ABSTRACT The reaction of chitosan with cinnamic acid gave the corresponding N-cinnamoyl chitosan (NCC) polymer. The chem-ical structure of the modified polymer was characterized by IR, 1H-NMR and elemental analysis. Thermogravim- etric analysis reveals that the thermal stability of chitosan polymer is greater than NCC polymer. The activation energies of thermal degradation of chitosan and NCC polymers were determined using Arrhenius relationship. Thermal degradation of NCC polymer was studied and the products of degradation were identified by GC-MS technique. It seems that the mechanism of degradation of NCC polymer is characterized by elimination of low-molecular weight radicals. Combination of these radicals and random scission mechanism along the backbone chain are the main source of the degradation products.
Cite this paper
M. Diab, A. El-Sonbati, M. Al-Halawany and D. Bader, "Thermal Stability and Degradation of Chitosan Modified by Cinnamic Acid," Open Journal of Polymer Chemistry, Vol. 2 No. 1, 2012, pp. 14-20. doi: 10.4236/ojpchem.2012.21003.
 W. Sajomsang, P. Gonil and S. Saesoo, “Synthesis and Anti-bacterial Activity of Methylated N-(4-N,N-Di-methylaminocinnamyl) Chitosan Chloride,” Eu-ropean Polymer Journal, Vol. 45, No. 8, 2009, 2319-2328.
 V. V. Binsu, R. K. Nagarate, V. K. Shahi and P. K-Glosh, “Studies on N-Methylene Phosphonic Chitosan/Poly(Vinyl Alcohol) Com-posite Proton-Exchange Membrane,” Reactive and Functional Polymers, Vol. 66, No. 12, 2006, pp. 1619-1629. doi:10.1016/j.reactfunctpolym.2006.06.003
 D. Britto and O. B. G. Assis, “A Novel Method for Obtaining a Quaternary Salt of Chitosan,” Carbohydrate Polymers, Vol. 69, No. 2, 2006, pp. 305-310.
 H. K. V. Pashanth and R. N. Tharanathan, “Chitin/Chitosan: Modifications and Their Unlimited Application Potential an Overview,” Trends in Food Science Technology, Vol. 18, No. 3, 2007, pp. 117-131.
 F. A. A. Tirkistani, “Thermal Analysis of Some Chitosan Schiff Bases,” Polymer Degradation and Stability, Vol. 60, No. 1, 1998, pp. 67-70.
 M. M. Thanou, J. C. Verhoef, S. G. Romeijn, J. F. Nagelkerke, K. Merkus and H. E. Junginger, “Effects of N-Trimethyl Chitosan Chloride, A Novel Absorption Enhancer, on Caco-2 Intestinal Epithelia and the Ciliary Beat Frequency of Chicken Embryo Trachea,” Interna-tional Journal of Pharmaceutics, Vol. 185, No. 1, 1998, pp. 73-82. doi:10.1016/S0378-5173(99)00126-X
 T. Kean, S. Roth and M. Thanou, “Trimethylated Chitosans as Non-Viral Gene Delivery Vectors: Cytotoxicity and Transfection Effi-ciency,” Journal of Controlled Release, Vol. 103, No. 3, 2005, pp. 643-653.
 S. Cafaggi, E. Russo, R. Stefani, R. Leadi, G. Cavigliodi and B. Paradi, “Preparation and Evaluation of Nanoparticles Made of Chitosan or N-Trimethyl Chitosan and a Cisplatin-Alginate Complex,” Journal of Con-trolled Release, Vol. 121, No. 1-2, 2007, pp. 110-123.
 C. Fu, Z. Zhi-Rong, Y. Fang, Q. Xuan, W. Minting and H. Yuan, “In Vitro and in Vivo Study of N-Timethyl Chitosan Nanoparticles for Oral Protein Delivery,” International Journal of Pharmaceutics, Vol. 349, No. 1-2, 2008, pp. 226-233. doi:10.1016/j.ijpharm.2007.07.035
 G. Crini, “Recent Developments in Polysaccharide-Based Materials Used as Ad-sorbents in Wastewater Treatment,” Journal of Polymer Science, Vol. 30, No. 1, 2005, pp. 38-70.
