Natural Degradation of Polymers

Polymers are a broad class of materials which are made from repeating units of smaller molecules called monomers. Polymers can be natural in origin, such as the lignin of tree branches, the starches of homemade bread, or the chitin of lobster shells. Other polymers are called synthetic, because they are made by humans from naturally-occurring materials. Examples include polyesters used in clothing, polystyrene used in home insulation, and silicones used in personal care and other products. Polymers are useful because of their strength and durability in many applications. However, after the useful life of a polymer is over, society desires that it degrade in the environment back to natural materials. This fact sheet first reviews the natural degradation of a wide variety of polymers, and then shows how the degradation of silicone polymers follows the same pattern.