Preparation And Oil Adsorption Of Cellulose-graft-poly(butyl Acrylate-N,N’-methylene Bisacrylamide)

In the past decades,oil and organic solvent leakages occurred more frequently.Oil pollution caused by leakages brings great harm to quality of air,water and soil,affecting the survival of animals and plants,and also affecting human health.In addition,weathering can change the density,viscosity and other properties of oil,making it more challenging to treat pollution.At present,researchers have developed various oil pollution treatment methods,which can be mainly divided into four categories:physical method,chemical method,biological method,and in-situ burning method.Among them,the use of oil sorbents in physical method to treat oil pollution is more economical and environmentally friendly,and can remove oil slicks from water more thoroughly.Therefore,oil sorbents have become one of research hotspots of oil pollution treatment.Cellulose has a wide range of sources,with low cost,good biodegradability,biocompatibility,and mechanical properties.Cellulose shows low adsorption capacity when it is directly used for oil absorption.However,the oil absorption performance of cellulose can be significantly improved by grafting copolymerization of lipophilic monomers and constructing cross-linked three-dimensional network structures on the surface of cellulose.In this paper,using microcrystalline cellulose as substrate,benzoyl peroxide(BPO)as initiator,butyl acrylate(BA)and N,N’-methylene bisacrylamide(MBA)as grafting monomer,cellulose-graft-poly(butyl acrylate-N,N’-methylene bisacrylamide)[Cell-g-P(BA-MBA)]has been prepared by radical graft polymerization.The chemical structure,elemental composition,surface morphology and wettability of the graft polymerization product were characterized by infrared spectroscopy,elemental analysis,scanning electron microscopy,and contact angle test.The results indicated that hydrophobic Cell-g-P(BA-MBA)had been prepared successfully.Firstly,influence of the dosage of initiator BPO and monomer BA on grafting percentage and grafting efficiency of cellulose-graft-poly(butyl acrylate)(Cell-g-PBA)was investigated.The grafting percentage and grafting efficiency would increase first and then decrease,corresponding to increasing dosage of initiator BPO and monomer BA.When the dosage of microcrystalline cellulose was 1.00 g,initiator BPO was 0.20 g,and the monomer BA was 6.00 g,grafting percentage and grafting efficiency of Cell-g-PBA reached the highest as 432.00%and 72.67%respectively.Influence of dosage of BPO,MBA,BA,and graft polymerization temperature on oil absorption capacity of Cell-g-P(BA-MBA)were investigated by orthogonal test when the mass of microcrystalline cellulose was maintained as 1.00 g.Experimental results showed that order of influences follows grafting polymerization temperature>MBA>BPO>BA.Based on orthogonal test results,procedure for grafting polymerization was optimized.When grafting polymerization temperature was 70℃,dosage of MBA was 0.35 wt%of BA,BPO was 0.09 g,and BA was 7.00 g,the maximum adsorption capacity of thus prepared Cell-g-P(BA-MBA)for chloroform,toluene,92#gasoline,and 0#diesel was 37.55 g g-1,18.72 g g-1,10.45 g g-1,and 0.71 g g-1,respectively.In addition,adsorption capacity of Cell-g-P(BA-MBA)for different organic solvents and oils was further tested.The adsorption capacity of Cell-g-P(BA-MBA)for chloroform,toluene,acetone,N,N-dimethylformamide,and 92#gasoline was 37.55 g g-1,18.72 g g-1,9.46 g g-1,7.37 g g-1,and 10.41 g g-1,respectively.The adsorption capacity of n-hexane,0#diesel oil,soybean oil,engine oil,and vacuum pump oil was between 0.54 g g-1 and 0.90 g g-1.Compared with other similar oil sorbents,Cell-g-P(BA-MBA)has a higher adsorption capacity for various organic solvents.Furthermore,the adsorption kinetics,adsorption isothermal model,adsorption thermodynamics,oil-water separation,and regeneration of Cell-g-P(BA-MBA)were investigated.Experimental results showed that adsorption process exists physical adsorption,which is spontaneous and exothermic,and that adsorption isotherm fits Freundlich isotherm adsorption model.Cell-g-P(BA-MBA)can quickly remove the oil slick on the water surface,and its adsorption capacity remains unchanged after 15 adsorption and desorption cycles.In conclusion,cellulose-based graft polymer Cell-g-P(BA-MBA)prepared in this paper is a renewable and efficient oil sorbents,showing great application potential for treating oil pollution in water.