Question: Boots that rise to the knee and were originally made of leather, can be made of a synthetic rubber that exhibits good chemical stability, and is produced by the polymerization of what? 
Sentence (from "Neoprene"): Neoprene is sold either as solid rubber or in latex form, and is used in a wide variety of applications, such as laptop sleeves, orthopedic braces (wrist, knee, etc.), electrical insulation, liquid and sheet applied elastomeric membranes or flashings, and automotive fan belts.
Relevant evidence: No