It's used in all kinds of products, including adhesives, fibre optics, sealants, cling film, paper, fuel, explosives, sporting equipment, roofing, bottle stoppers, and tires.
These chemicals-widely used in the middle decades of the 20th century to manufacture electrical insulation, coolants, sealants and plasticisers-often ended up dumped in lakes, rivers and coastal waters.
Shampoos also get fancy with their polymers—some add volume or weight or increase the shine and feel, while others protect from things like UV rays—but, in essence, they all work like waterproofing sealant on a deck.