ABSTRACT Crosslinking is one of the most commonly reactions used to improve the physical properties of cellulose derivatives. Cellulose Acetate Propionate (CAP) is a commercial ester obtained as a cellulose derivative and it can be used as basis for the synthesis of crosslinked chains as described in this work. Typical used crosslinkers are di-functional compounds, such as dianhydrides or diisocyanate. The formation of polymeric 3D structures as described in this work occurs typically by the reaction of the linear chains bearing free OH groups with crosslinking agents such as dianhydrides. These reactions are used to make a very absorbent material, typically a gel. The syntheses were performed in homogeneous medium with acetate propionate in a very dry atmosphere by employing PMDA (Pyromellitic Dianhydride) and BTDA (3,3’, 4,4’ Benzophenone Tetracarboxylated Dianhydride) as crosslinking agents in a reflux system. TGA analysis has shown the different thermal stability of the gels when compared with CAP. Typical TGA curves have demonstrated the lower stability of the crosslinked chains when compared to CAP as consequence of esther linkages formed in the gels structures. The Mc, which is the value for the molar mass between crosslinkings points in 3D structure, was determined according to Flory-Rehner theory. This important parameter has demonstrated greater reactivity of PMDA in comparison with the BTDA in the reactions conditions’ employed in this work.
Cite this paper
P. Dantas and V. Botaro, "Synthesis and Characterization of a New Cellulose Acetate-Propionate Gel: Crosslinking Density Determination," Open Journal of Polymer Chemistry, Vol. 2 No. 4, 2012, pp. 144-151. doi: 10.4236/ojpchem.2012.24019.
 M. Phiriyawirut and P. Maniaw, “Cellulose Microfibril from Banana Peels as a Nanoreinforcing Fillers for Zein Films,” Open Journal of Polymer Chemistry, Vol. 2, 2012, pp. 56-62. doi:10.4236/ojpchem.2012.22007
 Y. Zhang, P. C. Zhu and D. Edgren, “Crosslinking Reaction of Poly(vinyl alcohol) with Glyoxal,” Journal of Polymer Research, Vol. 17, No. 5, 2010, pp. 725-730.
 S. Baljit, G. S. Chauan, S. Kumar and N. Chauan, “Synthesis, Characterization and Swelling Responses of pH Sensitive Psyllium and Polyacrylamide Based Hydrogels for the Use in Drug Delivery (I),” Carbohydrate Polymers, Vol. 67, No. 2, 2007, pp. 190-200.
 V. R. Botaro, L. Caux and K. M. Novack, “Evaluation of Physical Properties of Bleached Eucalyptus Fibers after Thermal Treatment,” Research & Review in Polymers, Vol. 3, 2012, pp. 32-39
 C. S. R. Freire, A. J. D. Silvestre, C. P. Neto, R. M. A. Rocha, “An Efficient Method for Determination of the Degree of Substitution of Cellulose Esters of Long Chain Aliphatic Acids,” Cellulose, Vol. 12, No. 5, 2005, pp. 449458. doi:10.1007/s10570-005-2203-2
 V. R. Botaro, V. Alvarenga and V. A. Le?o, “Swelling Kinetics of Hydrogels of Cellulose,” Polymeric Materials: Science & Engineering, Vol. 23, 2010, pp. 455 – 456.
 V. Oliveira, “Síntese e Caracteriza??o de Géis de Acetato de celulose Reticulados Com Dianidrido Piromelítico e Dianidrido Do ácido 3,3’,4,4’ Benzofenona Tetracarboxílico,” Disserta??o de Mestrado, Programa de Pós-Gradua??o em Engenharia de Materiais, REDEMAT, Ouro Preto, 2008.
 R. F. T. Stepto, “Polymer Networks Principles of Their Formation Structure and Properties,” London, 1998
 P. K. Chatterjef and B. S. Gupta, “Absorbent Technology,” Textile Science and Technology, Elsevier, 2002
 F. L. Buchholz and N. A. Peppas, “Superabsorbent Polymers, Science and Technology,” ACS Symposium Series No. 573, American Chemical Society, Washington DC, 1994. doi:10.1021/bk-1994-0573
 C. Peniche, M. A. Cohen. B. Vazquez and J. S. Román, “Water Sorption of Flexible Networks Based on 2-Hydroxyethyl Methacrilate-Triethylenglycol Dimethacrylate Copolymers,” Polymer, Vol. 38, No. 24, 1997, pp. 5977-5982. doi:10.1016/S0032-3861(96)01058-0
 N. Peppas, A. Nikolaos and A. R. Khare, “Preparation, Structure and Diffusional Behavior of Hydrogels in Controlled Release,” Advanced Drug Delivery Reviews, Vol. 11, No. 1-2, 1993, pp. 1-35.
 E. M. Santos, M. Aguiar, M. A. F. César-Oliveira, S. F Zawadzki and L. Akcelrud, “Determina??o do Parametro de Solubilidade de Poliuretanos de PBLH,” Polimeros: Ciência e Tecnologia, Vol. 10, No. 2, 2000, pp. 64-69.
 V. R. Botaro and V. Alvarenga, “Hidrogéis Superabsorventesa Base de Acetato de Celulose Modificado por Dianidrido BTDA,” Polímeros: Cência e Tecnologia, Vol. 19, 2009, pp. 278-284.