From naturally occurring beta-methylstyrenes, such as anethole and isoeugenol, a bio-based copolymer was prepared by the controlled cationic copolymerization with the alcohol/BF3OEt2 initiating system in an aqueous solvent. The copolymerizations with p-methoxystyrene proceeded in a living fashion, in which the molecular weights and molecular weight distributions of the resulting copolymers were controlled. Specifically, isoeugenol can be copolymerized without protection of the phenolic moiety to give an almost alternating copolymer, which can be regarded as a well-defined linear lignin analogue with the functional 4-hydroxy-3-methoxyphenyl groups.