! Effect of L-menthol chain-end on the optical rotation, chirality, tacticity and thermal properties of polystyrene prepared by ATRP and polyvinylacetates prepared by RAFT polymerization: A molecular weight dependence study

Two series of L-menthol-tagged homopolymers: one polystyrenes (PSt) and the other polyvinylacetates (PVAc) having different molecular weights have been synthesized via ATRP of styrene, and RAFT polymerization of vinyl acetate, respectively. Optical rotation study has established the magnitude of the optical rotation value for the both polymer series has been found decreasing exponentially with the increase of their molecular weights. CD study has revealed an exponential decrease in the molar ellipiticity values at 235 nm with the increase in the DPs of polymers in both the polymer systems. Formed PSts and PVAcs are atactic and slightly syndiotactic, respectively. With increase in the chain length of the polymers, glass-transition temperature (T-g) values have been found increasing exponentially in both systems. Therefore, living radical polymerization using suitable ATRP initiator or, RAFT agent containing suitable chiral moiety can be useful in inducing chirality in polymers up to high chain length.