polymethylene
/ˌpɒlɪˈmɛθɪliːn/Chemistry
noun
Originally: any of the series of saturated cyclic hydrocarbons with the formula (CH2)n; = naphthene. Later: a compound, group, or polymeric structure which consists of or contains a chain of methylene groups, —(CH2)n.
Origin
Late 19th century; earliest use found in Journal of the Chemical Society. From poly- + methylene.