Research, Synthesis And Its Modified Of Liquefied Rice Straw Polyurethane Foam Materials

In this paper, rice straw polyol liquefaction technology used two experimentally systems were studied, a system for:The catalyzed liquefaction degradation of rice straw for preparation of polyols in the system of sulfuric acid as catalyst as a catalyst and glycol liquefier had been studied. Through the single factor analysis method, the effect of the processing conditions of rice straw liquefaction on the liquefaction reaction and properties of liquefaction product were investigated. Determine the liquefied product can be better than the performance of other conditions liquefaction reaction conditions for subsequent research and utilization of liquefied product. The results showed that rice straw had good liquefaction effect, the optimum liquefaction processing conditions were determined as follows:reaction temperature160?, reaction time90min, catalyst concentration10%(Based on Solid), solvent-solid ratio5:1, glycol concentration20%, highest liquefaction percent would reach55.6%. An acid value of less than4.2mgKOH/g, Hydroxyl number of polyols product was350mgKOH/g, which was a higher hydroxyl number polyols. Catalyst for liquefying agent by mass3%, effects of reaction temperature, reaction time, liquid to solid ratio on rice straw liquefaction rate and performance, analyzed by single factor experiment showed that the liquefaction temperature of180?, liquid-solid ratio8:1, liquefying agent ratio of9:1, the reaction time was90min under conditions, we can prepare the liquefaction rate of90%and acid value of less than15mg/g, a hydroxyl value of254mgKOH/g of liquefied polyol, in line with the polyurethane polyol foam material preparation required, but such a high cost of the liquefaction process, polyurethane foam used in the following studies are under polyol system a condition in the system.With the above system, a product was obtained pure liquefied preparing a polyurethane foam, and its further analysis, Studied isocyanate index, water content, and the proportion of the catalyst, amount of silicone oil effect on properties of the polyurethane foam. The results showed that liquefied rice straw and isocyanate (PAPI) as raw materials, water as a blowing agent, and triethylenediamine and stannous octoate as catalyst, water-soluble silicone oil as foam stabilizer, isocyanate index of1.2was prepared good properties of the polyurethane foam (PU). The foam of density35.8Kg/m3, tensile strength of222.6KPa, compressive strength of110.9KPa, TGA analysis indicated rice straw-based polyurethane foam had good heat resistance.Liquefaction products of containing residues in the above-mentioned preparation containing residues of rice straw-based polyurethane foam. The various influence factors were discussed, and the thermal and mechanical properties were evaluated by TGA and strength measurement. The results showed that the foam density was got from36.1Kg/m3to67Kg/m3. The foam maximum compressive was73KPa and the maximum tensile was163.3KPa. FT-IR and SEM indicated that the urethane linkages were successfully formed and the cellular structure of foams was evenly distributed, closed cell rate higher.On the basis of studies of containing residue rice straw-based polyurethane foam, and further study of the nano-silica enhanced rice straw-based polyurethane foam, the effects of nano-silica addition on properties of foam. The results showed that with the increase of nano-silica, the foam compressive strength was significantly enhanced. SEM images showed that nano-silica mainly in the cell wall and frame junction of nanoparticles added to make the cell more uniform, fine.