Abstract
Abstract o-Methoxystyrene was polymerized under various conditions with BF3 O(C2H5)2, SnC14, or A1(C2H5)Cl2 catalyst. The effect of polymerization conditions on the steric structure of poly(o-methoxy-styrene) was studied by NMR spectra of the methoxyl protons, and has been tentatively assigned to the triad tacticity of the polymer. Highly stereoregular polymers were not obtained by these catalysts. The tacticity of polymers was independent of the polarity of solvents, as observed in the cationic polymerization of α-methylstyrene. This behavior was completely different from the cationic polymerization of vinyl ethers. It was found that the heterotactic fraction increased with decreasing polymerization temperature upon polymerization in toluene solution. The fraction of the triad tacticity calculated from Bovey's equation coincided with the experimental results. This fact shows that the steric structure of the addition monomer is determined only by the growing chain end unit and that there is no penultimate...
Published Version
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