Synthesis of High 1,2-Microstructure POLY(1,3-BUTADIENE) Using a Biobased Lewis Base

High 1,2-microstructure poly(1,3-butadiene)s were prepared using the biobased Lewis base, isosorbide dimethyl ether (IDE) and different initiators (sec-BuLi or n-BuLi) in cyclohexane at various temperatures (30, 50, and 70 ^oC). The amount of microstructure of poly(1,3-butadiene) using IDE ([base]/[Li]=1/1; 65%) is comparable with DIPIP (1,2-bispiperidinoethane; 68%) but lower than that using  DIDIOX [2,2’-Bis(4,4,6-trimethyl-1,3-dioxane); 80%] at 50 ^oC. Less temperature dependence for the amount of 1,2-microstructure was found using IDE as an additive in comparison to that using DIPIP and DIDIOX. The existence of a high molecular weight shoulder suggests that chain end decomposition occurred during the polymerization. The molecular weight control could be improved using the less reactive n-BuLi as initiator.