Science, Tech, Math › Science Why Doesn't Glue Stick to the Inside of the Bottle? Chemical Reaction Between Glue and Air Share Flipboard Email Print You can stick glue to the outside of the bottle to prove to yourself there is nothing magical about the type of plastic used in the bottle. Fuse, Getty Images Science Chemistry Chemistry In Everyday Life Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated July 03, 2019 Most glue doesn't stick to the inside of the bottle because it needs air in order to set. If you leave the cap off of the bottle or as the bottle gets closer to empty so that more air is inside the bottle, the glue will get stickier. Some types of glue require a chemical other than those found in air. These types of glue won't stick to the bottle even if you leave the cap off. In some cases, there is a solvent in the glue that helps keep the molecules in the glue from cross-linking (getting sticky). The glue doesn't solidify in the bottle or stick to it because of the solvent. The solvent evaporates in a half-empty bottle of glue, but this is limited by the space in the bottle. If you've ever left the cap off of a bottle of glue, you know it's capable of sticking just fine once the composition has had a chance to set up! This also occurs when a bottle of glue is close to empty. The air in the bottle thickens the glue, eventually making the product unusable.