefacts in the British Museum, 12th Triennial Meeting of ICOM-CC, vol. 2, pp. 888-893 J. Bridgland (ed), James and James, London, 1999. 

Ward, C. and Shashoua, Y. (1999). Interventive Conservation Treatments for Plastics and Rubber Artefacts in the British Museum. In Preprints of 12th ICOM-CC Triennial Meeting Lyon, 29 August-3 September 1999 (J. Bridgland ed.) pp. 888-893, James James Ltd. 

The synthesis site for allylic diphosphate primers and cw-polyisoprene is largely assumed to occur on the surface of pre-existing rubber particles, but rubber biosynthesis activity has also been localized in the membrane of non-rubber particles from the bottom fraction after ultracentrifugation of latex. " The latter authors " presumed that previous localization of rubber biosynthesis on rubber particles was due to an artefact resulting from the rapid deterioration of bottom fraction (BF) particles after tapping, which led to the migration of rubber synthesis machinery from BF particles to rubber particles. 

However, for making a reliable and representative analysis, a large number of thin sections, obtained by cryomicrotomy from different zones of the composite, are required. Moreover, during the preparation of the thin eryoseetions, cutting artefacts can be produced in the case of highly loaded rubber and plastics. They appear as dark striations with the same opacity of the filler agglomerates and they must be eliminated by image analysis software. 

Figure 5.2 Electron micrograph of the typical microstructure of a rubber-toughened epoxy adhesive showing the dispersed rubbery phase of particles in the matrix of a thermosetting epoxy polymer. (TTie wavy lines are artefacts due to the cutting of a very thin section of material.)...

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