PEG quantification and examination of molecular weight distribution in wood cell walls
2009
Jeremic, Dragica | Cooper, Paul
The amounts of polyethylene glycol (PEG) of a range of molecular weights (200-20000) and their mixtures in wood cell walls were estimated by preferential extraction of PEG from the cell lumens. PEG extracted by toluene over 1 h extraction periods was examined by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) spectroscopy. The assumption that a non-polar solvent would not extract PEG from the cell walls was shown to be invalid. Only about 0.07-0.08 g PEG per g dry wood was retained in wood after 12 h-toluene extraction and this value was not significantly affected by PEG molecular weight (MW). This relatively low cell wall content can result in as high as 50% cell wall bulking (CWB) which is dependent on MW. Samples treated with mixture of PEG MWs indicated preferential penetration of lower MW into cell walls.
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