Natural polymers chelating properties

Knowledge about natural metal chelates induced in the first stage researdi work for artificial low molecular metal dielates. Secondly experience about the important environmental effect of natural polymers like apoprotein lead to research on the combination of synthetic polymers with a metal chelate. By intensive investigation in these fields new combinations of metal dielate/polymer may be found, even with unknown properties. 

Polyvinylpyrrolidone is thus utilized as either aqueous or organic solutions in a multitude of applications. Many of these applications are also related to the chelating properties of this polymer. Thus, it forms complexes with molecular iodine (I2) and can thus be used as a reservoir of this molecule whose disinfecting properties are well known. It also gives strong interactions with natural and synthetic dyes and thus facilitates their anchoring on textile fibers by complexation with the corresponding polymers. 

Bailar listed a number of principles that can be considered in designing coordination polymers as follows (1) Little flexibility is imparted by the metal ion or within its immediate environment thus, flexibility must arise from the organic moiety. Flexibility increases as the covalent nature of metal-ligand bond increases. (2) Metal ions only stabilize ligands in their immediate vicinity thus, the chelates should be strong and close to the metal ions. (3) Thermal, oxidative, and hydrolytic stabilities are not directly related polymers must be designed specifically for the properties desired. (4) Metal-ligand bonds have sufficient ionic character... 

They comprise a comparison of the activities of polymeric phthalocyanines with various central atoms. The monomers always showed lower activity than the corresponding polymers. The nature of the substrate has a decisive influence on the catalytic properties of the chelate. Electrodes with gold substrate showed only very slight activity. 

PROPERTIES OF SPECIAL INTEREST Natural resources basic polysaccharides nontoxic biodegradability bioactivity biosynthesis interesting derivatives (chitosan) toughness graft copolymerization chelating ability for transition metal cations immobilizes enzymes by chemical linking or adsorption chiral polymer. 

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