BANKS, S. R., SAMMON, C., MELIA, C. D. and TIMMINS, P. (2005). Monitoring the thermal gelation of cellulose ethers in situ using attenuated total reflectance Fourier transform infrared spectroscopy. Applied Spectroscopy, 59 (4), 452-459.Full text not available from this repository.
In this work attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy was used to probe the thermal gelation behavior of aqueous solutions of hydroxypropyl methylcellulose (HPMC), specifically thermal gelation and accompanying precipitation. Cloud point measurements are usually evaluated through turbidity in dilute solutions but the method cannot readily be applied to more concentrated or highly viscous solutions. From the ATR-FTIR data, intensity changes of the v(CO) band marked the onset of gelation and information about the temperature of gelation and the effect of the gel structure on the water hydrogen bonding network was elucidated. Changes in the relative intensities of bands associated with the methoxyl groups and hydrogen-bond-forming secondary alcohol groups indicated that hydrophobic polymer chain interactions were involved in the gelation process. The dominance of inter-molecular H bonding over intra-molecular H bonding within the cellulose ether in solution was also observed. The ATR-FTIR data was in good agreement with measurements of turbidity conducted on the same systems. The work indicates significant potential for the use of ATR-FTIR for the investigation of gelation and cloud point measurements in viscous cellulosic formulations.
|Research Institute, Centre or Group:||Materials and Engineering Research Institute > Polymers Nanocomposites and Modelling Research Centre > Polymers, Composites and Spectroscopy Group|
|Depositing User:||Jill Hazard|
|Date Deposited:||12 Apr 2010 11:25|
|Last Modified:||29 Sep 2010 08:40|
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