July 8, 2014
The Science Of A Soccer Ball
So who out there has been following the World Cup?
Well, for those that have been, as well as those, like me, who only occasionally tune in to see how the various teams have been doing — as well as anyone who just likes knowing how things work – have you ever given a thought to the science that goes into sports like this one? After all, science is in everything, including soccer — or “football,” if you prefer, but I think some of my friends would murder me if I tried to argue soccer as football – there is a great deal of science that goes into the ball.
A soccer ball is made up of three key parts: the outer covering, the lining, and the bladder. The covering is made up of polyurethane panels, normally 32, that are heated until they bond together. What is polyurethane? Polyurethane is a polymer, which is a long molecule that that is made up of several different molecules, allowing them to take on various properties. Polyurethane is a common polymer that you can find in everyday household items such as furniture, band-aids/adhesive strips, and even in your shoes. The polyurethane used in soccer balls is made up of isocyantes and polyols, which help keep the covering from absorbing water, making the ball heavier and denser while playing. By using polyurethane, the soccer ball is kept much lighter than it would be if it were made out of leather.
The lining, which is made up of several layers, is also made up of polymers. These polymers are called polyamides. Polyamides are macromolecules with repeating units that are linked together by amide bonds. These can occur both naturally and artificially, though the soccer ball uses artificial polyamides. Nylon is the most commonly known polyamide. Commonly, polyamides are used in textiles, automotive engineering, carpets, and sportswear — such as in this case. It is used here to improve the bounce of the ball, as well as its overall strength and resilience. In this way, it keeps the ball from bursting after too many kicks.
Finally, we have the bladder, which is made of butyl rubber. First used in tire inner tubes, butyl rubber is a synthetic rubber, a copolymer made up of isobutylene and isoprene. Butyl rubber is commonly used in things like adhesives, agricultural chemicals, electrical fluids, lubricants, personal care products, and even in chewing gum. Now, this not universal. While true of the balls used for the World Cup, some soccer balls have a latex bladder. While latex bladders provide a great deal more surface tension, soccer ball bladders made up of butyl rubber hold the air in for much longer. In addition, butyl rubber is also in the valve used to air up the balls.
And there you have it, the science behind the soccer ball.
Interested in hearing more about the science of the soccer ball? Take a look here. For more really neat ways that chemistry influences our modern life, check out Compound Interests at compoundchem.com.
And for all those soccer fans out there, I hope you enjoy the rest of the World Cup.
Image Credit: Thinkstock