Boots that rise to the knee and were originally made of leather, can be made of a synthetic rubber that exhibits good chemical stability, and is produced by the polymerization of what? 
Knee-high boot:  Originally made of leather, versions made of a synthetic rubber (PVC, Neoprene, etc.), they are used by fishermen, dairy workers, stable hands, duck hunters, clammers, etc. to protect the feet from water, mud, manure, etc. and to provide traction on slippery surfaces. Neoprene: Neoprene or polychloroprene is a family of synthetic rubbers that are produced by polymerization of chloroprene. Neoprene:  Neoprene exhibits good chemical stability and maintains flexibility over a wide temperature range.
i don't know