The microstructure of polydienes directly affects the elasticity

crystallinity

heat resistance

hydrogenation

damping and other properties of the product. In order to explore the influence of tetrahydrofuranyl [N

O]-chelated polar-additives (PA) on microstructure of anionic polymerization of conjugated dienes

four high-efficient PAs including

N

N

-dimethyl-tetrahydrofurfuralamide (DMTHFA)

N

-tetrahydrofuromorpholine (THFM)

N

-tetrahydrofuropipine (THFHP) and

N

-tetrahy- drofurfuryl pyrrole (THFP) were selected to coinitiate butadiene (BD)

isoprene (IP) and 1

3-pentadiene (PD) polymerization with

n

-BuLi. It is also compared with tetrahydrofuran (THF) commonly used in industry. The results based on

1

H-NMR data showed that: (1) all PAs had highly efficient regulation (molar ratio

PA/Li≤4.0)

which can be used for the production of medium and high branched polybutadiene and polyisoprene rubber. However

the 1

2-polypentadiene can only be regulated in the range of 20%~38% due to its special molecular conformation; (2) under the effect of DMTHFA and THFM

the branched structure of polybutadiene and polyisoprene decreased with increasing temperature

but the 1

2-polypentadiene increased slightly. Interestingly

the DMTHFA is not sensitive to temperature; (3) the amplification experiment showed that PA can significantly increase the polymerization rate and the regulation ability is better than that of the ether regulator used in industry equipment. Moreover

the PA had positive effect on the hydrogenation degree of the SBS

which has the prospect of industrialization.