'Scientific' question

OK - here's one for you science buffs out there.
Just now, I was doing a bit of routine maintenance on my helmet (Cue fnarr et al)
I cut off some of the excess strap last week and by the end of a week's commuting it had frayed a bit. Not fancying a bushy pom pom under my chin, I decided to glue the strands with super glue. Applying the glue to the strands in a sort of wiping fashion, I saw 'smoke' - real fumes coming from the glued area of the strap.

What's all that about?
 

freakhatz

New Member
Why didn't you cut the straps with a nearly red hot knife? That would do both jobs at once and you'd still get plenty of smoke as well.
 

Cycling Naturalist

Legendary Member
Location
Llangollen
Aperitif said:
Yes - me too!

Still no science. Holy helmet straps Batman!:biggrin:

What I would like to know is; why does the application of super glue to nylon? (polyprop etc)filaments cause smoking to occur on contact?:sad: :biggrin:

Because you've created an exothermic reaction with inflammable materials.
 

Abitrary

New Member
Patrick Stevens said:
Because you've created an exothermic reaction with inflammable materials.
Hmmm, this might be falling for the old no smoke without fire story.

There might be fumes, but unless there was extreme heat and possible flames, it could have been an endothermic reaction.
 
Thanks Patrick and Abitrary

This could also be the seedling of an explanation as to why yenrod's pants caught fire after he placed them in the oven last week...

...and innuendothermic reaction perhaps...or worse?:biggrin:
 

redshift

Über Member
Abitrary said:
Hmmm, this might be falling for the old no smoke without fire story.

There might be fumes, but unless there was extreme heat and possible flames, it could have been an endothermic reaction.
Polymerization of cyanoacrylates is exothermic. Also, cyanoacrylates and cotton don't mix.

The strap presumably isn't cotton, more probably a polyester, but it's probably been impregnated with some skin acids (also cause exothermic reactions) and the resisdual water is what causes the glue to cure in the first place. It may just have been water vapour if the reaction's vigorous enough, combined with the usual fumes and by-products.*


*I'm winging it. It's over 20 years since I considered myself a 'chemist!' :biggrin:
 

longers

Veteran
We use quite a bit of Superglue at work and have activator sprays to get it to go off instantly. It's so much more convenient for sticking your fingers together with.
 

domtyler

Über Member
I know the answer and could probably explain it in plain English, but the sad fact remains that there are so few people on this forum with the mental nouse to comprehend the complexity of my answer that I may as well not bother. So I won't. ;)
 
Top Bottom