CHEMICAL AND PULPING CHARACTERISTICS OF CORN STALK FRACTIONS

摘要

Two different varieties of domestic, whole corn stalk were separated into three fractions: stalk (depithed), leaves, and husks. One variety had almost twice the pith content of the other. A portion of each fraction was milled and tested for ash content, hot water solubles, NaOH solubles, solvent extractives, and klason lignin content. With respect to lignin content, the test values showed that stalks > leaves > husks. Ash content values were similar for all three fractions. NaOH solubility varied according to leaves > husks > stalks. Hot water solubility and solvent extractives were similar for the fractions of one variety, but for the other variety the stalk fraction had much higher values. While the leaf fraction of both varieties had similar composition, the stalk and husk fractions of one variety had a much higher level of ash, water solubles, and extractives than for the other variety. Each (unmilled) fraction was pulped, using a mild soda-AQ process. For both varieties, the stalk fraction had higher total and screened yields than the other fractions. The variety with higher ash, solubles, and extractives had a much poorer response to pulping, with the stalk fraction requiring 37 % more alkali to reach a bleachable Kappa number. Fiber length values for the unbleached pulps were similar to those for hardwoods, but the fiber width values were lower.