Isotactic poly(butene-1) (

i

PB) with spherical morphology was synthesized successfully with bulk precipitation polymerization without post-treatment of the products. The bulk precipitation polymerization process made it possible for

i

PB to be used as general plastic due to the acceptable decreased cost compared with the solution polymerization process. The influence of catalyst residues on the aging and thermal stability of

i

PB synthesized by bulk precipitation polymerization method was investigated by gel permeation chromatography

mechanical performance testing

thermogravimetric analysis and infrared spectroscopic analysis. Commercial

i

PB and the lab-made

i

PB with varied catalyst residue contents were studied. The results demonstrated that the catalyst residues played an important role in the aging process of the

i

PB. A possible mechanism of aging promotion by catalyst residues was proposed.