Microstructure and Glass-Transition Temperature of Novel Sn-SIBR

A novel Tin-functionalized integrated rubber of styrene-isoprene-butadiene (St-Ip-Bd) tri-copolymer (Sn-SIBR) was prepared by anionic polymerization using self-made tin-containing organolithium (SnLi) as initiator, tetrahydrofuran (THF) as polar modifier, and cyclohexane as solvent. The microstructure and the glass-transition temperature (Tg) of tri-copolymers were characterized by 1H NMR and differential scanning calorimetry (DSC), respectively. The result shows that the non-1,4-structure content and the Tg of tri-copolymers increased with the increase of THF dosage and the initiator concentration or the decrease of polymerization temperature. We also obtained the relationships between the ln(T/Li)( THF/ SnLi, mole ratio) and the non-1,4-structure content, the non-1,4-structure content and the Tg of copolymers, respectively.