Sorry for the confusing title, I didn't know how to describe this better. So, if we douse rubber, say, a bicycle tire or a certain type of rubber glove, with organic solvent (n-heptane), we can find n-alkanes being dissolved in the solvent. Why is this? I'm talking especially about gas chromatography to analyse the paraffinic hydrocarbons here.
I guess this is quite a trivial question but I can't figure it out. As far as I know, natural rubber consists mainly of isoprene polymer chains. But isoprene has a double bond and in GC chromatogram we can see n-alkanes being the largest peaks. And not only that, we can also find straight chain hydrocarbons in synthetic rubber (like NBR or SBR) solvent extracts. SBR has a benzene ring in its structure but still n-alkanes are the dominant finding in its solvent extract chromatogram.
This is a major subject in my bachelor's thesis but I'm an analytical chemistry major and struggling a bit with materials science in this depth. Any advice and ideas would be greatly appreciated.
To make my point clearer I present these two chromatograms:
(GC-FID run of pure n-heptane)
(GC-FID run of n-heptane extract of bicycle tire)
This question still haunts me. I found this. Could that be a partial explanation for the aliphatic hydrocarbon finding?