The Composition of Pyrodextrins. III. Thermal Polymerization of Levoglucosan¹

Secondary decomposition of levoglucosan in pyrolytic production from cellulosic biomass

“…Saccharification through rapid or vacuum pyrolysis of cellulosic biomass has also been proposed as a pretreatment method for ethanol fermentation [12][13][14]. Since the Pictet's report [15] in 1918, polymerization of levoglucosan has been studied extensively [16][17][18][19]. Many kinds of polysaccharides have been prepared from polymerization of levoglucosan [15][16][17] and its derivatives [18,19].…”

“…Since the Pictet's report [15] in 1918, polymerization of levoglucosan has been studied extensively [16][17][18][19]. Many kinds of polysaccharides have been prepared from polymerization of levoglucosan [15][16][17] and its derivatives [18,19].…”

Reinvestigating the Concurring Reactions in Early-Stage Cellulose Pyrolysis by solution state NMR spectroscopy

“…The herein used experimental setup proved to be insufficient to get further insights into the cross-linked fractions by NMR spectroscopy. Given the evidenced presence of LGA structures and the similarities between the products of levoglucosan and cellulose carbonization, [63] there are probably some similarities in their thermo-induced bond formation as well [60][61][62]. The results of LGA thermal polymerization hinted towards a cationic polymerization with an autocatalytic behavior, which adds another layer of complexity to the problem [62].…”

“…Theoretical computations also suggested the formation of LGA-end capped cellulose structures as energetically most favorable thermal transformation [59]. The thermal polymerization of LGA was often investigated, e.g., in the context of pyrodextrin formation [60][61][62] and the similarities between the chars obtained from LGA and cellulose carbonization were pointed out [63]. The occurrence of more reactive anhydroglucose structures obtained from internal isomerization was also evidenced after low temperature treatment of other (poly)saccharides which were easier to analyze [49] and were also connected to char formation [64].…”

Thermal fragmentation analysis of neutral polysaccharides and the presence of 1,6-anhydrooligosaccharides

“…4, shows a large solvent and reagent peak along with a number of small molecular weight products of pyrolysis. There are also three later-eluting peaks whose elution times are 12.9, 20.5, and 23. retention time of the D-labelled peaks, are believed to be various anhydrodisaccharides having different glucosidic linkages as the result of polymerization of levoglucosan in the melt and re-pyrolysis (21,22). It is noteworthy that laminaran (Fig.…”