STUDY OF THE SYNTHESIS AND CHARACTERIZATION OF A POLY (ETHYLENE SUCCINATE) BIODEGRADABLE POLYESTER WITH POSSIBLE APPLICATION AS ENCAPSULATING MATRIX OF ESSENTIAL OIL OF LEMONGRASS.
Carlos A. L. M., Diré G. F., Nascimento C. C. H. C., Nascimento S. F., Vasconcelos S.D. D. de, Camacho A. C. L. F., Oliveira J. F. F., Nogueira R. I., Barreto A. S., Pinto P. R.
ABSTRACT
In recent years, interest in biomaterials grew in the biotechnology, pharmaceutical and food industries. Within these areas, studies on natural and synthetic biopolymers for encapsulating bioactive matrices are greatly developed. To study the possibility for use as bioactive encapsulating matrix by the techniques of spray-drying and lyophilization, was obtained by the polycondensation of polyester biodegradable poly(ethylene succinate) (PES). The obtained polymer was characterized as the microstructure by Infrared Spectroscopy Fourier transform (FTIR), and thermal stability by thermogravimetric analysis (TGA) Thermogravimetric analysis and derivative (DTG), as the characteristic crystalline by optical microscopy (MO) and as to the toxicity by preliminary microbiological disk diffusion testing for bacterial strain of Staphylococcus aureus (S. aureus ATCC 8096). The FTIR profile of the curve showed an absorption around 3000 cm -1 assigned to terminal OH PES grouping. Absorptions around 1750 cm-1 and 1190 cm-1 confirmed the presence of ester carbonyl at 2450cm and vibration-1, 2200cm-1 and 2000cm-1 were assigned to be the grouping CH absorptions. The thermogravimetric curves showed a loss of 1.3% volatile at 100 °C, attributable to residual water generated as a byproduct of the reaction the PES also demonstrating its hydrophobic character. A maximum peak at 419.03°C. Degradation was also observed, and a total residual content of only 1.8% for the synthetic route employed. The micrographs obtained in optical microscopy confirmed the crystalline feature of PES obtained, as evidenced by spherulitic morphology. Preliminary in vitro microbiological tests showed no toxicity of poly(ethylene succinate) at concentrations of 12.5 mg/mL and 50mg/mL. The PES obtained was used as polymer matrix to encapsulate the essential oil of lemon grass by freeze-drying technique and the microparticles were evaluated by scanning electron microscopy (SEM). The images obtained by SEM showed particles with cluster appearance, with a well-defined and varied dimensions morphological structure, but with a tendency to form spherical structures.
Keywords: Poly(ethylene succinate); bioactive; Microencapsulation.
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