Gowf, as the Scottish first called it, had humble beginnings in eastern Scotland as a game played with wooden balls and clubs (Mallon, 2011). Since its humble beginnings, golf has grown to be a sophisticated sport growing ever more so as researchers pump all of their expertise into the game in a quest to make the ideal ball.
The first modern golf ball consisted of a small, hard core wound with a long string of rubber and then coated with tree gum called gutta-percha (Mallon, 2011). Since then, many improvements have been made on golf balls to give them the perfect “feel” (i.e. a certain resilient, soft feel that golfers look for when their clubs make contact), but also great durability and wear and tear resistance. These two qualities tend to be mutually exclusive in a single material; however, scientists have developed balls with several layers, each layer addressing a specific need that the ball has.
Researchers have targeted polymers, a long molecular chain made of many smaller subunit molecules linked together, as the best materials for golf balls. This is because polymers are very flexible – by changing even one atom in the subunit or twisting the subunit slightly, a polymer can go from being used for the hard golf ball cover to the more elastic inner layer.
Figure 1: A – chemical structure of natural rubber, B – chemical structure of gutta-percha
An example of how a slight difference between polymers makes a big difference in the ball is seen between gutta-percha and natural rubber, as seen in Figure 1 (Goodman, 1974; Yikmis,Steinbüchel, 2012). The lower structure is gutta-percha, which was replaced in golf history by natural rubber, the upper structure. As can be seen, rubber has more kinks in its structure, making it a better molecular spring than the more rigid gutta-percha. This spring-like quality made the ball compress more when struck, thus transferring more energy to the ball’s flight when the molecules “pushed off” the club.
Golf balls have other important pieces to them, such as the cover. The cover of a golf ball must be able to withstand up to 10,000 N (Penner, 2003) of force without cracking and also be able to take repeated hits without wearing down. The entire ball must be able to snap back into its original shape without any damage to itself or its properties from the momentary deformation that occurs when it is hit with the club. The ideal ball would have a perfect transfer of energy between the club and the ball, so that none of the golfer’s force is wasted.
How can a perfect ball be manufactured? A perfect ball would be easy to manufacture, being made from polymers that easily release from their mold, thus preventing damage to the ball if it had to be pried from its mold. The best golf balls to date are multi-layer balls, which have four layers devoted to a specific purpose: middle layers that are compressible and elastic, the cover that is hard and resilient, and an inner core that is rigid to maintain form (Giffin, 2002). Even with such high-tech polymer balls, other challenges remain: can scientists develop a polymer to do all that has been required of it previously and prevent moisture from seeping into the ball and compromising its integrity?
By: Jessica Egan, University of Utah
Jessica Egan began her love of chemistry under her mom’s direction with homeschool experiments in middle school and then up into high school through her high school chemistry teacher. She pursued a chemistry and art double major at Hillsdale College and decided to continue her chemical education by attending graduate school at the U. She has recently graduated with a M.S. from the U in Analytical Chemistry and is looking for a career in industry.