title: Synthesis and applications of chitosan mercaptanes as heavy metal retention agent.
abstract: Chitosan, poly-beta(1-->4)-2 amino-2-deoxy-D-Glucopyranose is a biopolymer obtained by extensive deacetylation of chitin [poly-beta(1-->4)-2-acetamide-2-deoxy-D-Glucopyranose], main constituent of crustacean shells. The present study was carried out using crab shells from nylon shrimps (Heterocarpus reedi). Despite the abundance of raw material in our environment, little work has been published in this field using derivatives. The main goal of this work is to develop a good method to prepare chitosan mercaptanes derivatives using mercaptoacetic acid and 1-chloro-2,3-epoxy propane propionic acid. The evaluation of the retention capacities using several concentrations of copper and mercury solutions with concentrations ranging from 10 to 104 ppm at pH 2.5 and 4.5 are tested. A comparison of the absorption isotherms with Langmuir isotherms is also reported. Full characterization of the derivatives was carried out using FTIR, elemental analysis and TGA. The morphology of chitosan and derivatives is compared before and after treating polymers with mercury and copper ions.
authors.affiliation: Departamento de Polímeros, Universidad de Concepción, Facultad de Ciencias Químicas, Casilla 160-C, Concepción, Chile. gcardena@udec.cl
authors.forename: G
authors.initials: G
authors.lastname: Cárdenas
authors.forename: P
authors.initials: P
authors.lastname: Orlando
authors.forename: T
authors.initials: T
authors.lastname: Edelio
mesh_terms: D000327:Adsorption; D000818:Animals; D002686:Chitin / Q000031:analogs & derivatives / Q000737:chemistry*; D048271:Chitosan; D003300:Copper / Q000737:chemistry; D033364:Decapoda / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007477:Ions; D008628:Mercury / Q000737:chemistry; D019216:Metals, Heavy / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D008956:Models, Chemical; D011108:Polymers / Q000737:chemistry; D011422:Propionates / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D013864:Thioglycolates / Q000737:chemistry
chemical_list: D007477:Ions; D019216:Metals, Heavy; D011108:Polymers; D011422:Propionates; D013864:Thioglycolates; D002686:Chitin; C017487:2-mercaptoacetate; D003300:Copper; D048271:Chitosan; D008628:Mercury; C029658:propionic acid