The low molecular weight fractions and volatile components of the trans-butadiene-co-isoprene copolymer rubber (TBIR)

which synthesized by using the MgCl

2

supported TiCl

4

catalyst system

are collected by using constant temperature solvent fractionation and variable temperature gas phase collection methods. The collected components are characterized by

1

H nuclear magnetic resonance (

1

H-NMR)

gel permeation chromatography (GPC) and gas chromatography/mass spectrometry (GC-MS). The results show that the content of ether soluble fraction is about 50% (wt). The ether soluble fraction is composed of high trans-butadiene-co-isoprene copolymers with lower molecular weight and a small amount of butadiene-isoprene dimer and oligomer. The content of acetone soluble component is about 7.6% (wt). The acetone soluble component is composed of isoprene-butadiene dimers and/or copolymers with the weight average molecular weight about several hundreds. The as-obtained copolymers and dimmers may generate during the copolymerization process by the triisobutyl aluminium cocatalyst. The volatile component obtained by the low temperature gas phase collection is mainly isoprene monomer residual in TBIR. With the increasing of the gas phase collection temperature

there appears butadiene-isoprene dimer and the content of butadiene-isoprene dimer increases as while as the content of isoprene in the volatile component decreases.