Why does acid break cross-linking?

Physical cross-links For example, sodium alginate gels upon exposure to calcium ion, which allows it to form ionic bonds that bridge between alginate chains. Polyvinyl alcohol gels upon the addition of borax through hydrogen bonding between boric acid and the polymer’s alcohol groups.

Why does HCl break down slime?

Optional: Adding acid (HCl) to the slime breaks the crosslinking and produces a liquid with lower viscosity. If you add a base (NaOH), the process is reversed and the slime is regenerated. The slime can be taken home by storing it in a ZipLoc bag.

What is the effect of adding borax to PVA solution?

The material becomes more viscous as we mix the PVA and the borax. It will reach a maximum level of viscosity and will not thicken further without more cross-linking agent. The addition of a higher ratio of Borax will result in a very viscous polymer (like Jell-O).

Is borax a cross-linking agent?

In this research, borax was introduced as a cross-linker in order to enhance stability and properties of the hydrogels prepared from water hyacinth fibers (WHFs), and effect of the borax contents on hydrogel properties was investigated.

Does the glue borax slime react the same as the PVA borax slime?

Now if you reach in and grab one chain, you’ll lift out the entire pile. Adding a Borax solution to the PVA does pretty much the same thing (only it’s a chemical, not a magnetic, connection). Borax loves to connect with water.

How does the amount of borax affect slime?

Borax is the key element in this process: by adding borax to water, borate ions are formed which help link these glue polymers together. Because of the role borax plays in slime Page 2 shape and formation, changing the amount of borax added to a slime solution should affect the stretchiness of the polymers present.

Why can PVA gels flow?

In the aqueous borax solutions of PVA, the gelation process occurs through intermolecular hydrogen bonds between hydroxyl groups on PVA chains because of the intervention of a borate anion. The crosslinking points are therefore exchangeable, which results in the gel flowing extremely slowly.

Is slime a cross linked polymer?

Slime is an example of a cross-linked polymer. Polymers are long molecules consisting of identical repeating structural units connected by covalent chemical bonds. School glue contains a polymer called polyvinyl alcohol. It’s this cross-linking that gives slime its characteristic feel.

What does PVA stand for?

Polyvinyl acetate
Infobox references. Polyvinyl acetate (PVA, PVAc, poly(ethenyl ethanoate)), commonly known as wood glue, white glue, carpenter’s glue, school glue, or Elmer’s glue in the US, is a widely available adhesive used for porous materials like wood, paper, and cloth.

Why does glue react with borax?

Borax in water forms an ion called the borate ion. When the borax solution is added to the glue solution, the borate ions help link the long polymer molecules to each other so they cannot move and flow as easily.

What can I add to PVA glue to make slime?

STEP 1: Measure 1/2 cup PVA washable school glue and add to a bowl. Mix with 1/2 cup of water. STEP 2: Stir in 1/4 tsp of baking soda (You can use 1/2 tsp for thicker slime). STEP 3: Add food coloring, glitter, or confetti to this mixture and mix to incorporate everything.

Does slime have borax in it?

This increases the viscosity of the polymer (glue). Besides Borax, other cross-linking agents include: Borax tends to be a harsh on your hands. For an almost borax-free fluffy slime you need white washable PVA school glue, foaming shaving cream, baking soda, and saline solution (contains both sodium borate and boric acid as ingredients).

Can I use borax in place of PVA?

If an 8\% aqueous solution of PVA is used an 8\% aqueous solution of borax will be required. Borax solid is now classified as TOXIC because it carries the R60/61 warning – it may cause infertility and harm to the unborn child.

How do you make slime with polyvinyl alcohol?

A solution of polyvinyl alcohol (PVA) can be made into a slime by adding borax solution, which creates cross-links between polymer chains. In this activity, some interesting properties of the slime are investigated. Students are guaranteed to enjoy the activities involved

What increases the viscosity of PVA glue?

These indivi dual chains of the PVA molecule slide across each other until a cross-linking agent is added such as borax, which is sodium tetraborate decahydrate (Na 2 B 4 O 7 • 10H 2 O). This increases the viscosity of the polymer (glue).