Study On Quaternization Of Cellulose-g-poly[2-(Dimethylamino) Ethyl Methacrylate] And Application In Adsorption For Methyl Orange

Pollution caused by dye wastewater has become one of the most serious environmental problems in the world.Treatment of dye wastewater with adsorbent has attracted more and more attention due to its good adsorption effect,low cost,reproducibility and so on.And with the improvement of environmental protection consciousness,environmentally friendly natural materials have become one of the ideal raw materials for dye adsorbent synthesis.In this paper,free radical-initiated graft polymerization of(2-methacryloyloxyethyl)trimethyl ammonium chloride(DMC)from microcrystalline cellulose was studied.Influence of reaction condition,such as initiation system(e.g.potassium persulfate,ammonium persulfate,ceric ammonium nitrate,potassium persulfate-sodium bisulfite,benzoyl peroxide),reaction temperature(45?,50?,55?,60?,65?),initiator concentration,initiation time(15 min,20 min,25 min,30 min,35 min)and monomer dosage(0.5 mL,1 mL,2 mL,3 mL,4 mL)for 0.5 g microcrystalline cellulose,on grafting percentage and grafting efficiency has been investigated,showing relatively low grafting percentage,grafting efficiency as well as cationic degree.To achieve cationic cellulose-based copolymer with higher grafting percentage,potassium persulfate(KPS)-initiated graft polymerization of 2-(dimethylamino)ethyl methacrylate(DMAEMA)from microcrystalline cellulose and subsequent quaternization with methyl iodide has been carried out.Thus prepared quaternized cellulose-graft-poly[2-(dimethylamino)ethyl methacrylate](QD-Cell-g-PDMAEMA)has also been verified with FT-IR,scanning electron microscopy(SEM),13C-NMR and thermogravimetric analysis.In addition,adsorption properties of QD-Cell-g-PDMAEMA for methyl orange(MO)from aqueous solution were studied.Experimental results showed that grafting percentage as high as 65.1%could be achieved when amount of microcrystalline cellulose was 0.5 g,initiator concentration was 3.6 g/L and dosage of monomer was 3 mL with reaction time being 5 h at 35?.On quaternization with molar ratio of methyl iodide to tertiary amino group being 4:1 at 35?,quaternization degree could be enhanced to 58.3%,equivalent to 38%of grafting percentage for graft polymerization of(2-methacryloyloxyethyl)trimethyl ammonium chloride(DMC)from cellulose,35.7%higher than that for similar graft polymerization in reference.Experimental results indicated that QD-Cell-g-PDMAEMA could afford satisfactory removal efficiency for methyl orange from aqueous effluents when the pH was between 3-10.For instance,maximum removal efficiency of 99.30%could be attained at pH 6.97,while removal efficiency of 89.26%could be maintained at pH 10.00.Further investigation showed that kinetic adsorption of QD-Cell-g-PDMAEMA for MO followed pseudo-second,order model and adsorption isotherms fitted well with Langmuir model,from which maximal adsorption capacity could be derived as 135.01 mg g-1 for MO.Compared with graft polymerization of DMC from cellulose,it can be concluded that graft polymerization of DMAEMA and subsequent quaternization with methyl iodide render an effective approach to prepare efficient adsorbent for anionic contaminants from wastewater.