Synthesis and morphological characterization of miktoarm star copolymers (PCL)2(PS)2 of poly(ε-caprolactone) and polystyrene

Arnaldo T. Lorenzo, Alejandro J. Müller*, Dimitrios Priftis, Marinos Pitsikalis, Nikos Hadjichristidis

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

38 Scopus citations


An heterofunctional initiator combining two reactive sites for ring opening polymerization and two for atom transfer radical polymerization was used to prepare three A2B2 miktoarm star copolymers of poly(ε-caprolactone) (PCL) and polystyrene (PS). The morphology and thermal properties were studied by transmission electron microscopy, polarized light optical microscopy, and differential scanning calorimetry. The (PCL) 2(PS)2 72/28 (72 wt % PCL) sample was crystallized from a disordered melt. In this case, crystallization drove the structure formation and a lamellar morphology was obtained at the microdomain level, while spherulites were observed at a superstructural level. The other two samples, 39/61 and 27/73, with lower PCL content and higher total molecular weight, were not able to form spherulites. Surprisingly, these miktoarm star copolymers exhibited hexagonally packed cylinders and spheres morphologies, respectively, instead of lamellar and cylindrical morphology. Such unexpected and novel behavior was explained in terms of the higher resistance of the arms to be stretched in a miktoarm star copolymer when compared with the corresponding linear diblocks.

Original languageEnglish (US)
Pages (from-to)5387-5397
Number of pages11
JournalJournal of Polymer Science, Part A: Polymer Chemistry
Issue number23
StatePublished - Dec 1 2007
Externally publishedYes


  • Crystallization
  • Differential scanning calorimetry (DSC)
  • Living radical polymerization
  • Miktoarm stars
  • Polarized optical microscopy
  • Ring-opening polymerization
  • TEM

ASJC Scopus subject areas

  • Polymers and Plastics
  • Organic Chemistry
  • Materials Chemistry


Dive into the research topics of 'Synthesis and morphological characterization of miktoarm star copolymers (PCL)2(PS)2 of poly(ε-caprolactone) and polystyrene'. Together they form a unique fingerprint.

Cite this