Polymerization of isoprene inn‐heptane with triethylaluminum–titanium tetrachloride catalyst. I. Effect of Al/Ti ratio on stereoregularity, conversion, molecular weight, and molecular weight distribution

摘要

AbstractThe influence of the Al/Ti ratio of the heterogeneous Ziegler–Natta catalyst system AlEt3–TiCl4on the isoprene polymerization inn‐heptane at 30°C in a bench scale reactor was investigated. Each batch run consisted of 50 mL isoprene, 200 mLn‐heptane with 0.45 and 0.5g catalyst. Conversion of isoprene and molecular weights of polyisoprene increased with increasing Al/Ti ratio, reaching their maxima values at 1.0 and 1.2, respectively. Conversion and molecular weights decreased remarkably at a higher ratio of Al/Ti. As this ratio decreases from the value of 1.2 to 0.4, thecis1,4 content in polyisoprene decreased from 97 to 25. When the ratio of Al/Ti increased from 1.2 to 2.2 thecis‐1,4 structure of polyisoprene decreased from