Morphology and tensile properties of bast fibers extracted from cotton stalks

Abstract

Bast fiber contained in cotton stalk, a residue from the growth of cotton fiber, is available in very large quantities, estimated at more than 15 million tonnes annually. The stalk is currently burnt or buried into soil. In this study, bast fibers were extracted from cotton stalk using a mechanical decortication method. The morphology of single bast fibers, also known as ultimates or ultimate fibers, were characterized by an effective diameter and a cell wall thickening factor (maturity) derived from a concentric circle model reconstructed using an image analysis technique. Fiber cells within the same plant are quite consistent in diameter but can vary considerably in maturity depending on their position in the plant. Eighty percent of the bast fibers were contained in the lower half of the stalk where the fiber maturity was high. Cotton bast fibers are as strong as other bast fibers, such as jute and hemp, and can be used as reinforcement for polymer composite materials.