Abstract:
Amino-terminal hyperbranchedpolymer(HBP-NH
2) was synthesized by polycondensation.Carboxylatednanocellulose(CNC) was prepared from eucalyptus pulp by using ultrasonic assisted 2, 2, 6, 6-tetramethylpiperidinyl-1-oxy (TEMPO)radical oxidation, and dialdehyde-based nanocellulose(DNC) was further obtained by sodium periodate oxidation of CNC. Finally, the amino-terminated hyperbranched polymer grafted dialdehyde-basednanocellulosematerial(HBPN-DNC) was prepared by amination modification of DNC with HBP-NH
2. The reaction conditions were optimized. When the addition of 10% HBP-NH
2 solution was 10 mL, the reaction temperature was 70℃, and the reaction time was 4 h, the N element mass fraction reached the highest, 6.0%. The structure and properties of nanocellulose were characterized by various methods. The results showed that the amino group was successfully graftedonto DNC. The molecular chain became longer and the thermal stability of the HBPN-DNC improved.The adsorption properties of Ni
2+ on HBPN-DNC showed that, under the conditions of room temperature, 0.1 g of HBPN-DNC adsorbent, initial mass concentration of adsorption solution of 500 mg/L, pH value of 5 and adsorption time of 3 h, the adsorption capacity was 150.21 mg/g. The adsorptionfollowed the pseudo second order kineticsequation and Langmiur adsorption isotherm, which indicated that the adsorption process was mainly chemical adsorption of single molecular layer.