From: muratlanne@gmail.com   
      
   "Clare Snyder"  wrote in message   
   news:vcadjjta7qb14jlee2r76lk1394hrvncji@4ax.com...   
      
   The carbonyl [C=O] end groups which are formed are usually aldehydes or   
   ketones, which can oxidise further to carboxylic acids. The net result   
   is a high concentration of elemental oxygen on the crack surfaces,   
   which can be detected using energy-dispersive X-ray spectroscopy in   
   the environmental SEM, or ESEM. The spectrum at left shows the high   
   oxygen peak compared with a constant sulfur peak.   
   ---------------------------------   
   That's slightly wrong like much of Wiki. Aldehyde implies an oxygen at the   
   end but a ketone has oxygen hanging off in the middle. Chemistry is too   
   complex for simple explanations. My 4 year degree in it qualified me only to   
   understand further education which the Vietnam draft prevented, though the   
   knowledge of matter, energy and quantum mechanics gave me a boost into other   
   fields like semiconductor physics.   
      
   Sulfur is mixed into raw rubber to react with the C=C sites, but with   
   different consequences, being less aggressive than its cousin oxygen it   
   hardens and stabilizes, "vulcanizes", the rubber instead of enabling further   
   degradation. It's the reason burning rubber smells bad.   
      
   Linseed and other "unsaturated" (double-bonded, -C=C-) plant-based oils   
   cross-link and harden in air by a similar process. The fire hazard from a   
   covered waste can of oily rags was caused by the feedback loop of oxidation   
   releases heat and heat speeds further oxidation. The mineral oils that   
   replaced them in machining have fewer double bonds and don't heat up.   
   "Paraffin" is from Latin "parum affinitas" and means low reactivity.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)