Why is glue sticky?

Good question. Although I do not know for sure, I can hazard a WAG.

There are primarily three methods to stick things together:
1: mechanical, like velcro. This is out, because glue, being a liquid, has no consistent structure to stick to.

2: magnetic: also out, because, well, glue isn’t magnetic.

3: chemical. This is what we’re left with. I suppose that the glue has a lot of molecules that can form weak bonds with most anything. Not stronger ionic bonds probably, because glue is rarely considered chemically active.

Anyone with a real clue going to tackle this?

Adhesives an article on medical adhesives but some general info on how adhesives work.

“Adhesives are liquids that must be converted to a solid state. Those that are commonly used in medical device manufacture achieve this change through polymerization, also known as “curing.” There are many curing processes available, and many adhesive systems use more than one; therefore, it is best to consider each process individually. A summary of bonding processes and the trade-offs associated with each are shown below.”

And here is a bit of info from Cecil:


Dang Tom I knew he’d done one sometime. Should’ve searched for adhesives instead of glue.

Here’s some more info:

The short answer: it depends.