Model linear and star-shaped polyisoprenes with phosphatidylcholine analogous end-groups. Synthesis and association behavior in cyclohexane

David Charalabidis, Marinos Pitsikalis, Nikos Hadjichristidis*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

12 Scopus citations

Abstract

Semitelechelic (ω-), telechelic (α,ω-), as well as 3- and 12-arm star polyisoprenes (PI), end-functionalized with the same dimethylamino group, were synthesized by aniomic polymenzation high vacuum techniques, using 3-dimethylaminopropyllithium as initiator and chlorosilanes as linking agents. The dimethylamino groups were transformed to phosphatidylcholine analogues through reaction with 2-ethoxy-2-oxo-1,3,2-dioxaphospholane. The association behavior of the phosphoro-zwitterionic PI (PZw-PI) was studied in cyclohexane by low angle laser light scattering, viscometry, and dynamic light scattering. The linear PZw-PIs present relatively low weight-average degree of association (Nw: 2-6), as compared with the corresponding sulfozwitterionic PI (Nw: 10-45). The Nw values decrease with increasing molecular weight of the PI. In the case of the star PZw-PI, the multiple intermolecular associations lead to the formation of gels, which break down by addition of a small amount of 1-heptanol. In very dilute solutions and for high arm molecular weight stars, intramolecular dominates over intermolecular association.

Original languageEnglish (US)
Pages (from-to)2132-2141
Number of pages10
JournalMacromolecular Chemistry and Physics
Volume203
Issue number14
DOIs
StatePublished - Oct 18 2002
Externally publishedYes

Keywords

  • 3-dimethylaminopropyllithium
  • Anionic polymerization
  • Chlorosilanes
  • Cyclohexane
  • End-fun00000000ctionalized polyisoprenes
  • Phosphatidylcholine analogous groups
  • Self-assembly

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Polymers and Plastics
  • Materials Chemistry

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