Characterization of Chitosan-Based Active films with and without the addition of nanoparticles

JAVIER LAMARRA; SANDRA RIVERO; ADRIANA PINOTTI

Buenos Aires

Workshop; BIPOLI 2015; 2015

INTRODUCTIONChitosan (CH) is among the most used biodegradable materials. This polymer has amine groups highly reactants in its structure, which allow modifying its functionality by means of the incorporation of active compounds as the gallic acid (GA). This component can be added directly or can be nanoencapsulated before incorporating them in a polymeric matrix [1]. In the present work, physicochemical, mechanical and microstructural properties of active matrices of CH with or without nanoparticles included in them were studied. MATERIALS AND METHODSChitosan solution of 1.5% (w/w) was prepared by solubilization in 1.5% (v/v) acetic acid solution under stirring for 24 h. Films were formulated by means of the addition of 50 mg/g Q of GA (CHGA) and other matrices containing active nanoparticles (CHNP) were obtained by the method of ionotropic gelification [2]. CH films were used as control.Moisture content was measured at 105ºC. The optical properties (opacity, transparency) and UV barrier were analyzed by using a spectrophotometer (Beckman DU 650). Film solubility and swelling were evaluated under different pH conditions (2, 4.1 and 7.4). Water vapor permeability (WPV) was determined according to the procedure described by Mali et al. [3]. Likewise, the mechanical properties of the materials were studied throughout tension assays in a texturometer (TA.XT2i ? Stable Micro Systems (Surrey, England) equipped with a tension grip system A/TG. Microstructural analysis was carried out by scanning electron microscopy (SEM, FEI m Quanta 200) and Fourier transform infrared (FTIR, Nicolet, iS10 Thermo Scientific).RESULTS AND DISCUSSIONThe incorporation of nanoparticles in the polymeric matrices resulted in a significant reduction (p < 0.05) in the solubility of the material, this trend being more marked with the increase of the pH. The values of swelling showed a similar behavior because of the decrease in the amount of reactive amine groups with the increase of pH lead to a minor water solubility value. Not only the incorporation of nanoparticles (CHNP) but also the addition of GA resulted in a decrease in WVP value of 27 and 58 %, respectively.All active developed films resulted be UV barrier. Also, an increase in opacity and a decrease in transparency were observed. Materials with higher elongation were obtained because of the inclusion of nanoparticles in the matrices (15, 4 and 19, 1 for CH and CHNP, respectively)FTIR spectra showed a shift of the peak from 3290 to 3275 cm-1, indicating a movement reduction of the N-H due to the interaction with the TPP. Cross-section micrograph of CHNP highlights the inclusion of nanoparticles in the CH matrix