Atmospheric acetic acid pulping of rice straw IV: Physico-chemical characterization of acetic acid lignins from rice straw and woods. part 2. Chemical structures
Xj. Pan et Y. Sano, Atmospheric acetic acid pulping of rice straw IV: Physico-chemical characterization of acetic acid lignins from rice straw and woods. part 2. Chemical structures, HOLZFORSCH, 53(6), 1999, pp. 590-596
Acetic acid lignins from rice straw (RLs), birch (BL) and fir (FL) were che
mically characterized by means of elementary analysis, functional groups an
alysis, alkaline nitrobenzene and permanganate oxidation, Mannich reactivit
y and other techniques. The results showed that RLs had higher contents of
residual polysaccharide and protein, and remarkably fewer acetyl groups tha
n BL and FL. Results of nitrobenzene and permanganate oxidation indicated t
hat RLs were remarkably more condensed than the native lignin in rice straw
. In addition, the results of Mannich reactivity showed that RLs were more
reactive toward modification than BL and FL, and might be a good raw materi
al for lignin derivatives, such as lignin adhesives and chelating resins.