Molecular and mechanical properties of hydroxypropyl methylcellulose solutions during the sol:gel transition

BAJWA, G. S., SAMMON, C., TIMMINS, P. and MELIA, C. D. (2009). Molecular and mechanical properties of hydroxypropyl methylcellulose solutions during the sol:gel transition. Polymer, 50 (19), 4571-4576.

Full text not available from this repository.
Link to published version::


This paper outlines the latest findings in our work to understand the fundamental interactions within hydrated hydroxypropyl methylcellulose (HPMC) at elevated temperature. ATR-FTIR spectroscopy was used to relate molecular interactions to the theological changes in aqueous HPMC solutions during the sol:gel transition. Sol:gel transition temperatures determined using ATR-FTIR spectroscopy, oscillatory rheology and turbidimetry were in agreement to within experimental error. ATR-FTIR spectroscopy provided direct evidence of increased hydrophobic interactions within the gel network through a shift to lower wavenumber of v(as)(CH) vibrations observed during the gelation process. In addition, the FTIR spectra provide evidence that the structure of the polymer network is different in the thermo-formed gel, to that which exists in viscous solution. Both the theological and ATR-FTIR data confirmed the supposition that thermal gelation is a two stage process. The first stage has been attributed to the disruption of native cellulosic bundles and this is supported by the changes in both the storage modulus and intensity of the v(CO) band at low temperatures. The second stage corresponded to phase separation and gelation resulting from increased hydrophobic interactions between polymer chains at elevated temperatures. (C) 2009 Elsevier Ltd. All rights reserved.

Item Type: Article
Research Institute, Centre or Group - Does NOT include content added after October 2018: Materials and Engineering Research Institute > Advanced Coatings and Composites Research Centre > Polymers, Composites and Spectroscopy Group
Identification Number:
Page Range: 4571-4576
Depositing User: Jill Hazard
Date Deposited: 12 Apr 2010 11:26
Last Modified: 18 Mar 2021 21:30

Actions (login required)

View Item View Item


Downloads per month over past year

View more statistics