Aspects of the Synthesis of Poly(styrene-b-isobutylene-b-styrene) Block-Copolymers Using Living Carbocationic Polymerization
Document Type
Article
Publication Date
12-6-1993
Department
Polymers and High Performance Materials
Abstract
The effect of the time of styrene addition on the composition of poly(styrene-isobutylene-styrene) (PS-PIB-PS) block copolymers synthesized using a dicumyl chloride/TiCl4/pyridine initiating system and the sequential addition of monomers was investigated at -800-degrees-C. It was found that the addition of styrene at an isobutylene (IB) reaction time significantly exceeding the time necessary for complete IB consumption results in contamination of the material with a substantial amount of homo-PS. Conversely, the addition of styrene to PIB chains formed under conditions of intermediate IB conversion resulted in a very slow buildup in molecular weight after the addition of styrene. This retardation of the rate after the addition of styrene was proven to be the result of a random copolymerization between styrene and unreacted IB. It was also found that the addition of the proton trap 2,6-di-tert-butylpyridine resulted in a narrowing of product polymer molecular weight distribution.
Publication Title
Macromolecules
Volume
26
Issue
25
First Page
6727
Last Page
6733
Recommended Citation
Storey, R. F.,
Chisholm, B. J.
(1993). Aspects of the Synthesis of Poly(styrene-b-isobutylene-b-styrene) Block-Copolymers Using Living Carbocationic Polymerization. Macromolecules, 26(25), 6727-6733.
Available at: https://aquila.usm.edu/fac_pubs/6700