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Author Topic: What causes a rubber hot water bottle to corrode?  (Read 7013 times)

Offline FuzzyUK

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I just went to fill a rubber hot water bottle which I hadn't used since last year to warm my tootsies and it was all gluey and sticky to touch and a hole instantaneously appeared in it. So I dug out another one out of the cupboard and that had crinkled up. Small lumps were shedding off the inside in this particular case.

What causes rubber to corode after a period of time? Is it a chemical reaction rather like plastic sheet gets brittle after a number of years with exposure to UV light, or is it the long term use of hot water that is detrimental to it?


 

Offline Kerry

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What causes a rubber hot water bottle to corrode?
« Reply #1 on: 12/11/2009 14:35:36 »
It could be something to do with one of the additives added to the rubber to make it malleable.  I think plasticisers are added to plastic for a similar reason and they can leach out, especially in water, making the plastic brittle - which I believe is why you shouldn't refill water bottles.
 

Offline RD

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Offline Madidus_Scientia

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What causes a rubber hot water bottle to corrode?
« Reply #3 on: 12/11/2009 21:38:23 »
Regarding plastic leeching out of bottles - http://skeptoid.com/episodes/4060
 

Offline Kerry

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What causes a rubber hot water bottle to corrode?
« Reply #4 on: 13/11/2009 09:21:41 »
Re the plasticisers - I'm sure it's something we were taught at uni, and found this:
http://www.injuryboard.com/national-news/harvard-study-confirms-plastic-bottles-leach-bpa.aspx?googleid=263458 [nofollow]
 

Offline Geezer

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What causes a rubber hot water bottle to corrode?
« Reply #5 on: 13/11/2009 18:58:49 »
Regarding the degradation of rubber, I've heard it's not a failsafe idea to keep spare rubber gaskets/washers on hand in case the kitchen or bathroom sink needs one.  Apparently (over a few years), the rubber dries up, becomes brittle and cracks while sitting on the shelf.  The reason given to me was that the oils in the rubber gradually evaporate although, to me, they don't seem to be natural oils.  These are not the symptoms asked about here, but it indicates that rubber can degrade.

They might last a bit longer if you can keep them sealed in a container that is free of oxygen and does not admit any light. I suppose one of those vacuum food preservers might do the trick. I'm guessing the oxidation will also accelerate with increasing temperature. Will cold storage preserve them longer?
 

Offline Bored chemist

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What causes a rubber hot water bottle to corrode?
« Reply #6 on: 14/11/2009 16:51:43 »
" I think plasticisers are added to plastic for a similar reason and they can leach out, especially in water, making the plastic brittle - which I believe is why you shouldn't refill water bottles."
How does the bottle know it is being reused?

Anyway, oxygen in the air slowly degrades rubber.
 

Offline Kerry

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What causes a rubber hot water bottle to corrode?
« Reply #7 on: 17/11/2009 11:22:40 »
I thought the more you used the bottle, the more likely it was that the plasticiser leaches out?  I'm probably wrong though!
 

Offline Bored chemist

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What causes a rubber hot water bottle to corrode?
« Reply #8 on: 17/11/2009 19:06:02 »
The more you use the bottle the less there is left to leach out.
 

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What causes a rubber hot water bottle to corrode?
« Reply #8 on: 17/11/2009 19:06:02 »

 

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