New Technology for the Synthesis of New Materials Based on Cellulose and Sorption of Noble Metals

This experiment was performed with a sample of powdered microcrystalline cellulose form Aldrich company.Before using the cellulose, powder was subsequently rinsed with water, ethanol, methanol and acetone, and then dried at 50°C.Parameters important for optimization of the synthesis of cellulose acrylate and that were considered were: molar ratio of reactants in reaction mixture of cellulose/potassium-t-butoxide/acryloyl chloride = 1:3:10, and different synthesis reaction times of cellulose acrylate of 1,3,5,8 and 10 hours.Cellulose acrylate and grafted cellulose copolymers with 4-vinylpyridine, 1-vinylimidazole, 1-vinyl-2-pyrrolidone and 9-vinylkarbazole were synthesized according the methods and procedures described by (Bojanic, 1994(Bojanic, , 2010)).Cellulose acrylate (Cell-acrylate) was synthesized by making 3.24 g-0,02 mol of cellulose swell in 50 ml of acetonitrile for one hour at room temperature.Potassium-t-butoxide 6.72 g-0.06 mol was dissolved with mild heating in 50 ml of acetonitrile and the reaction with the cellulose solution at room temperature, with mixing, during 4 hours took place.Formed potassium-cellulosate was not isolated, and overplus of acryloyl chloride was added in it, namely 18g-0.2mol in 50 ml of acetonitrile at 25 0 C. Reaction mixture was mixed and refluxed during 10 hours.Cellulose acrylate was then washed with water, ethanol, methanol and acetone and dried at 50 0 C. 4.65 g of product was obtained which has a band at 1720 cm -1 from ester carbonyls in IR-spectrum in KBr.Elemental analysis of samples taken after 1, 3, 5, 8, 10 hours provides optimum time of 10 hours.During this period, the reaction gave a product with a degree of substitution (DS) of 2.4.The same procedure was repeated for lignin and tannin, with the difference that instead of cellulose the same weight amount of lignin and tannin was taken.The only difference is that the tannin acrylate was not elutriated with water because it is being dissolved in it.The resulting tannine acrylate and lignin acrylate have characteristic band at 1720 cm -1 in the IRwww.intechopen.comNew Technology for the Synthesis of New Materials Based on Cellulose and Sorption of Noble Metals 181 spectrum.Synthesis of cellulose poly-4-vinylpyridine (PVP-Cell) was performed as follows: Grafting of 4-vinylpyridine on cellulose acrylate was done by adding 1 g-0.0046mol of acrylate cellulose, 5ml-4,88g-0,046 mol of 4-vinylpyridine and 0.05 g azobisisobutyronitrile (AIBN) in 50 ml of acetonitrile.Reaction mixture was mixed and refluxed for 5 hours in a stream of nitrogen.1,1g of Cell-PVP was obtained, and it was characterized by IR spectroscopy with characteristic IR-spectrum bands at 1620, 990 and 820 cm -1 .Sorption of gold after 1 and 24 hours was 98.12 and 99.63 wt.%.The capacity was 0.2 g Au/g ionexchanger.In comparison, the capacity for Pd and Pt is about 0.03 g/g ion-exchanger.Synthesis of lignin poly-4-vinylpyridine (Lig-PVP) was performed as follows: the procedure was the same as for the synthesis of Cell-PVP, but instead of cellulose, 1g of lignin was taken.1,1g Lig-PVP was obtained, and it was characterized by IR spectroscopy with characteristic IR-spectrum bands at 1620, 990 and 820 cm -1 .Obtained Lig-PVP does not swell in water.However, in a solution containing Au, Pd and Pt ions, it swelled 100 wt%.Sorption of Au was fast and complete and the capacity was 0.211 g Au/g ion-exchanger.This capacity was confirmed in the strong acidic electrolytes in which both Pt and Pd are present.Regeneration with HCl (1:1) was complete.By checking the capacity with 0.1 M solution of Au it was noticed that the yield was 0.4 g Au/g ion-exchanger.The sorption of platinum metals was studied as well, and it was very good.Synthesis of tannine poly-4-vinylpyridine (Tan-PVP) was performed as follows: the procedure was the same as for the synthesis of Cell-PVP, but instead of cellulose, 1g of tannine was taken.1.1g of Tan-PVP was obtained, and it was characterized by IR spectroscopy with characteristic IR-spectrum bands at 1620, 990 and 820 cm -1 .Sorption of Au for Tan-PVP has not been tested because it is soluble in water.www.intechopen.com