Structure and properties of bast fiber of Alchornea Davidii Franch based on chemical alkali degumming and biological enzyme degumming

Abstract

In this work, the effects of degumming treatment on the structure and properties of OS-BADF were discussed. Alkali degumming and biological enzyme degumming were used to obtain AD-BADF and BED-BADF respectively. Spinnability index, thermal property, macromolecular structure, bending property and antibacterial property of OS-BADF (Original Sample of Bast Fiber of Alchornea Davidii Franch), AD-BADF (Alkali Degummed Bast Fiber of Alchornea Davidii Franch), and BED-BADF (Biological Enzyme degummed Bast Fiber of Alchornea Davidii Franch) were tested. The surface morphology of the above three kinds of fiber was analyzed by SEM. The results showed that the main component of degummed OS-BADF was cellulose, and the fiber had stripes in longitudinal direction, and kidney ellipsoid, irregular polygon in the cross section. After degumming treatment, the fineness of fiber decreased obviously and reached the spinnability index. Non-cellulose substances in OS-BADF can be removed by degumming. SEM observation showed that AD-BADF and BED-BADF became smoother after degumming. Compared with AD-BADF, BED-BADF had finer linear density, better thermal stability and higher antibacterial property. The equivalent flexural modulus and flexural rigidity of AD-BADF and BED-BADF were decreased compared with OS-BADF. In particular, the equivalent flexural modulus and the flexural rigidity of BED-BADF were mostly reduced, which indicated that BED-BADF became thinner and softer. The initial thermal decomposition temperature and the highest thermal decomposition temperature of AD-BADF and BED-BADF had been significantly increased. And -OH (free group) decreased significantly after degumming treatment. The testing results of the antibacterial properties of the three blended fabrics showed that the antibacterial properties of AD-BADF and BED-BADF were improved. Compared with AD-BADF, the antibacterial properties of BED-BADF were improved significantly. On the one hand, this research can provide a basis for technological research for the development of ADF (Alchornea Davidii Franch) bast fiber blended yarn and its textile product development. On the other hand, because of the high mechanical properties of ADF bast fiber, it also provides new development idea for the development of natural high-performance fiber reinforcement composites.