Preparation and Applications of Some Chitosan Derivatives

1. Preparation and Applications of Some Chitosan Derivatives by Mohamed Abdel Tawab Sayed

2. Outlines 1-Introduction a) General Background b) Aim of the work. 2-Experimental Preparation of Chitosan. Synthesis of the two polymer ligands Synthesis of the metal complexes

3. 3 - Results and Discussion Part I) Characterization of the polymer ligands and their metal complexes Part II) Thermal Gravimetric Analysis (TGA) and Thermodynamic Parameters Part III) Metal uptake 4- Conclusions

4. Introduction

5. a) General Background • Chitosan and their derivatives have various potential applications on metal removal from waste waters • Chitosan polymer derivatives containing oxygen, and/or sulfur as coordinating sites gave rich and valuable knowledge in coordination chemistry. • Chitosan derivatives are considered important examples of ligands that have significant metal uptake for transition metals, such as: Co(II), Ni(II), Cu(II), Fe(III) and Cr(III)

6. Reaction of Chitosan with Cinnamoyl chloride and/or ammonium thiocyanate/Cinnamoyl chloride gave the corresponding Chitosan polymer ligands

7. Aim of the work Synthesis of two polymeric chitosan derivatives from the reaction of chitosan with either cinnamoyl chloride or ammonium thiocyanate/cinnamoyl chloride. Synthesis of transition metal complexes of the synthesized ligands Elucidation of the geometrical structures of the synthesized complexes. Study the thermal stability and thermodynamic parameters of the prepared solid complexes. Using the synthesized ligands for the metal uptake to remove Cu(II), Ni(II), Co(II), Cr(III) and Fe(III) from their aqueous solutions

8. Experimental Preparation of Chitosan 1- Extraction of Chitin from local source (Shrimps). a) Demineralization with 1.0 M HCl. b) Deproteination with 1.0 M NaOH at 80-85ºC. 2- Deacetylation of Chitin into Chitosan. a) Reflux with 40-50 % NaOH for 20 hrs. b) Filtration and washing with water till neutrality. c) Boiling with EtOH for 6 hrs, then filtration and drying.

9. Synthesis of the Chitosan polymer ligands 1-Formation of the (ChitoCin) Polymer

10. O O CH CN N C S Cl 3 NH SCN + 4 C H O H O 2 O H O N H 2 n C H O H O 2 O H O N H S N H O n 2- Formation of the (ChitoThioCin) Polymer.

11. Reflux Methanol 2 - 4 hrs Synthesis of Metal Complexes ChitoCin or ChitoThioCin M2+ or M3+ Complexes + M2+ = Cu(II), Ni(II), Co(II) M3+ = Fe(III) or Cr(III)

12. Characterization of the Chitosan ligands and their metal complexes

13. The used techniques are: • Elemental (C, H, N and S) analyses. • Metal ions analyses using EDTA • Infrared spectra • Electronic spectra • ESR spectra • Magnetic measurements • Thermal gravimetric analysis (TGA) • Melting points

14. Results and Discussion

15. Part (I): Characterization of the polymer ligands and their metal complexes

16. A) Infrared Spectra of polymer ligands ChitoCin polymer ligand Cinnamoyl chloride Chitosan ChitoCin

17. ChitoThioCin polymer ligand NH4SCN Cinnamoyl chloride Chitosan ChitoThioCin

18. ChitoThioCin ChitoCin B) Electronic Spectra of polymer ligands

19. TGA-DrTGA curve of ChitoCin TGA-DrTGA curve of ChitoThioCin C) TGA analysis of polymer ligands

20. Metal Complexes of the Chitosan Ligands

21. A) Physical and analytical data for the ChitoCin and ChitoThioCin polymers and their metal complexes.

22. B) Infrared Spectra of the metal complexes

23. Cont. Infrared spectra of the metal complexes • Disappearance of the band assigned to (C=O) of the ChitoCin free ligand and appearing of a new band (C-O) in its metal complexes. • Appearance ofAzomethine (C=N) in ChitoCin metal complexes. • Disappearance of the band assigned to (C=S) of the ChitoThioCin and appearing of a new band (C-S) in its metal complexes. • The appearance of new band assigned to ν(M-O) in ChitoCin metal complexes. • The appearance of new band assigned to ν(M-O) and (M-S) in ChitoThioCin metal complexes.

