Model Mono-, Di-, and Tri-ω-Functionalized Three-Arm Star Polybutadienes. Synthesis and Association in Dilute Solutions by Membrane Osmometry and Static Light Scattering

Marinos Pitsikalis, Nikolaos Hadjichristidis*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

38 Scopus citations

Abstract

Three-arm polybutadienes with one, two, and three functional end groups were prepared by anionic polymerization using [3-(dimethylamino)propyl]lithium and sec-butyllithium as initiators and methyltrichlorosilane as linking agent. Characterization carried out on the dimethylamine-capped polymers by size exclusion chromatography (SEC), in THF, low-angle laser light scattering (LALLS) in THF, and membrane osmometry (MO) in toluene indicates a high degree of molecular and structural homogeneity. The 1,2 content, determined by NMR spectroscopy, of the arms having the functional groups was higher (12-32%) than that of the arms without the functional groups (7-10%), owing to the tertiary amine group of the initiator. The dimethylamine end groups were transformed to the highly polar sulfozwitterionic ones by reaction with cyclopropanesultone. Association of the different ω-functionalized star polybutadienes was studied in dilute solutions of cyclohexane by MO and LALLS. It was found that although the dimethylamine-capped polybutadienes do not associate, the corresponding zwitterionic species associate strongly in this solvent. At fixed molecular weight of the arms, the degree of association increases with decreasing number of functional groups and, for the same number of functional groups, with decreasing molecular weight of the arms. The trifunctional species form gels at concentrations needed for MO experiments. Comparison with linear ω-zwitterionic polybutadienes in cyclohexane shows that the stars associate less strongly, maybe due to the sterically hindered star structure (monofunctional species) and to intramolecular interactions (di- and trifunctional species).

Original languageEnglish (US)
Pages (from-to)3904-3910
Number of pages7
JournalMacromolecules
Volume28
Issue number11
DOIs
StatePublished - May 1 1995

ASJC Scopus subject areas

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

Fingerprint

Dive into the research topics of 'Model Mono-, Di-, and Tri-ω-Functionalized Three-Arm Star Polybutadienes. Synthesis and Association in Dilute Solutions by Membrane Osmometry and Static Light Scattering'. Together they form a unique fingerprint.

Cite this