STRUCTURAL CHARACTERIZATION OF SYNDIOTACTIC 1,2-POLY(4-METHYL-1,3-PENTADIENE)

4-Methyl-1,3-pentadiene was polymerized with the MAO/CpTiCl(3) (MAO: m ethylaluminoxane, Cp: cyclopentadienyl) system to yield a highly stere oregular syndiotactic 1,2-polymer. Fiber diffraction patterns indicate two crystalline modifications: a major one with a repeat of 11.73 Ang strom and minor amounts of a zig-zag planar polymorph (axial repeat 5. 05 Angstrom). Energy calculations account for three nearly isoenergeti c conformations: the more stable one, with repeat of 11.65 Angstrom, i s (T(6)G(2)T(2)G(2)) analogous to the one recently reported for syndio tactic poly(propylene) (Chatani et al., 1991).