Synthesis of High-Trans 1, 4-Butadiene/Isoprene Copolymers by Anionic Polymerization Using Barium Salts

摘要

High trans-1,4-butadiene-isoprene copolymer (TBIR) is an ideal material for high performa nce radial tires due to its low heat build-up, outstanding fatigue durability, good wear characteristics and low temperature performance. High trans-1,4-butadiene-isoprene copolymer (TBIR), initiated by n-butyllithium (n-BuLi) ,triisobutyl aluminium [Al(I-Bu)3] and an organic barium salt, was synthesized and characterized. Thymol barium (BAT) was synthesized via thymol and barium hydroxide, the preparation of barium salt of di(ethylene glycol) ethyl ether (BaDEGEE) was similar to BAT. Kinetics behaviors of the copolymerization were researched through dilatometer method. Crystallization Behaviors and Glass transition temperature (Tg) were measured by Differential Scanning Calorimetry (DSC). The glass-transition temperatures (Tg) were -8 4 °Cthereabout. An analysis using IR spectra and 1 H-NMR spectra indicated that the TBIR was belong to high-trans-1,4-configuration polymers. The chemical structure of these copolymers was characterized by a high-trans 1,4-configuration: the trans 1,4-content of Ip units was greater than 85% ,and the trans 1,4-content of Bd units was greater than 70%.