Study On Process And Mechanism Of Antibacterial Modifying Of Fluff Pulp

As a kind of material with good absorption, fluff pulp is widely used in the manufacture of disposable sanitary products, such as baby diapers, women’s sanitary napkin, and adult incontinence products. The products make from fluff pulp usually close contact with human body. But, fluff pulp itself doesn’t have antibacterial ability and it will result in the rapid multiplication of bacteria in the comfortable environment. It could lead to the infection of human and do harm to the health of human. Hence, if fluff pulp is given the antibacterial activity, the rapid multiplication of bacteria can be inhibited. It is of great significance to the health of human being. In this paper, therefore, nano-silver particles and quaternary ammonium salt are used as antibacterial agent to give fluff pulp antibacterial activity. On the basis of antibacterial modification process, the mechanism of antibacterial modification was also studied.The cellulose fiber was used as template and reducing agent, the silver-loaded cellulose fiber was obtained by water bath heating and microwave heating. It was found that the high pulp concentration and long heating time were conducive to increasing the silver content in silver-loaded cellulose and the utilization rate of silver ions. The microwave heating offers advantages over water bath heating in increasing the silver content and the utilization rate of silver ions. Besides, the incorporation of alkalis can greatly increase the silver content and the utilization rate of silver ions. The incorporation of ammonia had little effect on increasing the silver content and the utilization rate of silver ions. The incorporation of sodium hydroxide can greatly increase the silver content and the utilization rate of silver ions. At the same dosage of alkali, compared with the former two, sodium carbonate had a best result on increasing the silver content and the utilization rate of silver ions. With the increasing of silver content, internal bond strength of fiber decreased, and high silver content had slightly adverse effects on the absorption of fiber. At the same time, high silver content can obviously decrease the brightness of fiber, and the brightness of fiber can decrease from 85.2 %ISO to 3.1 %ISO. The incorporation of PVP can increase the brightness of silver-loaded cellulose distinctly, but it also can decrease the silver content and the utilization rate of silver ions. The incorporation of alkalis can make cellulose generate more active site on the fiber surface. The more active site can lead to more nano-silver crystal nucleus formed on the fiber surface, which resulted in the size of silver nanoparticles decreased eventually. The incorporation of alkalis can generate a small amount of silver oxide and silver carbonate on the fiber surface, and more hydroxyl groups were oxidized into carboxyl. The silver-loaded cellulose fiber and untreated cellulose fiber were mixed to prepare the antibacterial fluff pulp. When proportion of silver-loaded cellulose was 10%, over 90% of bacteria can be killed in 60 min.After cellulose fiber was treated with xylane, the fiber surface became rough with the hydrolysis of hemicellulose on the fiber surface. In the hemicellulose hydrolysis process, more reductive groups were explored on the fiber surface. It was conductive to increasing the reduction of cellulose.A kind of ester-based quaternary ammonium salt with good antibacterial activity was synthesized and used as antibacterial agent to give fluff pulp antibacterial activity. Compared with the antibacterial fluff pulp which quaternary ammonium salt was add in the process of papermaking, the antibacterial fluff pulp which was obtained by immersing into the quaternary ammonium salt solution can absorb more quaternary ammonium salt. After adsorbed quaternary ammonium salt, the antibacterial fluff pulp had smaller density and burst strength index. When the quaternary ammonium salt addition amount was high, it will have an obvious impact on the bulkiness and absorption. When the dosage of quaternary ammonium salt is under 6.25%, the density, burst strength index, bulkiness, and absorption were acceptable. The quaternary ammonium salt kills bacteria by breaking the structure of bacteria, and high dosage of quaternary ammonium salt has a better antibacterial activity.