Grafting of O-Carboxymethyl Chitosan with Acrylonitrile and Studying some of its Properties and Applications

Preparation of o-carboxymethyl Chitosan was done, wich is important derivative of chitosan. Grafting copolymerization of acrylonitrile onto o-carboxymethyl chitosan was accomplished using ammonium cerium sulfate (CAS) as an initiator. Resulting graft of o-carboxymethyl chitosan was characterized by FT-IR spectrum and DTA analysis to be compared with o-carboxymethyl chitosan. Properties such as water swelling and solubility were studied for each, whereas,. Percentage of grafting efficiency (GE%) and yield of grafting (GY%) were determined. The efficiency of grafted ocarboxymethyl chitosan (CMCh-g-PAN) to remove dyes(direct black dyes, dispersed red dyes) from industrial waste water was also determined. The results reveal good efficient absorption of black dyes more than red dyes. Efficiency from different concentrations of grafted o-carboxymethyl chitosan(CMCh-g-PAN) to reveal percentages of elimination ions from their solutions metallic ions Cu2+,Pb2+,Cd2+and Sn2+ from their solutions at room temperature with mechanical stirring for 24 hrs were also determined .It has been shown that grafted o-carboxymethyl chitosan has important role in elimination of lead ion comparing with other ions, As a result, elimination percentages of ions increase as follow: Cd2+< Sn2+< Cu2+<. Pb2+

The use of cerimetric method for phenolic hydroxyl determination in analytical practice

The possibility of using cerium (IV) sulfate as an oxidizing reagent in analysis of various organic compounds is considered and exemplified specifically in determination of phenolic hydroxyl group. Cerium sulfate quantitatively reacts with a phenolic hydroxyl group to form quinoid compounds. Techniques for determination of phenols of different structures (including perchlorinated and perfluorinated phenols) using potentiometric titration with a solution of cerium sulfate in a sulfuric acid medium with a redoxometric indicator electrode are proposed. The presence of the substituents with reducing properties in the aromatic ring interferes with the determination. Cerimetric potentiometric titration was also used to study the structure of polymers based on methylol derivatives of phenolphthalein which are crosslinking agents and serve to obtain thermostatic structural materials with high strength properties. It is shown that the methylol hydroxyl group, which is also quantitatively oxidized by cerium sulfate, can be determined simultaneously with a phenolic hydroxyl group. The results obtained by the proposed method of cerimetric titration and well-known method of acetylation appeared identical. The determined number of hydroxyl groups in the analyzed samples is indicative of the polymer structure. Proceeding from the technique of cerimetric titration we propose a method for determination of free xylenols in fire-resistant turbine oil. The developed technique is more rapid and less labor-consuming compared to generally accepted technique TU 3470.11335–07 based on the bromination of xylenols with a bromide-bromate mixture.