Abstract
Column fractionation for a small sample size or a large sample size of cis-polybutadiene has been studied. After optimizing fractionation conditions particularly suitable for a large sample size fractionation, one to 300 gramms of a sample of cis-polybutadiene were fractionated by a suitable column apparatus. A reversion of a degradation problem usually encountered in an incomplete column fractionation process was not observed in this experiment even at fractionation of larger sample sizes. Intrinsic viscosity distributions obtained from each fractionation experiment showed good agreement provided the maximum polymer concentration in the eluant was below 0.5 %. The breadths of molecular weight distributions of typical fractions thus obtained were fairly narrow (molecular weights ratio 1.1; measured by ultracentrifugation). The fractionation could be completed within several days for 300 gramms of the sample. The fractionation system offers a possibility of a supply of large quantity of narrow distribution polybutadienes to permit physical or technological studies as a function of molecular weight.
