تهيه و بررسي خواص مكانيكي و ضد باكتري آميزه پلي ﴿اتيلن ترفتالات﴾ /كيتوزان

چكيده انگليسي :

100Preparation and Investigation of Mechanical and Antibacterial Properties of Poly ethylene terephthalate Chitosan Blend Masoud Tavangar m tavangar@ce iut ac ir 9 17 2011 Department of Chemical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Mahmood Masoomi m masoomi@cc iut ac irAbstractChitosan a polymer of glucosamine is industrially produced by chemical deacetylation of chitin fromshellfish The chitosan is a polycationic polymer and therefore antimicrobial activity is one of the mostimportant characteristics of this polymer Poly ethylene terephthalate PET is widely used for barriers fibers sheets packaging and films because of its excellent characteristics such as transparency andoutstanding processability It is light in weight and it has good impact resistance It is of the candidatematrice because that is inexpensive inert nontoxic and readily available The aim of this work was toevaluate the anti bacterial and mechanical properties of Chitosan based solvent cast blends with syntheticpolyester poly ethylene terephthalate The use of packaging or coating films containing antimicrobialagents could be more efficient by slow migration of the bactericidal agents from the carrier film structure tothe food surface maintaining a high concentration where it is needed For the PET Chitosan blend theamount of chitosan was varied from 1 to 9 by weight Chitosan and PET were homogeneouslydissolved in a ternary solvent system in varying mass ratios in a triflouro acetic acid chloroform and aceticacid and processed into uniform films Molecular interactions between chitosan and PET were investigatedusing Attenuated total reflectance Fourier transform infrared spectroscopy ATR FTIR Morphologies ofthese blend films were viewed using SEM Tensile strength TS and percent elongation at break E ofthe films were determined using a Universal Testing Machine Zwick1446 60 The antibacterial activity ofthe samples was evaluated utilizing the colony forming unit method against three typical human pathogenicmicroorganisms Escherichia coli Klebsiella pneumoniae and Staphylococcus aureus The results indicatedthat the PET chitosan films showed a significantly higher growth inhibition rate compared with the PETfilm control Chitosan release to solution containing acetic acid from a wide range of blends was studiedmaking use of the ninhydrin method The reaction of chitosans with ninhydrin was rapid sensitive andreproducible although non stoichiometric Since the results obtained using the ninhydrin assay would differfor different types of chitosan the work presented here involved construction of a calibration curve andevaluation of the performance of the ninhydrin assay with the particular chitosan base used in ourformulations The results indicated that the PET Chitosan blends presented significant antimicrobialactivity which increased with increasing the amount of chitosan in the films formulation asexpected Therelease tests revealed that dissolution of the biocide glucosamine groups i e the chitosan water solublefractions also increased with the amount of chitosan present in the formulation Results obtained fromATR FTIR spectra suggested that there exist pronounced interactions that probably result from hydrogenbonds between different components SEM images showed that in PET Chitosan films when the fraction ofchitosan was increased the compatibility of the two polymers seemed to also be reduced Tensile strengthand elongation at break of PET Chitosan blends decreased with the increase in chitosan content With theincrease in chitosan content from 1 to 9 per cent the tensile strength tends to decrease from 50 01 to 26 59MPa and Elongation at break decreases from 78 46 to 21 14 These results indicated that the blendsbecame brittle with the increase in chitosan content Keywords chitosan poly ethylene terephthalate antibacterial mechanical properties release

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تهيه و بررسي خواص مكانيكي و ضد باكتري آميزه پلي ﴿اتيلن ترفتالات﴾ /كيتوزان

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