(715e) Synthesis and Characterization of Novel Stimuli-Responsive Hydrogels Based on Polyglycerol

The present study was focused on the synthesis and characterization of a hydrogel material from glycerol. The synthesized hydrogel absorbs up more than 7 times its own weight. The hydrogel absorption capacity changes in response to temperature and pH external stimuli. A hydrogel is a high-valued added product of glycerol, a co-product of the transesterification of vegetable oils. This work is part of the effort to  develop new technologies for using glycerol as a building block for valuable chemicals that may contribute to transform the actual biodiesel industry into a bio-refinery [1]. The studied hydrogel was synthetized using as building block polyglycerol obtained by the direct polymerization of glycerol. Polyglycerol has been used as starting material for drug delivery [2, 3] temperature-responsive copolymers [4], dyes adsorption from aqueous media [5], among many other applications [6-9]. Recently, Salehpour and coworkers have been reported the synthesis of polyglycerol – based hydrogels using poly (ethylene glycol) diglycidyl ether (PEGDE) as crosslinking agent [10]. In this work, polyglycerol was cross-linked with biodegradable acids such as citric and oleic acids. Chemical reactions involved in the functionalization of polyglycerol were esterification and acid-catalyzed hydration of alkenes. The effect of the proportion of cross-linked agents, citric, and oleic acid, in the final physical properties of the hydrogel were studied. It was found that hydrogel properties depend on the content of cross-linked agent, the ratio between citric and oleic acid, the functional groups present in these acids as well as their molecular length. The characterized hydrogel has heterogeneous porous with diameters in a range of 5-50. The relation between the synthetized hydrogel glass transition temperature and its response to external stimuli is discussed. Physical and chemical properties were analyzed by Scanning Electron Microscopy (SEM), Differential Scanning Calorimetric (DSC), Thermogravimetric Analysis (TGA), and Fourier Transform Infrared Spectroscopy (FTIR).  

REFERENCES

1.            Yuguo Zheng, X.C., and Yinchu Shen, Commodity chemicals derived from glycerol, an important biorefinery feedstock. Chemical  Reviews, 2010. 108: p. 5253–5277.

2.            Steinhilber, D., et al., Surfactant free preparation of biodegradable dendritic polyglycerol nanogels by inverse nanoprecipitation for encapsulation and release of pharmaceutical biomacromolecules.J Control Release, 2012.

3.            Calderon, M., et al., Development of efficient acid cleavable multifunctional prodrugs derived from dendritic polyglycerol with a poly(ethylene glycol) shell. J Control Release, 2011. 151(3): p. 295-301.

4.            Taylor, D.K., et al., Temperature-Responsive Biocompatible Copolymers Incorporating Hyperbranched Polyglycerols for Adjustable Functionality. J Funct Biomater, 2011. 2(3): p. 173-194.

5.            Chen, Z., et al., Multicarboxylic hyperbranched polyglycerol modified SBA-15 for the adsorption of cationic dyes and copper ions from aqueous media. Applied Surface Science, 2012. 258(13): p. 5291-5298.

6.            Li, M., et al., Methotrexate-conjugated and hyperbranched polyglycerol-grafted Fe(3)O(4) magnetic nanoparticles for targeted anticancer effects. Eur J Pharm Sci, 2013. 48(1-2): p. 111-20.

7.            Ahn, C.H., J.-D. Jeon, and S.-Y. Kwak, Photoelectrochemical effects of hyperbranched polyglycerol in gel electrolytes on the performance of dye-sensitized solar cells. Journal of Industrial and Engineering Chemistry, 2012. 18(6): p. 2184-2190.

8.            Mamiński, M.Ł., et al., Fast-curing polyurethane adhesives derived from environmentally friendly hyperbranched polyglycerols – The effect of macromonomer structure. Biomass and Bioenergy, 2011. 35(10): p. 4461-4468.

9.            Mamiński, M.ł., M. Czarzasta, and P. Parzuchowski, Wood adhesives derived from hyperbranched polyglycerol cross-linked with hexamethoxymethyl melamines. International Journal of Adhesion and Adhesives, 2011. 31(7): p. 704-707.

10.         Salehpour, S., C.J. Zuliani, and M.A. Dubé, Synthesis of novel stimuli-responsive polyglycerol-based hydrogels. European Journal of Lipid Science and Technology, 2012. 114(1): p. 92-99.