Universität zu Köln

Bras, Ana, Arizaga, Ana, Agirre, Uxue, Dorau, Marie, Houston, Judith, Radulescu, Aurel ORCID: 0000-0002-6050-0176, Kruteva, Margarita ORCID: 0000-0002-7686-0934, Pyckhout-Hintzen, Wim and Schmidt, Annette M. (2021). Chain-End Effects on Supramolecular Poly(ethylene glycol) Polymers. Polymers, 13 (14). BASEL: MDPI. ISSN 2073-4360

Full text not available from this repository.

Abstract

In this work we present a fundamental analysis based on small-angle scattering, linear rheology and differential scanning calorimetry (DSC) experiments of the role of different hydrogen bonding (H-bonding) types on the structure and dynamics of chain-end modified poly(ethylene glycol) (PEG) in bulk. As such bifunctional PEG with a molar mass below the entanglement mass M-e is symmetrically end-functionalized with three different hydrogen bonding (H-bonding) groups: thymine-1-acetic acid (thy), diamino-triazine (dat) and 2-ureido-4[1H]-pyrimidinone (upy). A linear block copolymer structure and a Newtonian-like dynamics is observed for PEG-thy/dat while results for PEG-upy structure and dynamics reveal a sphere and a network-like behavior, respectively. These observations are concomitant with an increase of the Flory-Huggins interaction parameter from PEG-thy/dat to PEG-upy that is used to quantify the difference between the H-bonding types. The upy association into spherical clusters is established by the Percus-Yevick approximation that models the inter-particle structure factor for PEG-upy. Moreover, the viscosity study reveals for PEG-upy a shear thickening behavior interpreted in terms of the free path model and related to the time for PEG-upy to dissociate from the upy clusters, seen as virtual crosslinks of the formed network. Moreover, a second relaxation time of different nature is also obtained from the complex shear modulus measurements of PEG-upy by the inverse of the angular frequency where G' and G'' crosses from the network-like to glass-like transition relaxation time, which is related to the segmental friction of PEG-upy polymeric network strands. In fact, not only do PEG-thy/dat and PEG-upy have different viscoelastic properties, but the relaxation times found for PEG-upy are much slower than the ones for PEG-thy/dat. However, the activation energy related to the association dynamics is very similar for both PEG-thy/dat and PEG-upy. Concerning the segmental dynamics, the glass transition temperature obtained from both rheological and calorimetric analysis is similar and increases for PEG-upy while for PEG-thy/dat is almost independent of association behavior. Our results show how supramolecular PEG properties vary by modifying the H-bonding association type and changing the molecular Flory-Huggins interaction parameter, which can be further explored for possible applications.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Bras, Ana UNSPECIFIED UNSPECIFIED UNSPECIFIED Arizaga, Ana UNSPECIFIED UNSPECIFIED UNSPECIFIED Agirre, Uxue UNSPECIFIED UNSPECIFIED UNSPECIFIED Dorau, Marie UNSPECIFIED UNSPECIFIED UNSPECIFIED Houston, Judith UNSPECIFIED UNSPECIFIED UNSPECIFIED Radulescu, Aurel UNSPECIFIED orcid.org/0000-0002-6050-0176 UNSPECIFIED Kruteva, Margarita UNSPECIFIED orcid.org/0000-0002-7686-0934 UNSPECIFIED Pyckhout-Hintzen, Wim UNSPECIFIED UNSPECIFIED UNSPECIFIED Schmidt, Annette M. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-576918
DOI:	10.3390/polym13142235
Journal or Publication Title:	Polymers
Volume:	13
Number:	14
Date:	2021
Publisher:	MDPI
Place of Publication:	BASEL
ISSN:	2073-4360
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language TRANSIENT NETWORKS; THERMOPLASTIC ELASTOMERS; VISCOELASTIC PROPERTIES; TELECHELIC POLYMERS; NEUTRON-SCATTERING; PHASE-SEGREGATION; MOLECULAR-WEIGHT; RHEOLOGY; DYNAMICS; SHEAR Multiple languages Polymer Science Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/57691