Study On The Degumming Effect Of Apocynum Apocynum On The Breakdown Of The Resistive Barrier Structure By The Complex Flora

Apocynum fiber fabric is favored by consumers for its comfort and unique functionality.At present,the industrialized production of hemp fiber still uses chemical alkali boiling degumming,which has the problems of high energy consumption and environmental pollution.At the same time,it will also damage the performance and gloss of the fiber.Biological degumming is clean and environmentally friendly,but it cannot be fully applied to practical production because of its unstable degumming effect.According to the current demand for sustainable development,this paper explored an efficient biodegumming method,focusing on the two key points of biodegumming:biological catalyst and substrate,and innovatively constructed the composite flora of bacteria and fungi,and analyzed the substrate structure.The selection of degumming strains,the removal of substrate bio-resistance barrier and the optimization of degumming process were studied to achieve pretreatment and synergistic biological degumming of Apocynum and improve the utilization value of Apocynum phloem fiber.In this paper,Bacillus subtilis and Phanerochaete chrysosporium with strong degradation ability to pectin,lignin and hemicellulose were screened out through the analysis of the glial components of apocynum phloem fibers,and the two strains were used to construct a composite degumming flora.The results showed that the compound microbial system could promote the growth and metabolism of the two bacteria,and increase the biomass and enzyme activity.Compared with the single strain,the residual gum rate decreased by 7 % when this microflora was used for degumming.After the analysis and characterization of the structure of bast fiber,it was found that the hydrophobic wax and lignin covered on the fiber surface played a role of contact barrier in the process of biological degumming,which prevented the contact between biological catalyst and substrate.The dense network structure and colloid system inside the fiber became the transmission barrier of biocatalyst the biocatalyst,while the flavonoids antibacterial substances contained in the bast fiber were a natural biochemical barrier to inhibit the role of microorganisms,which constituted the biological resistance barrier of bast fiber.Three physical pretreatment methods,including ultrasonic,supercritical carbon dioxide and freezing,can break the resistance barrier,change the morphological structure of the substrate,increase the pore size,reduce the crystallinity of the fiber,change its thermal stability,and improve the accessibility of the substrate to the biological catalyst,thereby improving the biological degumming effect.Bio degumming was carried out before and after pretreatment,and the difference of residual gum rate was 5 ～ 7 %.In order to improve the synergistic effect of pretreatment and microbial degumming,the degumming process was optimized by response surface design.Under the optimal process,the weight loss rate of the phloem can reach 32.1 %,which basically reaches the effect of chemical degumming.The supercritical carbon dioxide with the best effect and the composite flora degumming have better effect than chemical degumming,reaching the demand of textile production.