Friday 21 December 2012

Cellulose Acetate Nanofibres from Agricultural Waste

Roberto Frassine of the Politecnico di Milano Polymer Engineering  Lab., Milano (Italy) has been using corn-cobs and straw, wheat straw and even seaweed as a source of cellulose for acetylation – a process which normally requires the highest quality dissolving pulp.  The cellulose extraction and purification process involves Toluene/Ethanol extraction of waxes followed by bleaching first with alkaline peroxide and then with an acetic/formic acid/hydrogen peroxide mixture. 

A final peroxide extract yields a pure cellulose with a DP rather lower than that obtained from wood.  This was acetylated  and dissolved in dichloromethane/methanol for electrospinning to nonwovens.  At acetate concentrations of 7% and 10% the nonwovens were of good quality.  A lab. scale batch reactor has now been built to allow 1.5kg batches of acetate to made for future experimentation.

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