Crystallizable Polyisoprene under Strain Obtained by Nd-based Catalyst
The conventional Ziegler-Natta catalyst composed of neodymium versatate (Nd(vers)3), alkylaluminum (Al(i-Bu)2H or Al(i-Bu)3) and diisobutylaluminum chloride (Al(i-Bu)2Cl) was examined in isoprene polymerization. The polymer with narrow molecular weight distribution (Mw/Mn < 3) can be obtained by controlling Al(i-Bu)2H amounts and component addition order. While, polyisoprene with high cis-1,4 content (> 96%), high molecular weight (> 100×104) and narrow molecular weight distribution (Mw/Mn < 2.2) is synthesized by using Al(i-Bu)3 as cocatalyst. In the meantime, the obtained polymer has crystallization behavior under strain.