Study On Preparation And Properties Of Double Matrixsuper Absorbent

Because of its special internal structure,the superabsorbent resin has excellent water-absorbing properties and the ability to adsorb heavy metals.Therefore,the water-absorbent resin is widely used in agriculture,forestry,water conservation,and thepurification of heavy metal wastewater.At present,In the field of high water-absorbing resins,the main focus is on the research of single matrix water-absorbent resins,and their salt resistance needs to be improved.In order to improve the water absorption and salt resistance of the water absorbing resin,a double matrix water absorbing resin is prepared in this paper.The double matrix absorbent resin research has very important significance and application value.In this thesis,P(SA/CMS-Na/AA)and P(XG/CMS-Na/AA)superabsorbent resin were synthesized by aqueous solution polymerization with sodium alginate(SA),xanthan gum(XG),sodium carboxymethyl starch(CMS-Na)as the matrix,acrylic acid(AA)as the monomer,ammonium persulfate(NPS)andN-N'methylene bisacrylamide(MBA)asinitiator and cross-linking agent.The results showed that when the wt(MBA)= 0.025%,wt(NPS)= 0.3%,wt(CMS-Na)= 5%,wt(SA)= 1.5%,AA neutralization was 70%,reaction temperature T=65 ?,P(SA/CMS-Na/AA)super absorbent resin water absorption effect is better.The ratio of deionized water and 0.9% NaCl solution was 2308.48 g/g and 126.8 g/g.when the wt(MBA)= 0.03%,wt(NPS)= 0.2%,wt(CMS-Na)= 6%,wt(SA)= 1.5%,AA neutralization was 60%,reaction temperature T=65 ?,P(XG/CMS-Na/AA)super absorbent resin water absorption effect is better.The ratio of deionized water and 0.9% NaCl solution was 2308.48 g/g and 126.8 g/g.The water-absorbent resin was characterized via FTIR and SEM.FTIR indicates that AA is graft copolymerized with two substrates.SEM indicates that two superabsorbent resins are a porous cross-linked material.The best pH range for P(XG/CMS-Na/AA)superabsorbent was 4~9 and best pH range for P(SA/CMS-Na/AA)superabsorbent was 5~8.Two water-absorbent resin still have a good water absorption capability after repeatedly absorbing water for 3 times.The maximum soil moisture retention rate can be increased by 57% when the amount of P(SA/CMS-Na/AA)superabsorbent resin in the soil was 0.2%.The maximum soil moisture retention rate can be increased by 53% when the amount of P(XG/CMS-Na/AA)superabsorbent resin in the soil was 0.2%.The lead ions and cadmiumions adsorption dynamics studies indicated that the adsorption of cadmium and lead ions was in accordance with the quasi-second order kinetic model and the adsorption belongs to chemical adsorption.The thermodynamics studies indicated that the adsorption of cadmium and lead ions was in accordance with Langmuir model and the adsorption belongs to monolayer adsorption.The adsorption process was spontaneous exothermic reaction...