:lol:
Regular, white glue is made from various synthetic chemicals. The chemical molecules are in the form of polymers, or long strands. Some are sticky, and others are stretchy. The proper combination of stretchy and sticky polymers make good glue. White glue also contains water. When the glue is exposed to air, the water evaporates, and the glue hardens and dries. When you glue things together with white glue, it's the evaporation of the water that allows the bond to hold. This is called mechanical adhesion. In the bottle, the water within the glue is protected from air. It remains in the glue, and the glue stays in its liquid state. That's why it doesn't stick to the inside of the bottle.