Slime Synthesis (Cross-linked PVA)

Creating a non-Newtonian fluid by cross-linking polyvinyl alcohol

Organic Synthesis Beginner (Middle School) 20 min ~$5.00

Objective

Create slime by cross-linking polyvinyl alcohol (PVA) with sodium borate, demonstrating polymer chemistry and non-Newtonian fluid behavior.

Background

When sodium borate (borax) is added to polyvinyl alcohol, borate ions form cross-links between PVA polymer chains, creating a viscoelastic material known as slime. The product exhibits non-Newtonian behavior: it flows slowly under gravity but breaks when pulled sharply.

Safety Warnings

  • Borax is an irritant — avoid eye contact
  • Wash hands after handling slime
  • Do not eat the slime

Required PPE

goggles

Materials

  • Polyvinyl alcohol (PVA) solution (50 mL)
    4% solution or white school glue
  • Sodium borate (borax) (5 g)
    Dissolved in 50 mL water
  • Food coloring (2-3 drops)
    Optional

Equipment

250 mL beaker Stirring rod Measuring cylinder

Procedure

1

Pour 50 mL of PVA solution (or white school glue) into the beaker.

1 min
2

Add 2-3 drops of food coloring if desired and stir.

1 min
3

Slowly add the borax solution to the PVA while stirring continuously.

3 min
4

Continue stirring as the mixture thickens into slime. Knead with hands once it forms.

5 min Wash hands afterward
5

Test the non-Newtonian properties: roll into a ball, let it flow slowly, pull sharply to see it snap.

5 min
6

Experiment with the ratio of borax to PVA to change slime consistency.

5 min

Expected Results

A stretchy, squishy slime that flows slowly under gravity but breaks when pulled quickly. More borax makes stiffer slime; less makes it more fluid. The cross-linking is reversible — slime will slowly become more liquid over days.

Cleanup

Slime can be disposed of in the trash. Wash hands with soap and water. Rinse beaker with warm water.

Details

Category
Organic Synthesis
Difficulty
Beginner (Middle School)
Duration
20 min
Est. Cost
$5.00
Steps
6
Materials
3

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Frequently Asked Questions

What is the objective of Slime Synthesis (Cross-linked PVA)?
Create slime by cross-linking polyvinyl alcohol (PVA) with sodium borate, demonstrating polymer chemistry and non-Newtonian fluid behavior.
How difficult is Slime Synthesis (Cross-linked PVA)?
This experiment is rated as Beginner (Middle School). It takes approximately 20 minutes to complete.
What safety precautions are needed for Slime Synthesis (Cross-linked PVA)?
Key safety precautions include: Borax is an irritant — avoid eye contact; Wash hands after handling slime; Do not eat the slime.
What materials are needed for Slime Synthesis (Cross-linked PVA)?
The main materials required are: Polyvinyl alcohol (PVA) solution, Sodium borate (borax), Food coloring.
What results should I expect from Slime Synthesis (Cross-linked PVA)?
A stretchy, squishy slime that flows slowly under gravity but breaks when pulled quickly. More borax makes stiffer slime; less makes it more fluid. The cross-linking is reversible — slime will slowly become more liquid over days.