Think Polymerization! Fix a Crack in Classroom Wall

Students often find scientific words daunting, like the word-Polymerization. It is hard sometimes to visualize a certain chemistry reaction, especially when students are just trying to study the chemistry concepts only from the textbook. During STEM activity, a student is inspired to conduct a research related with self-healing cements after reading a scientific journal by Kanellopoulos et al., 2015. However, the student was having difficulty to understand the reactions and how to visualize them. I asked him to observe the polymerization process using the famous reaction-baking powder and superglue! In the pursue of the knowledge, I also asked him to fix the classroom wall and floor. The student is very delighted to learn. Thanks to the learning process, the cracks in the wall and floor are now GONE! Haiya, it is all sunshine and rainbows in STEM class.  

1. Baking powder/baking soda
2. Graphite powder
3. Superglue (Cyanoacrylate esters)
4. Spatula
5. Scissor
6. Paper Cardboard

Paperboard material is chosen because it is able to absorb the excess liquid from the superglue and the paper material can be easily recycled. Instructions:

Cut the cardboard into a rectangle 10 cm x 20 cm 

We have tried several ratios of graphite, baking powder, and baking soda. The best result came from (9:1) ratio of graphite powder with baking powder. With an increasing mass of the carbonates, the speed of polymerization skyrockets. We found that baking powder is better ingredient than baking soda. Baking powder and superglue gave a cement-like properties. We have tested it to attach two bricks together. It's like magic!

Clean the surface, and make sure it is dry. Gently pour 3-6 grams of cyanoacrylate superglue into the mixture of graphite and carbonates. Mix it thoroughly and immediately apply to the surface / hole. The composite will solidify within less than 30 seconds.

You have less than a minute to apply the composite to fill the cracks on the wall/floor. The composite will solidify and bind strongly to the surface. You can also apply a pure carbonate directly to the hole and drop the superglue into it. Fast polymerization and it is exothermic!

It’s bonding time! Student feels excited! Was this the ancient Egyptians’ technique to build the pyramids?!? We might solve the mystery here. Some students from the other classes saw the results and joined forces to do more experiments. One student commented:

‘’This is a useful reaction, we know several things now, its hot.. So it’s an exothermic reaction, definitively not an equilibrium! It produces some kinds of vapor.. probably steam and it is reacting very very fast.’’

Thank you for reading this.

Special thanks to Bryan Hartanto, Natascha, and Mr. Fielly Budiman.

We hope, this article will bring you happiness in learning Chemistry. Okay, Let’s sing this song together! Bring back the good ol’ days.