CERTAIN CHARACTERISTICS OF THE DISSOLVED ALKALI LIGNINS OF 4 ANGIOSPERM PLANT-SPECIES

Two dicotyledoneous angiosperm biomasses, cottonwood and jute bast fiber, were delignified under alkaline conditions and the dissolved lignins are confirmed to be of relatively low molecular weights (Mw = 2000-4300). Two monocotyledoneous angiosperms, wheat straw and sugar cane bagasse, were also delignified and the dissolved lignins were generated somewhat more rapidly than from the dicot plants tissue - these lignins, too, proved to be of low molecular weight. (Mw = 1700-3400)The erythro/threo (E/T) ratios associated with the in situ, and also the undissolved residual dicotyledoneous lignins, were within the range found for other hardwoods whereas the ratios found for the monocotyledoneous fell between the levels previously observed for hardwoods and for softwoods. Low molecular weight lignins, such as those now generated from the monocotyledoneous, may find uses in industry in certain parts of the world where such biomasses are used for production of cellulose pulps (for example, wheat straw in China).