It’s pretty obvious what’s going to happen if you drop a watermelon from a 45 meters (148 feet) high tower. It would fall fast and create a large fruity mess at the bottom. In this video by Veritasium however, they showed that if the watermelon is sprayed by a certain black polymer coating, wait for it to dry, and drop it off the tower, it would break. It bounces!
What?! How is that possible?
Here’s the whole video footage.
Source: YouTube, Veritasium
As you witnessed in the video, even an axe couldn’t break the coating apart! The team finally managed to open the spray-coated watermelon by using a table saw. There, they found out that the casing of watermelon was still amazingly whole and intact. Unfortunately, the innards of the fruit were all turned into slushy.
The fall had a speed of 100 km/hr or 62 mph! How could a simple coated watermelon survive that kind of fall?! Well, obviously, it was all in that special coating. So what was in there?
It’s a spray-on truck bedliner called Line-X. It is the same coating that is used to line the walls of the Pentagon to prevent exterior explosions from launching shrapnel inside the building, it is also used to create bullet proof vests, so that it would contain bullet fragments that could cause serious injury.
Source: Peaceriverlinex
Line-X is made up of two ingredients, named ingredient A and B. A is made up of a molecule named Diphenylmethane-4,4′-diisocyanate, or MDI for short. It is a molecule that is very reactive at its ends. On the other hand, B is the plasticizing agent in the mixture.
When these two molecules mix, they bond together within just seconds and form a longer molecule known as polyurea. These tangled molecules are responsible for the intense strength of Line-X, as well as its flexibility, since they can be stretched and snap back into place.
The video shows that the mixture of the molecules make the coating incredibly hot. This is because the binding of the molecules releases so much energy and comes out in the form of heat. When they applied the coating onto a piece of paper, it was still possible to pull it apart when it was still hot. Once the paper cooled down, the paper could be ripped apart!
Can you imagine this coating to be used on different items such as our smartphones and gadgets?
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