"Andy" wrote in message
...

"Mary Fisher" wrote in message
. net...

"Phil Addison" wrote in message
...
What's happened to rubber bands? About 10% of my mixed stock are in
various stages of decay. I suppose this is something to do with being
eco friendly, but it means I can't trust them any more for holding stuff
together for more than a few weeks.

Can you still buy good ol' rubber bands? What's the decay process of the
eco ones - does they decay from manufacture or is it initiated by the
first stretch?

Phil

On my experience the old ones used to do what I can only describe as
'melt' and stick to everything.

Modern, presumably plastic, ones keep good for years.

Light doesn't have a good effect on the old ones.

Mary

I'm guessing at the decay process, but natural rubber is stabilised by a
process called vulcanisation, whereby sulphur creates cross linking
between the rubber molecules, stabilising them. Remove that sulphur, maybe
by a process of oxidation, I don't know, and possibly a stcky natural
rubber is the result again.

You're right but I didn't want to show off :-)

Mary

Just a guess,

Andy.