Polymer tethered graphene oxide influences miscibility and cooperative relaxation in LCST blends

Muzata, TS and Bose, S (2020) Polymer tethered graphene oxide influences miscibility and cooperative relaxation in LCST blends. In: Polymer, 188 .

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Abstract

The miscibility of a classical lower critical solution temperature (LCST) system; PMMA/SAN was probed by different rheological fingerprints such as isochronal temperature ramps, and isothermal frequency sweeps, in presence of graphene oxide (GO) and PMMA tethered GO. The chain length of the grafted polymer was varied to study its effect on miscibility, volume cooperativity, entanglement density and localization in the blends. The PMMA tethered GO alters the chain dynamics both at local and cooperative length scale through entropic and enthalpic interactions. It was perceived that the thermodynamic miscibility, cooperative relaxations and concentration fluctuation in PMMA/SAN blends are controlled by the spatial distribution of GO in the blend. By varying the chain length, we were able to understand that shorter tethered chains lead to early phase separation whereas the tethered chain length similar to that of the host matrix delays phase separation. Interestingly, irrespective of the length of the tethered polymer chain, the grafted GO sheets were not localized in the thermodynamically preferred phase (here PMMA). These findings are of great importance to further help us understand the theories and simulations which pertain to chain dynamics of PMMA/SAN blends containing polymer-tethered nanoparticles with large specific surface area like GO

Item Type:	Journal Article
Publication:	Polymer
Publisher:	Elsevier Ltd
Additional Information:	The copyright for this article belongs to the Elsevier Ltd.
Keywords:	Grafting (chemical); Graphene; Phase separation; Polymer blends; Rheology; Solubility, Concentration fluctuation; Enthalpic interactions; Large specific surface areas; Lower critical solution temperature; PMMA-g-GO; PMMA/SAN; Tethered nanoparticles; Thermodynamic miscibility, Chain length
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	02 Feb 2023 07:14
Last Modified:	02 Feb 2023 07:14
URI:	https://eprints.iisc.ac.in/id/eprint/79736

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