Michael addition for crosslinking of poly(caprolactone)s

Gozde Ozturk, Timothy Edward Long

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

Poly(caprolactone) (PCL) networks have received significant attention in the literature because of many emerging potential applications as biodegradable materials. In this study, the Michael addition reaction was used for the first time to synthesize biodegradable networks using crosslinking of acetoacetate-functionalized PCL (PCL bisAcAc) oligomers with neopentyl glycol diacrylate. Hydroxyl-terminated PCL telechelic oligomers with number-average molecular weights ranging from 1000 to 4000 g/mol were quantitatively functionalized with acetoacetate groups using transacetoacetylation. In addition to difunctional PCL oligomers, hydroxyl-terminated trifunctional star-shaped PCL oligomers were functionalized with acetoacetate groups. Derivatization of the terminal hydroxyl groups with acetoacetate groups was confirmed using FTIR spectroscopy, 1H NMR spectroscopy, mass spectrometry, and base titration of hydroxyl end groups. PCL bisAcAc precursors were reacted with neopentyl glycol diacrylate in the presence of an organic base at room temperature. The crosslinking reactions yielded networks with high gel contents (>85%). The thermomechanical properties of the networks were analyzed to investigate the influence of molecular weight between crosslink points. The glass transition and the extent of crystallinity of the PCL networks were dependent on the molecular weight of the PCL segment. Dynamic mechanical analysis indicated that the plateau modulus of the networks was dependent on the molecular weight of PCL, which was related to the crosslink density of the networks.

Original languageEnglish
Pages (from-to)5437-5447
Number of pages11
JournalJournal of Polymer Science, Part A: Polymer Chemistry
Volume47
Issue number20
DOIs
Publication statusPublished - 2009 Oct 15
Externally publishedYes

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Keywords

  • Biodegradable
  • Crosslinking
  • Michael addition
  • Poly(caprolactone)
  • Polyesters

ASJC Scopus subject areas

  • Polymers and Plastics
  • Organic Chemistry
  • Materials Chemistry

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