Diblock copolymer ethylene-syndiotactic styrene

The one-pot synthesis of ethylene-styrene (ES) copolymers, where an isotactic polystyrene sequence is jointed to an alternating ES sequence, has been recently obtained by the quasi-living polymerization at low temperature using the catalyst zirconocene rac-methylenebis(1-indenyl)zirconium dichloride activated by methylaluminoxane (MAO) (1). Keeping in the mind the idea of makingnew ES architectures copolymer, we have carried out the synthesis, through the living polymerization at low temperature, of a ethylene-styrene diblock copolymer with unprecedented structure, containing stereoregular polystyrene blocks. The key of the achievement is the homogenous polyinsertion catalysis by CpTiCl3 at 0 °C combined with MAO and a judicious choice of monomers feed composition. 13C nuclear magnetic resonance analysis of the boiling toluene soluble fraction (fig.) indicates the contemporary presence of syndiotacticstyrene sequence (sPS) and polyethylene sequence. The length of the ethylene sequence, estimated by the NMR resonances, increases with the growth of the ethylene concentration in the monomer feed composition. The atomic force microscopy (AFM) techniques shows how these materials in the solid state organize themselves into nanostructures depending on the comonomers composition. References 1. N. Galdi, A. Buonerba, P. Oliva and L. Oliva, Polym. Chem., 2014, 5, 3045-305.