Why Doesn't Glue Stick to the Inside of a Bottle?
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White Glue
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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.
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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.
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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.
Superglue
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Superglue, such as Krazy Glue, works slightly differently. It's made of a chemical called ethyl cyanoacrylate. This reacts with water vapor in the air to form an adhesive bond, via chemical adhesion.
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No matter how dry it is where you live, there's some water vapor in the air. That's why superglue tends to dry out more quickly in its container than white glue does---it's hard to reclose the container tightly enough to prevent water vapor from seeping in. But in a never-opened container (or a well-closed one), even superglue will remain in its liquid form and won't stick to the inside of the container, as long as it's protected from its nemesis: water.
Summary
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So water is crucial to both white glue and superglue, but it has opposite effects. As long as water is still present in white glue, the glue will remain liquid. But water has to be kept out of superglue, or else the glue will dry up.
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