Tailoring the Degree of Polymerization of Low Molecular Weight Cellulose

The degradation of cellulose to lmw samples with (DP) over bar (w) varying from 15 to 130 is investigated. Cellulose samples prepared from the hydrolysis of regenerated cellulose fibers in dilute HCl possess (DP) over bar (w) = 50. Applying homogenous degradation of microcrystalline cellulose in H3PO4 at RT for 3 weeks, samples with (DP) over bar (w) = 35 and a PDI of 1.58 are obtained. Decreasing the hydrolysis temperature to 8 degrees C results in lmw cellulose with (DP) over bar (w) > 70. Fractionation in DMA/LiCl provides samples with (DP) over bar (w) 12 to 130, together with a narrow molecular weight distribution. Detailed structural analysis by 2D NMR spectroscopy reveals that the prepared lmw celluloses are suitable as mimics for cellulose.