Add time:08/21/2019         Source:sciencedirect.com

Beech wood organosolv lignin was modified with propylene carbonate (PC) in an efficient, facile and solvent-free procedure without using highly toxic and explosive propylene oxide (PO). Comparative studies of the oxyalkylation procedure were performed varying crucial reaction conditions. The results of FTIR, 1H NMR, 13C NMR and 31P NMR spectroscopic analyses revealed that the OH group activation of lignins differed significantly depending on catalyst, catalyst to lignin ratio, reaction time, temperature and PC amount. Under optimized reaction conditions using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as catalyst, a degree of substitution (DS) of 0.92 and chain lengths of up to 4.6 propyl units were achieved, yielding 0.3% of carbonate linkages in the grafted chain. This oxyalkylation procedure using safe and non-toxic PC represents a promising alternative to PO for the preparation of lignin polyols concerning the substitution of conventional petroleum-based polyols.

We also recommend Trading Suppliers and Manufacturers of Methyl propyl carbonate (cas 1333-41-1). Pls Click Website Link as below: cas 1333-41-1 suppliers