Study On Biochemical Compound Degreasing Technology Of Cotton Wool

Refined cotton has the characteristics of high fiber content,pure cellulose content,toughness,folding resistance,and high degree of polymerization,and is widely used in industries such as textiles,paper making,and chemical engineering.People usually use cotton linter as raw material to prepare refined cotton through one-step cooking,bleaching,and drying using alkaline hydrogen peroxide method.However,in the process of preparing refined cotton,there are often problems such as high cooking temperature and high alkali consumption,which cause significant environmental pollution.In this thesis,in response to the problems in the preparation process of refined cotton,we selected Class II cotton lint as the raw material.Firstly,Bacillus subtilis was used to pretreat cotton lint to produce fermented cotton,and then refined cotton was prepared using cooking conditions with lower Na OH and H₂O₂concentrations,lower cooking temperature,and less cooking time.Data analysis was conducted on the water absorption,whiteness,and polymerization degree of refined cotton.Finally,a more environmentally friendly biochemical composite degreasing technology for cotton linter was developed.The specific research content is as follows:1、Choose two varieties of second class cotton short staple,Wanzamian 12 and Wanmian 203.A concentration gradient and reaction time gradient experiment was conducted on two bacterial strains,Bacillus subtilis and yeast,to produce fermented cotton.The water absorption rate of the fermented cotton was measured in parallel and the difference in significance was analyzed.Bacillus subtilis was selected as the most suitable bacterial strain.The subsequent experimental results showed that the suitable conditions for producing fermented cotton from short staple cotton of Wanzamian 12 were:the addition amount of Bacillus subtilis was 7.5 mg/L,and the reaction time was 24 hours;The suitable conditions for producing fermented cotton from Wanmian 203 cotton linter are:adding 12.5 mg/L Bacillus subtilis and reaction time of 24 hours.2、On the basis of fermented cotton produced by Bacillus subtilis,the cooking effect of alkaline hydrogen peroxide method with lower H₂O₂dosage,lower cooking temperature,less cooking time,and lower Na OH concentration was investigated through single factor experiments and orthogonal experiments.The final determination of alkaline hydrogen peroxide cooking method is 0.6%sodium hydroxide dosage,cooking temperature of100℃,1%H₂O₂dosage,and cooking time of 60 minutes.Compared with the cotton short staple raw material,the refined cotton prepared by Wanzamian 12 has a water absorption increase of 2.81 times and a whiteness increase of 2.12 times;The water absorption and whiteness of Wanmian 203 have increased by 1.84 times and 2.02 times respectively.3、Observing the microstructure of raw cotton short staple,fermented cotton,and refined cotton of Wanzamian 12 and Wanmian 203 through electron microscopy.It can be seen that after being treated with Bacillus subtilis,the surface pectin,ash and other impurities of the fermented cotton obtained from the two varieties of cotton linters have been reduced.After being steamed with mild alkaline hydrogen peroxide method,the surface of the refined cotton obtained is smooth and free of impurities.