Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Synthesis and Characterization of a Thermoresponsive Copolymer with an LCST-UCST-like Behavior and Exhibiting Crystallization

Gjerde, Natalie Solfrid ; Del Giudice, Alessandra LU orcid ; Zhu, Kaizheng ; Knudsen, Kenneth D. ; Galantini, Luciano LU ; Schillén, Karin LU orcid and Nyström, Bo (2023) In ACS Omega 8(34). p.31145-31154
Abstract

In this work, the diblock copolymer methoxy-poly(ethylene glycol)-block-poly(ϵ-caprolactone) (MPEG-b-PCL) was synthesized with a block composition that allows this polymer in aqueous media to possess both an upper critical solution temperature (UCST) and a lower critical solution temperature (LCST) over a limited temperature interval. The value of the UCST, associated with crystallization of the PCL-block, depended on heating (H) or cooling (C) of the sample and was found to be CPUCSTH = 32 °C and CPUCSTC = 23 °C, respectively. The LCST was not affected by the heating or cooling scans; assumed a value of 52 °C (CPLCSTH = CPLCSTC). At intermediate... (More)

In this work, the diblock copolymer methoxy-poly(ethylene glycol)-block-poly(ϵ-caprolactone) (MPEG-b-PCL) was synthesized with a block composition that allows this polymer in aqueous media to possess both an upper critical solution temperature (UCST) and a lower critical solution temperature (LCST) over a limited temperature interval. The value of the UCST, associated with crystallization of the PCL-block, depended on heating (H) or cooling (C) of the sample and was found to be CPUCSTH = 32 °C and CPUCSTC = 23 °C, respectively. The LCST was not affected by the heating or cooling scans; assumed a value of 52 °C (CPLCSTH = CPLCSTC). At intermediate temperatures (e.g., 45 °C), dynamic light scattering (DLS), small-angle X-ray scattering (SAXS), and cryogenic transmission electron microscopy (cryo-TEM) showed that the solution consisted of a large population of spherical core-shell particles and some self-assembled rodlike objects. At low temperatures (below 32 °C), differential scanning calorimetry (DSC) and wide-angle X-ray scattering (WAXS) in combination with SAXS disclosed the formation of crystals with a cylindrical core-shell structure. Cryo-TEM supported a thread-like appearance of the self-assembled polymer chains. At temperatures above 52 °C, incipient phase separation took place and large aggregation complexes of amorphous morphology were formed. This work provides insight into the intricate interplay between UCST and LCST and the type of structures formed at these conditions in aqueous solutions of MPEG-b-PCL diblock copolymers.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Copolymers, Crystallization, Crystals, Micelles, X-ray scattering
in
ACS Omega
volume
8
issue
34
pages
31145 - 31154
publisher
The American Chemical Society (ACS)
external identifiers
  • scopus:85169057574
  • pmid:37663484
ISSN
2470-1343
DOI
10.1021/acsomega.3c03162
language
English
LU publication?
yes
id
cb7b6f0c-20b1-4e6a-b80a-01054e8d93b7
date added to LUP
2023-09-14 11:00:47
date last changed
2024-06-15 08:24:30
@article{cb7b6f0c-20b1-4e6a-b80a-01054e8d93b7,
  abstract     = {{<p>In this work, the diblock copolymer methoxy-poly(ethylene glycol)-block-poly(ϵ-caprolactone) (MPEG-b-PCL) was synthesized with a block composition that allows this polymer in aqueous media to possess both an upper critical solution temperature (UCST) and a lower critical solution temperature (LCST) over a limited temperature interval. The value of the UCST, associated with crystallization of the PCL-block, depended on heating (H) or cooling (C) of the sample and was found to be CP<sub>UCST</sub><sup>H</sup> = 32 °C and CP<sub>UCST</sub><sup>C</sup> = 23 °C, respectively. The LCST was not affected by the heating or cooling scans; assumed a value of 52 °C (CP<sub>LCST</sub><sup>H</sup> = CP<sub>LCST</sub><sup>C</sup>). At intermediate temperatures (e.g., 45 °C), dynamic light scattering (DLS), small-angle X-ray scattering (SAXS), and cryogenic transmission electron microscopy (cryo-TEM) showed that the solution consisted of a large population of spherical core-shell particles and some self-assembled rodlike objects. At low temperatures (below 32 °C), differential scanning calorimetry (DSC) and wide-angle X-ray scattering (WAXS) in combination with SAXS disclosed the formation of crystals with a cylindrical core-shell structure. Cryo-TEM supported a thread-like appearance of the self-assembled polymer chains. At temperatures above 52 °C, incipient phase separation took place and large aggregation complexes of amorphous morphology were formed. This work provides insight into the intricate interplay between UCST and LCST and the type of structures formed at these conditions in aqueous solutions of MPEG-b-PCL diblock copolymers.</p>}},
  author       = {{Gjerde, Natalie Solfrid and Del Giudice, Alessandra and Zhu, Kaizheng and Knudsen, Kenneth D. and Galantini, Luciano and Schillén, Karin and Nyström, Bo}},
  issn         = {{2470-1343}},
  keywords     = {{Copolymers; Crystallization; Crystals; Micelles; X-ray scattering}},
  language     = {{eng}},
  month        = {{08}},
  number       = {{34}},
  pages        = {{31145--31154}},
  publisher    = {{The American Chemical Society (ACS)}},
  series       = {{ACS Omega}},
  title        = {{Synthesis and Characterization of a Thermoresponsive Copolymer with an LCST-UCST-like Behavior and Exhibiting Crystallization}},
  url          = {{http://dx.doi.org/10.1021/acsomega.3c03162}},
  doi          = {{10.1021/acsomega.3c03162}},
  volume       = {{8}},
  year         = {{2023}},
}