Effect of Catalyst Type on the Copolymerization of Styrene/1-Hexene and Exploring of Their Structural and Thermal Properties

Abstract

The effect of catalyst type on styrene/1-hexene copolymerization reactions was investigated. The copolymerization reactions were performed using conventional free radical polymerization, atom transfer radical polymerization (ATRP) and Ziegler-Natta polymerization methods. Copolymers containing different 1-hexene compositions were synthesized and characterized by 1H NMR, GPC and DSC methods. The monomer reactivity ratios for free radical copolymerization were calculated using linear methods and found to be r1 ~ 25 and r2 → 0 for styrene and 1-hexene, respectively. The increases of 1-hexene mole fraction in ATRP synthesized copolymers showed that CuCl/L promotes 1-hexene cross propagation significantly. Furthermore, 1-hexene cannot participate in self-propagation reaction. In the polymerization assisted by supported Ziegler-Natta catalyst, the conversion of the reaction was increased with mole fraction of 1-hexene in the feed, which indicated the higher reactivity of this monomer. Finally, the thermal properties of copolymers were studied by DSC.