Study on unsaturated structure and tacticity of poly1-hexene and new copolymer of 1-hexene/5-hexene-1-ol prepared by metallocene catalyst

• 1-hexene homopolymerization and 1-hexene/5-hexene-1-ol copolymerization were conducted using Cp2ZrCl2/MAO catalytic system.
• Tacticity and termination reaction mechanisms of (co)polymerization were investigated by NMR analyses.
• Results showed that homopoly1-hexene chains have vinylidene (Vd, resulted from 1,2-inserted chain-end) end structure.
• In the copolymer, both Vd and di-substituted vinylene (2Vn, resulted from 2,1-inserted mechanism) chain ends have been seen.

1-hexene homopolymerization and 1-hexene/5-hexene-1-ol copolymerization were conducted using metallocene, Cp2ZrCl2, catalyst with methylaluminoxane (MAO) as activating agent. IR and 13C NMR analyses of the resulting (co)polymers was done to confirm incorporation of functional monomer to the poly1-hexene backbone.13C-and 1H NMR analyses were carried out to identify the tacticity and termination reaction mechanisms of (co)polymerization and study unsaturated structures of the (co)polymers. Our results showed that this catalytic system produces homopolymer chains with, vinylidene (CH2=CRR′, Vd, resulted from 1,2-inserted chain-end) end structure and with 74% isotacticity; while that in the copolymer both Vd (resulted from 1,2-inserted mechanism, 70%) and di-substituted vinylene (2Vn, resulted from 2,1-inserted mechanism, 30%) chain ends have been seen.

1-hexene homopolymerization and 1-hexene/5-hexene-1-ol copolymerization were conducted using Cp2ZrCl2/MAO catalytic system. After (co)polymers synthesis, the tacticity and termination reaction mechanisms of (co)polymerization were investigated by NMR analyses. Results showed that, in coordination polymerizations, beside catalyst, monomer type and reaction conditions are among basic parameters in determining mechanism of termination reactions.Figure optionsDownload as PowerPoint slide