Jump to main content
Jump to site search


Microphase separation of carbohydrate-based star-block copolymers with sub-10 nm periodicity

Author affiliations

Abstract

Block copolymers (BCPs) with a high Flory–Huggins interaction parameter (χ) and a low degree of polymerization (N) are being investigated to create microphase-separated structures with sub-10 nm periodicity (d). However, the lowered N value also leads to undesirable properties. In this paper, we demonstrate that the use of a star-block architecture is an effective way to achieve microphase separation with sub-10 nm d without reducing the molecular weight. Thus, three-, four-, and six-armed star-block copolymers consisting of poly(ε-caprolactone) (PCL) and maltotriose (MT), i.e., (PCL-b-MT)x (x = 3, 4, and 6, respectively), with comparable arm lengths and MT volume fractions were synthesized in three steps involving the ring-opening polymerization of ε-caprolactone, chain end modification, and click reaction. Small angle X-ray scattering experiments revealed that the (PCL-b-MT)x microphase separated into hexagonally close-packed cylindrical structures with a d of 6–8 nm. The d value and morphology of (PCL-b-MT)x are essentially the same as those of the corresponding arm unit, i.e., linear diblock copolymers (PCL-b-MTs). In other words, the d value can be fixed at less than 10 nm even though the total molecular weight of the BCP is increased by increasing the arm number. In addition, (PCL-b-MT)x had the advantages of an increased order–disorder transition temperature as well as better quality of the nanostructure formed in the thin film state compared to PCL-b-MT. Overall, well-ordered microphase-separated structures with a d value less than 10 nm were obtained, while the total molecular weight of the BCPs is higher than 10 000 g mol−1.

Graphical abstract: Microphase separation of carbohydrate-based star-block copolymers with sub-10 nm periodicity

Back to tab navigation

Supplementary files

Publication details

The article was received on 08 Dec 2018, accepted on 14 Jan 2019 and first published on 15 Jan 2019


Article type: Paper
DOI: 10.1039/C8PY01745J
Citation: Polym. Chem., 2019, Advance Article

  •   Request permissions

    Microphase separation of carbohydrate-based star-block copolymers with sub-10 nm periodicity

    T. Isono, N. Kawakami, K. Watanabe, K. Yoshida, I. Otsuka, H. Mamiya, H. Ito, T. Yamamoto, K. Tajima, R. Borsali and T. Satoh, Polym. Chem., 2019, Advance Article , DOI: 10.1039/C8PY01745J

Search articles by author

Spotlight

Advertisements