Hydrodynamic characteristics of branched polystyrenes with varying content of a highly branched fraction

• Published in: Polymer science. Series A, Chemistry, physics Vol. 59; no. 5; pp. 613 - 623
• Main Authors: Kurochkin, S. A., Makhonina, L. I., Vasil’ev, S. G., Perepelitsina, E. O., Zabrodin, V. A., Bubnova, M. L., Volkov, V. I., Grachev, V. P.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01-09-2017
• Subjects: Chemistry; Chemistry and Materials Science; Polymer Sciences; Solutions
• ISSN: 0965-545X; 1555-6107
• DOI: 10.1134/S0965545X17050078

The branched polymers containing different amounts of the highly branched fraction are synthesized by the radical copolymerization of styrene and divinylbenzene under conditions of the reversible inhibition by 2,2,6,6-tetramethylpiperidine-1-oxyl. The branched polystyrenes are studied by size-exclusion chromatography combined with static light scattering, viscometry, and pulsed-field gradient nuclear magnetic resonance. The branched polymers prepared by living radical polymerization (in the presence of 2,2,6,6-tetramethylpiperidine-1-oxyl) feature reduced intrinsic viscosities and increased self-diffusion coefficients compared with their linear analogs. As the content of the highly branched fraction in the synthesized polymers grows, the Zimm contraction factor in toluene solution decreases to
g
′ = 0.13. The Kuhn-Mark-Houwink parameters for these polymers in toluene solution (
a
= 0.43) confirm the nonlinear architecture of macromolecules.