The gels were copolymerized with substrates - 0.002 % hyaluronic acid or 0.1 % gelatin.
Molecules with different lengths and differing axial assembly parameters are extremely unlikely to copolymerize into viable intermediate filaments and, indeed, this seems to be the case.
As opposed to metallocenes, they can also randomly copolymerize ethylene with polar comonomers such as methyl acrylate.
In presence of a bismaleimide the double bond of the maleimide group can copolymerize with the cyano groups to heterocyclic 6-membered aromatic ring structures with two nitrogen atoms (pyrimidines).
