Study on the flocculating properties of quaternized carboxymethyl chitosan

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摘要：

Quaternized carboxymethyl chitosan (QCMC) was prepared through the grafting reaction of carboxymethyl chitosan (CMC) with 3-chloro-2-hydroxypropyl trimethylammonium chloride (CTA) as a quaternizing agent in 2-propanol medium under basic condition. The synthetic conditions for QCMC were as follows: 40.0% of NaOH aqueous solution as catalyst; reaction temperature, 60.0°C and reaction time, 10.0h; NaOH/CMC, 0.50; CTA/CMC, 1.50 (mass ratio). The characterization by FT-IR and 1 H NMR demonstrated that QCMC was a typical amphoteric chitosan derivative in which the carboxymethyl group and the quaternary ammonium group were both introduced into the chitosan molecular chain. QCMC was applied to flocculate a simulated wastewater containing 40.15mg/L Cd(II) or 15.62mg/L Cr(VI) respectively. The results indicated that the appropriate pH value for removal of Cd(II) and Cr(VI) were ca 8.5 and 5.0, and the appropriate corresponding mass concentrations of QCMC was 140 mg/L and 120.0 mg/L , respectively. Under these conditions, the removal ratio of Cd(II) and Cr(VI) may reach 99.7% and 94.4% , respectively.

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PLGA-PEG-PLGA in-situ gelation peptide delivery thermo-responsive drug delivery calcitonin biodegradable polymers

DOI：

10.1007/s00289-007-0801-x

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年份：

2007