Polymer conformation and viscometric behaviour - 6. Synthesis, characterization and chain flexibility of (phenyl methacrylate-co-menthyl methacrylate) copolymers

Phenyl methacrylate-co-Menthyl methacrylate copolymers of different compositions were synthetized by radical polymerization in benzene at 298°K. Copolymers from three different compositions were fractionated by solubility. Number average molecular weights -Mn were obtained by osmometric measurements. The Mark-Houwink-Sakurada (MHS) equations were established in benzene at 298°K and the unperturbed dimensions determined by using the Stockmayer-Fixman extrapolation. From these results, the rigidity parameter σ was determined. The results show that the rigidity of the copolymers increase when the menthyl methacrylate content increase, and this is discussed in terms of specific interactions between the different units of the chain. The influence of the nature of the side group and their steric hindrance to rotation is also discussed.