why glue remains liquid inside the bottle and dries outside?
Answers
Answer:
Nice Question
Explanation:
Because there isn’t enough air to evaporate the solvent present inside the glue.
When you put glue on a piece of paper, the solvent — water — is exposed to air. The water eventually evaporates (changes from a liquid to a gas). As the water evaporates, the glue dries and hardens. All that's left are the sticky polymers that hold things together. This process is called mechanical adhesion.
So why doesn't white glue stick to the inside of the bottle? When white glue is inside a bottle, there's not enough air inside the bottle to cause the water to evaporate to make the glue sticky. Basically, the bottle protects the glue from the air and keeps the glue runny. If you've ever left the top off a glue bottle for a while, you may have noticed that, unfortunately, the glue dried up!