 E. Agullo, M. S. Rodtiquez, V. Ramos and L. Albertengo, “Present and Future Role of Chitin and Chitosan in Food,” Macromolecular Bios-cience, Vol. 3, No. 10, 2003, pp. 521-530. doi:10.1002/mabi.200300010
 A. Chenite, C. Chaput, D. Wang, C. Cambes, M. D. Buschmann, C. D. Hoemann, J. C. Leroux, B. L. Atkinson, F. Binette and A. Selmani, “Novel Injectable Neutral Solutions of Chitosan form Biodegradable Gels in Situ,” Biomaterials, Vol. 21, No. 21, 2000, pp. 2155-2161.
 S. H. Hsu, S. W. Whu, C. L. Tsai, Y. H. Wu, H. W. Chem and K.H. Hsieh, “Chitosan as Scaffold Materials: Effects of Molecular Weight and Degree of Deacetylation,” Journal of Polymer Research, Vol. 11, No. 2, 2004, pp. 141-147. doi:10.1023/B:JPOL.0000031080.70010.0b
 H. Sashiwa and S. I. Aiba, “Chemically Modified Chitin and Chitosan as Biomaterials,” Progress in Polymer Science, Vol. 29, No. 9, 2004, pp. 887-908.
 M. Huang, E. Khora and L. Y. Lim, “Uptake and Cytotoxicity of Chitosan Molecules and Nanoparticles: Effects of Molecular Weight and Degree of Deacetylation,” Pharmaceutical Research, Vol. 29, No. 2, 2004, pp. 344-353.
 M. Bi-hair-varga, C. Spulchre and E. Moczar, “Thermoanalytical Studies on Protein-Polysaccharide Complexes of Connective Tissue,” Journal of Thermal Analysis and Calorimetry, Vol. l7, No. 2, 1975, pp. 675-683
 F. A. A. Tirkistani, “Thermal Analysis of Some Chitosan Schiff Bases,” Polymer Degradation and Stability, Vol. 60, No. 1, 1988, pp. 67-70.
 M. A. Diab, A. Z. El-Sonbati and D. M. D. Bader, “Thermal Stability and Degra-dation of Chitosan Modified by Benzophenone,” Spectrochimica Acta Part A, Vol. 79, No. 5, 2011, pp. 1057-1062. doi:10.1016/j.saa.2011.04.019
 M. A. Diab, A. Z. El-Sonbati, D. M. D. Bader and M. Sh. Zoromba, “Thermal Stability and Degradation of Chitosan Modified by Acetophe-none,” Journal of Polymers and the Environment.
 E. Fe-randez-Megia, R. Novaa-Carbollal, E. Quinoa and R. Riguera, “Optimal Routine Conditions for the Determination of the De-gree of Acetylation of Chitosan by 1HNMR,” Carbohydrate Polymers, Vol. 61, No. 2, 2005, pp 155-161. doi:10.1016/j.carbpol.2005.04.006
 M. Lavertu, Z. Xia, A. N. Serreqi, M. Berrada, A. Rodrigues, D. Wang, M. D. Busch-mann and A. A. Gupta, “A Validated 1H NMR Method for the Determination of the Degree of Deacetylation of Chitosan,” Journal of Pharmaceutical and Biomedical Analysis, Vol. 32, No. 6, 2003, pp. 1149-1158. doi:10.1016/S0731-7085(03)00155-9
 R. Rinaudo, M. Milas and P. L. Dung Inern, “Characterization of Chitosan. Influence of Ionic Strength and Degree of Acetylation on Chain Expansion,” International Journal of Biological Macromolecules, Vol. 15, No. 5, 1993, pp. 281-285. doi:10.1016/0141-8130(93)90027-J
 R. A. A. Muzzarelli, A. Ferrero and M. Pizzoli, “LightScattering, X-Ray Differaction, Elemental Analysis and Infrared Spectroscopy Characterization of Chitosan, a Chelating Polymer,” Talanta, Vol. 19, No. 10, 1972, pp. 1222-1226. doi:10.1016/0141-8130(93)90027-J