The free-radical terpolymerization of maleic anhydride (MSA), isobutyl
vinyl ether (VIBE) and anethol (ANE) at 60 degrees C is described. Th
ese three monomers do not homopolymerize under the conditions used. Bi
nary copolymers are only obtained from MSA and one of the two investig
ated donor monomers, whereas the binary copolymerization of VIBE with
ANE is not possible. In all terpolymers from these three non-homopolym
erizable monomers the MSA content amounts to about 50 mol-%; VIBE is a
bout twice as reactive as ANF. The terpolymerization can formally also
be described under the assumption that two binary complexes (MSA/ANE
(I) and MSA/VIBE (II)) are copolymerized. For this case the reactivity
ratios r(I) = 0,9 and r(II) = 1,7 are obtained.