24. Electronic spectra of the [Cu(ChitoCin)(NO3)(H2O)3].CH3OH Electronic spectra of the [Fe(ChitoCin)(NO3)2(H2O)3].2H2O C) Electronic spectra

25. Electronic spectra of [Co(ChitoThioCin)(NO3)(H2O)2] Electronic spectra of [Ni(ChitoThioCin)(NO3)(H2O)2] Cont. C) Electronic spectra

26. Electronic spectral data and magnetic moments of the ChitoCin and ChitoThioCin polymer ligands and their metal complexes.

27. Structures of ChitoCin complexes

28. Structures of ChitoThioCin complexes

29. [Cu(ChitoCin)(NO3)(H2O)3].MeOH [Cu(ChitoThioCin)(NO3)(H2O)2] ESR spectra of Cu-Complexes

30. TGA-DrTGA curve of [Co(ChitoCin)(NO3)(H2O)3].CH3OH Thermal degradation pattern of [Co(ChitoCin)(NO3)(H2O)3].CH3OH complex (1). TGA analysis

31. TGA-DrTGA curve of [Cr(ChitoThioCin)(NO3)2(H2O)2].21/2H2O Thermal degradation pattern of [Cr(ChitoThioCin)(NO3)2(H2O)2]. 21/2H2O complex (10). Cont. TGA analysis

32. Part II) Thermodynamic parameters Thermodynamic parameters of the metal complexes were calculated using Coats –Redfern method and standard thermodynamic equations. ln[1-(1-α)1-n /(1-n)T2] = M/T +B for n ≠ 1 ---------- (1) ln[-ln (1-α) / T2] = M/T +B for n = 1 ---------- (2) where M = -Ea/R and B = ln AR/Ф Ea ΔH = Ea – RT, ΔS = R[ln(Ah/kT)-1] and ΔG = ΔH – T ΔS (1) All decomposition stages show a best fit for (n =1) indicating a first order decomposition for the current complexes. (2) The positive values of ΔH means that the decomposition processes are endothermic. (3) The negative values of activation entropies ΔS indicate a more ordered activated complex than reactant’s and/or the reaction is slow

33. First stage Second stage Third stage Fourth stage Thermodynamiccalculations for Cu(II)ChitoCin complex 1

34. Thermadynamic parameters of ChitoCin and its complexes 1, 2, 3, 4 and 5.

35. Thermadynamic parameters of ChitoThioCin and its complexes 6, 7, 8, 9 and 10.

36. Part IV: Metal Uptake 1- Metal uptake under competitive conditions

37. Cont. Metal uptake under competitive conditions

38. Cont. Metal uptake under competitive conditions

39. 2- Metal uptake under non- competitive conditions

40. The ChitoCin and ChitoThioCin ligands were prepared from the reaction of Chitosan with cinnamoyl chloride and/or cinnamoyl isothiocyanate • ChitoCin acts as monobasic monodentate ligand which coordinates through NH-C=O site. • ChitoThioCin acts as monobasic bidentate ligand which coordinates through NH-CO-NH-C=S site. . Thermodynamic parameter of the metal complexes calculated using Coats –Redfern method and the standard thermodynamic equations. • . The two polymer ligands prefer Cu(II) ions in chelation while Ni(II) ions are the less favorable with different mixtures of metal ions. Conclusion

41. شـــــــــــكر شاكر المولى عز و جل على عظيم نعمه و جليل عطاياه و أعظمها نعمة العلم و عطية الإسلام يطيب لي أن أتوجه بخالص عبارات الشكر وأسمى آيات العرفان إلى اساتذتى الافاضل • الاستاذ الدكتور ماهر زكى السبع استاذ الكيمياء الفيزيائيه - كلية العلوم - جامعة القاهره • الدكتور/ عادل عباس عماره استاذ الكيمياء الغير العضوية المساعد –كلية التربية –جامعة عين شمس ولا يفوتني أن أتقدم بالشكر والتقديرللأستاذ الدكتور محمد محمد شكرى رئيس قسم الكيمياء وكل أساتذتي وأعضاء هيئة التدريس وجميع زملائي بقسم الكيمياء وفريق العمل بمعملأ.د. ماهر السبع لحسن تعاونهم معى