from 0 to 50% by weight, based on the total amount of monomers, of a monocyclic olefin of the formula VII in which n is a number from 2 to 10, and from 70 to 0.1% by weight, based on the total amount of monomers, of at least one acyclic olefin of the formula VIII in which R9, R10, R11 and R12 are identical or different and are a hydrogen atom or a C1-C8-alkyl radical or a C6-C16-aryl radical, at t