Hydrolysis and Condensation Coupling of (Trimethoxysilyl)phenyl-Terminated Polystyrene Macromonomers

T. H. Mourey, S. M. Miller, J. A. Wesson, Timothy Edward Long, L. W. Kelts

Research output: Contribution to journalArticlepeer-review

32 Citations (Scopus)

Abstract

Anionically grown monofunctional polystyrene macromonomers are coupled through the hydrolysis and condensation of trimethoxysilyl end groups. Hydrolysis is initiated by adding acidified water to a tetrahydrofuran solution of the macromonomer. Condensation is facilitated by evaporating the solvent and heating the polymer under vacuum above the glass transition temperature. The macromonomers couple to form high molecular weight polymers and reach a finite size, beyond which further growth is inhibited. The final products are completely soluble star-shaped polymers, which are characterized by size-exclusion chromatography with molecular weight sensitive detectors. The molecular weight distributions of the stars are surprisingly narrow, although there are definitely mixtures of stars with different numbers of arms. The average number of arms in a star decreases as the molecular weight of the macromonomer increases. The final, limiting structures of the stars can be explained by the free energy changes associated with the number and length of arms. The results strongly suggest that the prevalent mode of growth at later stages of condensation becomes addition of macromonomer to stars, rather than addition of stars to stars. Studying the condensation coupling of the macromonomers provides understanding for more complicated networkforming systems; the technique also provides a unique method for synthesizing star-shaped polymers that has several advantages over other synthetic methods.

Original languageEnglish
Pages (from-to)45-52
Number of pages8
JournalMacromolecules
Volume25
Issue number1
DOIs
Publication statusPublished - 1992 Jan 1
Externally publishedYes

ASJC Scopus subject areas

  • Organic Chemistry
  • Polymers and Plastics
  • Inorganic Chemistry
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Hydrolysis and Condensation Coupling of (Trimethoxysilyl)phenyl-Terminated Polystyrene Macromonomers'. Together they form a unique fingerprint.

Cite this