Saturday, December 13, 2008

Glue

I know few Ford Retort readers would doubt my bona fides as a tried and true intellectual. My mind is frenetic as I'm always thinking about answers and solutions and philosophies and other universal quandries. I'm glad I have the brain I have, but I couldn't have my brain, I think I would want this man's brain.

Driving home the other day, I had a thought: why doesn't glue stick to the inside of a bottle? Hmm. So I clicked over to the Elmers website to search for an answer. And sure enough, it was there.

Glue is an aqueous solution of naturally "sticky" synthetic polymers (and a few other things). The solvent of that aqueous solution is of course water. When you pour glue out of it's a bottle onto, let's say a homemade Christmas card, a piece of macoroni, or a paper mache masterpice, the water in the glue solution quickly evaporates. This leaves behind the "sticky" polymers that adhere to the materials.

But when glue is in it's bottle, only a limited amount of the water in this aqueous solution is able to evaporate into the air (the free space in the bottle). Therefore, the glue solution remains liquid and doesn't stick to the sides.

So now you know.

2 comments:

andrew said...

I like this post. I have never questioned why glue doesn't stick to the inside of the bottle, but now I am glad I know.

UMC said...

i have a comment but I think I'll keep it to myself! i'm sure you know what it is! you can borrow my materials science book to fill in all the other gaps in your knowledge of structural, mechanical, and physical properties of materials! or perhaps, just apply to dental school and you will get more than enough of it!!