Preparation And Study Of Cellulose Foam Materials

In this paper, cellulose foam materials were prepared by wood pulp cellulose which wasdissolved in Zinc chloride aqueous solution and absorbent cotton was added to it as reinforcedfibers, selected anhydrous sodium sulfate as pore-forming agent dissolving in the process ofwater curing to form pores. After all cellulose foam materials were dried by freeze dryingmethod. Designed orthogonal experiment to detect the influence of Zinc chloride mass,dissolution time, dissolution temperature on the dissolving properties, and using glycerol asplasticizer to soft cellulose foam materials whose breaking force and bending angle wereindex to study the influence of the mass of glycerol, processing time and processingtemperature.First, the factors which influenced the dissolution properties of zinc chloride aqueoussolution were studied, such as the structure changes of cellulose through FTIR, x-raydiffraction and thermogravimetric analysis. Detailed study was held to research thedissolution conditions including zinc chloride mass, dissolution time and dissolutiontemperature which proved that dissolution was the biggest influence factors, dissolution timewas secondly factors and zinc chloride mass was the minimal impact factor. The bestdissolving process is in80℃to dissolving cellulose in68%of the zinc chloride for60min.Meanwhile, each factors were discussed and drew a conclusion that with zinc chloride massincreasing the dissolution properties were decreased for the solution becoming more viscosity,on the contrary, with temperature increasing the dissolution properties increasing throughmore severe reaction conditions. However, zinc chloride aqueous solution can’t completelydissolve cellulose when the cellulose content beyond7%. Regenerated cellulose has the samegroup as cellulose which indicated the zinc chloride aqueous solution is derivative solventsand its degree of crystallinity decreased as well as thermostability. The preparation process ofcellulose foam materials was discussed in second part and tested breaking force, hygroscopicproperties, and pore structure. The results proved that breaking force increased with cellulosecontent; on the other hand, breaking force decreasing with foaming agent increases. The bestcellulose foam materials were prepared with conditions that cellulose content is5%; foamingagent is1.5times than solution; absorbent cotton content is40%of cellulose. And thebreaking force is1.72MPa; moisture rate is7.8times; porosity is75%. In the last part softcellulose foam materials were prepared by immersed in glycerol solution and tested variousphysical and chemical properties which indicated that the best soft cellulose foam materialswere prepared at30℃in8%glycerol solution for6hours. The soft cellulose foam materialscan be used in many ways because of its excellent hygroscopicity and mechanical strength.