Preparation And Application Study On Amino Acid-modified Chitosan-based Resin

For improving deacetylation degree?D.D?,chitosan raw material was put in the 10 mol/L NaOH,reaction time was 4h,temperature was 110?,and the D.D was up to 86.4%.Then,It was discussed the influence of chitosan D.D on.Dadsorption capacity for Cu²⁺ and Ni²⁺.The results showed that chitosan has the better adsorption capacity of the two kinds of heavy metal ions,with the increase of the D.D.In addition,Then batch tests were carried out to investigate the adsorption performance of chitosan?D.D=86.4%?.It was found the removal rate can reach maximum,when chitosan was 1.5g.Moreover,the removal rate increased linearly before 10 minutes,and tended to the balance after 20minutes.Finally,the removal rate of chitosan to Cu²⁺and Ni²⁺ was 58.94%and 50.21%without selectivity,which was much higher than that of zeolite,activated carbon and diatomite.For improving the heavy metal ion adsorbability,of chitosan?CS?,L-arginine?L-Arg?was immobilized on CS molecules,in presence of condensing agent 1-?3-Dimethylaminopropyl?-3-ethylcarbodiimide hydrochloride?EDC?and coupling reagent N-Hydroxysuccinimide?NHS?,using chitosan as a matrix,to prepare a new kind of natural-macromolecular-based heavy metal ion chelating material,L-arginine GRafted Chitosan?CA?.Select the optimal process by single factors and 3 factors 3 levels orthogonal experiments.The structural composition of product was characterized by FT-IR?RAM?XRD?13CNMR and SEM.The results showed when the molar ratio of reagent was nCS:nArg:nEDC =1:1:1,nEDC:nNHS=1:1,reaction time was 12 hours,pH=5.5,the GRating ratio?GR?was up to 17.05%.The results of adsorption experiments showed CA?G=17.05%?had higher removal of Cu²⁺ and Ni²⁺ ion than CS,and adsorption conforms to the quasi level 2 dynamic model,in line with the Langmuir adsorption process isothermal adsorption model,also in line with the Freundlich isothermal adsorption model.There were large amounts of hydrogen bond,amino and some acylamino ect,which were electronegative groups in the CA molecular chain.There were also a lot of intramolecular hydrogen bond and intermolecular hydrogen bond,so CA has excellent film-forming ability.Select the optimal process by using 2%of ice acetic acid as solvent to dissolve 5%of CA,10g/L sorbitol as plasticizer.The next,it maked a selection to polyester film as substrate in the scraping membrane method.Under the optimum process,the thickness of film was 0.03mm,the intension was 715cN,the removarate of Cu²⁺ and Ni²⁺ was 74.53%and 69.42%,and the inhibition rate of e.coli and S.aureus was 90.23%and 93.37%.