What causes rubber bands to deteriorate?

'Rubber' is many different compositions. Rubber from many years ago was actually rubber from the tree. Most rubber today is synthetic and not exactly the same chemical composition as natural. It is the impurities in rubber that cause it to deteriorate. Any unsaturations in the polymer can be oxidized by the atmosphere leading to breakage of the polymer chains. Natural rubber has very little unsaturation, while synthetic has significantly more. Exposure to oxidizing environments can speed the deterioration process. A common example is the environment around electric motors. The ozone generated by sparking is a very powerful oxidant.

john

Hummm..I live in the oil fields and Hydrogen disulfide is very common. I wonder if that kills some rubbers?

Gunner

"Gun Control, the theory that a 110lb grandmother should fist fight a 250lb 19yr old criminal"

Actually the pencil has never been sharpened, is red, and has my middle name, which I don't use anymore printed on it. Personalized pencils were fairly popular as a Christmas gift (to oneself) and I think was part of a project to make money for some school function when I got this in the third or fourth grade. The eraser only has very slight use in the past year. This pencil somehow got laid away. My other pencils of that era and through grade school and junior lasted a very short time. I ate the erasers off, chwed on the pencil until the brass ferrule fell off and then continued to chew on the end of the pencil until it became very short. Fortunately I cured myself of that habit before ball point pens became popular. Now about those Lone Ranger items purchased for 25 cents each with a Cheerios box top, they are in a box on a shelf in the bedroom.

snip

Ah, yes, the old Tom Leher song :

"Relations sparing no expensal send some useless old utensil, or a matching pen and pencil. Just the thing I need... How nice..."

Neat!

The oldest artifact from my youth that I can still put my hands on is the copies of Astounding Science Fiction in which 'Dune' was originally serialized...but my age must have been pushing double digits by then...

Mickey

On Sun, 11 Jan 2004 20:46:22 GMT, "George E. Cawthon" wrote: This pencil somehow got laid away. My other

I remember the look on Mother's after I chewed up the indelible pencil someone had left lying around. I guess I was not a pretty sight!

Gerry :-)} London, Canada

Ever watch the John Wayne show - Red Adair type - they indicated it did in a poison gas well they went to cap off.

That stuff creates so many different acids when it starts mixing with water and other pollutants. Add some chlorine (likely in the rubber) and a fancy acid is produced. It will eat gold.

Mart> >

Gerald Miller wrote: (clip) the indelible pencil someone had left lying around. (clip) ^^^^^^^^^^^^ Now, THAT brings back memories. I don't think my father ever owned a fountain pen. He wrote all his checks with an indelible pencil, activated with saliva spread with his middle finger. I don't know whether he though his index finger wasn't clean enough, or not the right shape.

On Sun, 11 Jan 2004 20:46:22 GMT, "George E. Cawthon" vaguely proposed a theory ......and in reply I say!:

I can still remember sitting in school and hearing a disgusted retching sound from near the back of the class. Some guy had chewed the end off his biro, and then sucked the ink back into his mouth. It caused a bit of a stir for a bit, because it was red ink.

I was frightened by the idea of a conspiracy that was causing it all. But then I was terrified that maybe there was no plan, really. Is this unpleasant mess all a mistake?