Synthesis of Isotactic Polybutene-1 over Titanium-Magnesium Catalysts with Polydentate Phosphine Oxides As External Electron Donors

The polymerization of 1-butene over the TiCl4/MgCl2 (TMC) catalyst with the use of substituted phosphine oxides R n P(O)(CH2OR′)3 − n (R = alkyl, R′ = methyl or acyl, n = 0–2)—new external electron donors-has been investigated. The electron-donating (coordinating) centers in these compounds are the phosphoryl group (P=O) and the oxygen atoms of the substituents at the phosphorus atom. The dependence of the 1-butene polymerization activity of TMC on the nature of the substituents in the phosphine oxides has been studied. The microstructure, degree of crystallinity, molecular weight, and strain-strength characteristics of the synthesized polybutene-1 and the effect of hydrogen on these properties are reported. The most efficient external donor is Me2P(O)CH2OAc.