Preparation Of PDA Under Microwave And Its Application

DMDAAC with AM copolymer referred to as PDA. It has high charge density,stability of the molecular structure, good solubility in water, efficient, non-toxic,beable to adapt to a wide range of pH. and so on. It is widely used in mining, householdchemicals,oil, textile and water treat ment and other fields. As early as the1950s,foreign studied on PDA and put into industrial production,Although China has its industrialized production, our products still exist acertain gap in performance and applications, compared with similar foreign products.In this study, we use (NH4)S2O8as an initiator and microwave to product PDA.The optimum conditions of polymerization were obtained as follows：The microwavetime is1.5min, the DMDAAC/AM was4:16, the dosage of (NH4)S2O8is0.5‰, thedosage of EDTA was0.3‰., the dosage of urea is0.2‰, the reaction time was4.0h,the temperature is40℃, the pH value was was2.0. Under these conditions, the PDAwith intrinsic viscosity was4.89dL/g, the dissolution time is2.5h.IR and NMR prove our products have the same bonds and groups with monomerAM and monomer DMD, it determine our products were a copolymer of monomer AMand monomer DMD. SEM analysis showed that the polymer PDA. SEM analysisshowed that t surface of PDA is roughness,uneven and have many pores, with a largesurface area, this makes it stronger adsorption and bridging ability than similarpolymers. Its unique structure makes it can absorb the water column particulatepollutants more powerfully, to clean up pollutants in water bodies more thoroughly.PDA could not be decomposed at room temperature proved by DTA-TGA analysis.The pond water was treated with PDA. The results suggested PDA couldeffectively reduce water turbidity and UV254.The optimum conditions of flocculationwere obtained as follows: the dosage of PDA is2mg/L, the fast stirring speed is280r/min, the slowly stirring time is12min, the standing time is25min. Combine PDAwith PAC to treat the pond water is very well, when the dosage of PAC is30mg/L, thedosage of PDA is2mg/L, the turbidity dropped less than1.0NNTU, meeting thenational drinking water standards on turbidity, producing larger flocs, the separated water is more clear. And the removal rate of UV254is up to73%.Phenol was treated with PDA. The results suggested PDA could effectivelyremoval the Phenol, and removal of Phenol up to99.9%. During the experiment alsofound that the removal of phenol is also related to the initial concentration ofphenol,experiments show that the lower the initial concentration of phenol, the higherremoval it will have.