At its core, slime is a science experiment. Slime is classified as a non-newtonian fluid, meaning it is neither a liquid nor a solid and has properties of both.
Slime is made up of polymers, which are made of long chains of molecules that bind together when the ingredients blend.
Here’s a chemistry breakdown.
There's many types of glue, but we use glues that contain PVA (polyvinyl acetate). PVA molecules are long polymer molecule chains that are tangled together, creating a thick viscous liquid.
Fun fact: most store bought slimes do not use polyvinyl acetate but organosiloxane (silicones) polymers or polyvinyl alcohol, making them more durable with a longer shelf life (but not the same delicious texture as hand made artisanal slimes).
2. Sodium Borate
If glue is our "adhesive," borax is our “binder.“ It is technically an alkaline mineral salt that has a grainy powdery texture. When borax dissolves in water, it makes what is known as activator. Mixing this with our glue (in small amounts!) binds the molecules of glue to themselves, forming slime.
We're all familiar with our friend water and how it helps us daily, but what role does it play in our slime?
Water is the other half of activator; it’s crucial in the chemical reactions to make slime. It also acts as a softener. It helps soften slime that may be a little too hard and it can be used to make a wiggly jiggly texture.
4. Vegetable Glycerin
We use vegetable glycerin (AKA glycerol), which is derived from oils such as palm, coconut, or soybean, all rich in triglyceride. When combined with lye (or a strong alkali), heated and pressurized, the fatty acids separate, leaving behind our trusty friend: glycerin.
We use glycerin to soften our slimes. It breaks down some of the molecule chains, adding softness and stretch. If you let it sit, it adds a great gloss to the look of slime.