Choosing the Right Strategy: Cryogrinding vs Ball Milling – Comparing Apples to Apples

Despite many reports on ball milling (BM) of chitin, the effect of cryomilling of chitin has not yet been reported, even though it is a solventless and environmentally-friendly method for the processing of chitin polymer. In this work, commercially available chitin has been cryoground for up to 96 min and the resulting morphological and chemical changes after cryomilling were monitored and compared with those induced by BM. FE-SEM analysis (1000×) revealed that cryogrinding resulted in size reduction of chitin particles and the size reduction was proportional to cryogrinding time. FTIR followed by PCA analysis revealed the breaking of intra- and intermolecular hydrogen bonds, partial amorphization, and insignificant breaking of glycosidic bonds after up to 48 min of cryogrinding, whereas an increase of cryogrinding time to 96 min resulted in a slightly higher number of broken bonds and highly amorphous material. The crystalline structure analysis demonstrated a decrease of crystallini