L. Porri, M. Gallazzi
Aug 1, 1966
Citations
0
Influential Citations
21
Citations
Journal
European Polymer Journal
Abstract
Abstract 4-Methyl-1,3-pentadiene has been polymerized by heterogeneous catalysts from Al(C 2 H 5 ) 3 and either TiCl 4 , TiCl 3 or VCI 3 , to give polymers having almost exclusively 1,2 units, and showing crystallinity attributable to 1,2 isotactic sequences. Homogeneous systems from Al(C 2 H 5 ) 3 and either a titanium tetraalkoxide or a vanadyl trialkoxide yield from the same monomer polymers, which, although almost 100 per cent 1,2, are amorphous by X-ray examination. Infra-red and X-ray analyses indicate that the 1,2 isotactic polymers of 4-methyl-1,3-pentadiene exist in two crystalline modifications. The different results obtained from 4-methyl-1,3-pentadiene as compared with butadiene in the polymerization by each of the above systems, are interpreted on the basis of steric effects caused by the methyl groups on position 4.