羧甲基纤维素三元共聚物的制备及性能OA

Conventional crude oil demetallizing agents have prominent drawbacks including strong corrosiveness and poor environmental compatibility.These defects not only corrode refining equipment but also bring hidden environmental pollution hazards,which greatly restrict their long-term service in petroleum processing.To solve the above problems and synthesize a new demetallizing agent with high metal removal rate,low corrosivity,and eco-friendliness,biodegradable natural polysaccharide carboxymethyl cellulose(CMC)was adopted as the polymer matrix in this work.Acrylamide(AM)and hydroxyethyl acrylate(HEA)were chosen as copolymer monomers,and the ternary graft copolymer CMC-HEA-AM was successfully prepared through free radical graft copolymerization.The synthesized CMC-HEA-AM was characterized by FTIR,SEM and TG.The influencing factors of the copolymerization reaction,thermal stability,and metal removal ability of the product were systematically explored.Experimental results show that under the conditions of the molar ratio n(CMC)∶n(HEA)∶n(AM)of 1∶1∶4,reaction temperature of 85℃,ammonium persulfate and isopropanol amounts of 7%(w),and the reaction time of 3 h,the conversion of AM and the yield of CMC-HEA-AM reach 86.26%and 91.42%,respectively.When the demetallization temperature increases to 120℃,the removal rates of calcium,vanadium,and nickel are 84.96%,37.21%,and 31.61%,respectively,with the highest removal rate obtained in calcium.It proves that CMC-HEA-AM possesses excellent metal removal ability as a crude oil demetallizing agent.Ester groups and amide groups are successfully grafted onto the main chain of CMC copolymer.These functional groups are the key to efficient chelation with metal ions.The copolymer possesses a compact,stable structure that is not prone to collapse,which lays a reliable structural basis for crude oil demetallization.Moreover,comparison of metal removal rates between raw CMC and CMC-HEA-AM confirms that the ternary copolymer has remarkably improved chelating activity relative to pure CMC.Preliminary analysis on its chelation mechanism further verifies the promotion of metal chelating capacity after graft modification.All test data manifest that the prepared demetallizing agent has favorable metal ion selectivity and high demetallization efficiency,especially superior calcium removal ability.In conclusion,the CMC-HEA-AM terpolymer shows outstanding demetallization performance in crude oil pretreatment and can remove metallic impurities efficiently under mild reaction conditions.In addition,the material features low corrosivity and environmental friendliness,which perfectly makes up for the deficiencies of traditional demetallizing agents.Therefore,this novel graft copolymer has high application value and wide development prospects in the field of crude oil pretreatment.