Most modern chewing gum is made from synthetic rubber used in tire inner tubes.

Before the 1940s, chewing gum was primarily made from chicle, a natural latex sap harvested from the sapodilla tree in Central America. During World War II, demand for gum skyrocketed as it was included in military rations to help soldiers relieve stress and keep their mouths moist. This surge in demand, combined with supply chain disruptions, forced chemists to find a reliable alternative to natural resins.The solution was polyisobutylene, a synthetic rubber also used to manufacture inner tubes for tires and liners for sports balls. Polyisobutylene is a vinyl polymer and a primary component of butyl rubber. It provides the unique viscoelastic properties that allow gum to be stretched and chewed repeatedly without breaking down or dissolving in the mouth. This synthetic base is chemically inert and does not react with saliva, ensuring a consistent texture throughout the chewing experience.Today, the 'gum base' listed on ingredient labels is a proprietary blend of elastomers, plasticizers, and waxes. While the FDA classifies these synthetic rubbers as 'food grade,' they are essentially the same polymers used in industrial adhesives and sealants. Companies like Goodyear and ExxonMobil are major producers of these polymers. This shift from natural chicle to petroleum-derived synthetics allowed the industry to scale globally while significantly reducing production costs.