Synthesis And Properties Research Of A New Sand Fixing Agent Lignin Sulfonate Graft Urea-Formaldehyde Resin

We synthesized a soluble sand-fixation dust suppression agent sulfonation of lignin urea formaldehyde resin with good curative capability by graft copolymerization. The raw materials were urea, formaldehyde, lignin sulfonate. The agent was synthesized with sodium bisulfate as sulfonation agent, melamine as modifier, the reaction temperature and pH under strict control. The sand-fixation dust suppression agent diluted by water can be used to suppress dust on bare soil, construction sites, mines, docks pile and coal railway transportation. Combined with plant sand fixation technique for preventing soil surface soil movement, it has reached purpose of dust suppression purposes. The development of this sand-fixation dust suppression agent and dust suppression technology has good prospects in environmental protection and sand dust suppression.This paper completed the following research work:1.grafting sodium lignosulphonate agent with good curative capability by graft copolymerization.with urea as the main raw material, In order to explore the optimum synthesis conditions, we changed the molar ratio of urea and formaldehyde, urea feed times, pH and temperature of the polycondensation reaction, and the amount of lignin sulfonate. The final synthesis conditions were confirmed by evaluating the viscosity of final product, the free formaldehyde content, placement stability of the product and the mobility of emulsion. The experimental results showed that the synthetic latex got good performance in application which can meet the actual sand fixation needs when the molar ratio of formaldehyde and urea was 1 to 3, inputed urea three times with quality ratio being 7:2:1,the pH of polycondensation reaction was 4.5 and the polycondensation reaction temperature was 80 ℃.2.A variety of properties tests were taken on the new sand-fixation dust suppression agent which included quantitative test of solids and free formaldehyde, sulfonated rate test, infrared spectroscopy analysis, scanning electron microscopy analysis. We found that the solids content of sand-fixation dust suppression agent is 5%-10%, it can satisfy the application for suppress dust, the content of free formaldehyde was under safety line with national standards, which can be used with no worry. The viscosity of the emulsion increased when the solid content rised or temperature decrease, while the viscosity of the emulsion decreased when storage time elongated. The sulfonated rate of product was 84%. We known that the graft of sodium lignin sulfonate and urea-formaldehyde resins was successful through infrared spectroscopy. In scanning electron microscopy analysis, the particle morphology of sodium lignin sulfonate, sulfonated urea-formaldehyde resins and the new sand-fixation dust suppression agent has changed after reaction.3.We also have taken a series of application tests on the new sand-fixation dust suppression agent. There were morphological observation of the consolidated layer on sand surface, compressive strength test of sand column, the water retention properties of sand column, anti-wind erosion ability of sandpile, freeze-thaw performance of sand column, polymer degradation performance and thermal stability performance of the sand-fixation dust suppression agent. The results confirmed that:①After curing of consolidation layer, it has very good dust suppression effect. ②While solids content is 5%, the compressive strength of sand column is 1.182MPa.③Simulated desert wind erosion experiment of the big air volume, there is almost no quality loss.④The freezing and thawing experiment show that after sever times of tests, the compressive strength does not decrease.⑤Thermal stability show that temperature under 160 ℃,sand-fixation dust suppression agent maintain stability.⑥The sand-fixation dust suppression agent will gradually degraded after curing a month later. From the economic and applicability analysis, this sand-fixation dust suppression can used in construction sites, mines windrow pier and solids earth of small slope, the solids content of 5% meet the application conditions,sodium lignin sulfonate is renewable source with abundant resources. Used as sand-fixation dust suppression agent, sodium lignin sulfonate has dafects such as low intensity and fast degradation rate. We synthesized a new sand-fixation dust suppression agent with sodium lignin sulfonate and urea-formaldehyde resin, for the chemically active characteristic of sodium lignin sulfonate. The new sand-fixation dust suppression agent has improved compressive strength and a longer degradation cycle, so it is more conducive to practical application.