Synthesis of stereodiblock polyisoprene consisting of cis-1,4 and trans-1,4 sequences by using a neodymium catalyst: change of the stereospecificity triggered by an aluminum compound

Abstract

The first example of the synthesis of stereodiblock polyisoprene which consists of cis-1,4 and trans-1,4 sequences was achieved by using a neodymium catalyst. The stereospecificity was controlled by the ratio of Bu₂Mg and modified methylaluminoxane (MMAO), and by sequential addition of Bu₂Mg and MMAO, a geometrically well-defined stereodiblock polymer was obtained.