The Preparation And Performances Of The Modified Carboxymethyl Cellulose/Carboxymethyl Starch Dust Suppressans

With the rapid economic development,our country’s natural environment has suffered a certain degree of damage.In recent years,due to the influence of dust and other pollution,severe haze weather has appeared in most parts of the country,which has caused great impact on people’s health and transportation,and has caused people of all walks of life to pay close attention to the problem of dust pollution.Coal dust generated during coal transportation also belongs to dust pollution,which not only seriously affects the normal growth of road surrounding environment and vegetation,but also causes great waste of coal resources.The main solutions include the cover tarpaulin method,the sprinkler method,and the chemical dust suppression method,among which the chemical dust suppression method has better dust suppression effect in the coal transportation process.The environment-friendly multifunctional polymer dust suppressor is the main R&D direction of chemical dust suppressants in recent years,but currently the polymer-based dust suppressants marketed are mostly “hard shell type’’,and this dust suppression agent is easily transported in vehicles.In the process,the impact is caused by the vibration,resulting in the failure of the dust suppression agent.Therefore,the development of a “soft film type” dust suppression agent with excellent dust suppression performance has great application prospects.In the preparation of soft membrane type dust suppression agent,first with carboxymethyl cellulose as the main raw material,acrylic acid,acrylamide as graft monomer,under the condition of microwave radiation,the preparation of carboxymethyl cellulose/acrylic acid/acrylamide type dust suppression agent.In order to increase the solution stability and film flexibility of the resulting product,Surfactant or plasticizers were added during the experiment.Then the monomer ratio,the amount of initiator,the amount of surfactant and plasticizer,the polymerization temperature and the polymerization time were discussed.The structure of the product was characterized and analyzed by Fourier infrared spectroscopy,thermogravimetric analysis and scanning electron microscopy.And test its water retention,wind erosion resistance,shock resistance,temperature adaptability andpressure resistance.Finally,the optimum synthesis process of the modified carboxymethyl cellulose dust suppressor was determined as follows: m(AA):m(AM)was 1:2,and the neutralization degree of acrylic acid was 60.0%.The agent is 1.0% of the total mass of the monomer(same below),the amount of cross-linking agent is 0.5%,the amount of plasticizer is 20.0%,the amount of surfactant is 6.0%,the polymerization temperature is 70°C,reaction time is 15 min,microwave power 500 w.The prepared dust suppressant film has a certain strength and toughness,and its average elongation at break is 342.8%,the pulverized coal sprayed with the dust suppressant solution is placed at 25°C.for 40 hours and the coal powder still has a moisture content of 4.75%.The water content of pulverized coal in water is only0.44%.The loss rate of pulverized coal sprayed with dust suppressant solution is only 5.40%after continuous purging for 3 hours,and the pulverized coal sprayed with water is up to61.50%,resulting in a large amount of pulverized coal loss,The loss rate of pulverized coal sprayed with dust suppression agent solution was only 6.36%,while the spraying water reached 57.64%,indicating that the dust suppression agent has good water retention,wind erosion resistance,and anti-shock performance.Using carboxymethyl starch as the main raw material and acrylic acid and acrylamide as grafting monomers,carboxymethyl starch/acrylic acid/acrylamide-type dust suppressants were synthesized under microwave irradiation.Through the microwave reaction process conditions,product structure characterization and analysis and application of performance testing.The results show that when m(AA):m(AM)= 1:4,the initiator dosage is 1.0%,the cross-linking agent dosage is 0.5%,microwave reaction time,temperature and power are15 min,65°C,and 500 W respectively.The water retention rate of the dust suppression agent prepared after being placed at 25°C for 40 h is still 4.83%.The loss rate of coal powder is only 0.61% after continuous purging for 3h,and the loss rate for pulverized coal is only3.60% after 40 h of vortexing,The compressive strength of the pulverized coal model was greater than 0.02 MPa between-20°C and 60°C,indicating that the carboxymethyl starch/acrylic acid/acrylamide dust suppressant also has good water retention,wind erosion resistance,shock resistance,and temperature Adaptability and compression resistance.