تهيه و بررسي خواص پلي استيرن حاوي نانو ذرات اكسيد فلزي توسط حلال سبز ليمونن

چكيده انگليسي :

Study and Preparation of Polystyrene Containing Metal Oxide Nanoparticles Using Limonene as a Green Solvent Maryam Kheirandish m kheirandish@tx iut ac ir Date of Submission 2011 10 19 Department of Textile Engineering Isfahan University of Technology Isfahan84156 83111 Iran Degree M Sc Language Persian Supervisor Sedighe Borhani sborhani@cc iut ac ir Advisor Shadpour Mallakpour mallak@cc iut ac irAbstractRecently the introduction of inorganic nanoparticles NPs which show unique physical and chemicalproperties to organic polymers have attracted much attention and have been applied in various fields Organic inorganic nanocomposites NCs offer an effective way to improve the physical properties of theconventional polymers Solvents such as DMF THF and DMAc are good and well known for polystyrene PS These solvents emit unpleasant smell or toxic vapor and cause environmental problems and difficulty ofprocess handling Limonene is natural oil extracted from citrus fruits and is used as cleaner pesticide andsolvent Limonene the principal component of orange peel oil has been identified as a non toxic agent withpotential for cancer chemotherapy It is a major constituent of oil of citrus rind dill oil and oil of cumin bergamot and caraway In this work we used zinc oxide ZnO and titanium dioxide TiO2 as metal oxideNPs and described the fabrication of metal oxide PS NCs Natural solvent d limonene is used for producingPS NCs PS NCs thin films produced by casting homogeneous solution of metal oxide NPs and PS Also NPsfibers of PS were prepared by electrospinning of homogeneous solution of metal oxide NPs and PS First theproperties of electrospun PS fibers which were produced from PS dissolved in the limonene and DMF werecompared It was observed that the diameter of PS fiber from PS limonene is larger than PS DMF due to thelower electrical conductivity of the solvent PS NCs containing NPs were prepared by PS limonene solutionscontaining dispersed NPs of TiO2 or ZnO FE SEM images of NCs revealed well dispersion of ZnO NPs inthe PS NCs and some aggregation of TiO2 NPs in these NCs Results showed that the PS fiber diameter wasdecreased with increasing in ZnO or TiO2 NPs content Thin layer of metal oxide NCs significantly increasedthe UV blocking UV protection properties of NCs increased with increased metal oxide content of NCs UV shielding efficiency of NCs containing 8wt of ZnO or TiO2 NPs is over 99 of UV light at wavelengthsbetween 280 and 400 nm Optical transparency in the visible region of PS TiO2 NCs was slightly lower thanthat of PS ZnO NCs due to aggregation of TiO2 NPs X ray diffraction pattern of nanopcomposite fibers andfilms confirmed the presence of NPs in the samples FTIR spectra of NCs obviously showed thecharacteristic absorption peaks related to only polymeric groups This showed that there is no chemicallinkage or interaction between PS and metal oxide NPs in the resulting composites Since the amount of NPsin the sample is negligible with respect to polymer no peak from NPs in NCs spectrum was observed Evaluating the effect of metal oxide NPs amount on mechanical properties of electrospun layer showed thatthe tensile strength and elasticity modulus of the electrospun layer of PS were increased by addition of ZnONPs Up to 4wt content of TiO2 the tensile strength and elasticity modulus of electrospun layer wereincreased and with higher amount of NPs the tensile strength and elasticity of electrospun layer weredecreased due to aggregation of NPs Mechanical properties of PS films were increased by increasing themetal oxide NPs content TGA results showed that thermal stability of the NCs increased due to increasing ofZnO NPs in PS electrospun fibers and films Considering of differential scanning calorimeter DSC thermograms for electrospun PS fibers indicated that introduction of metal oxide NPs decreased the glasstransition temperature Tg This decrease of the Tg might be due to plasticizer role of NPs The Tg of PS filmincreased by

خيرانديش، مريم

تهيه و بررسي خواص پلي استيرن حاوي نانو ذرات اكسيد فلزي توسط حلال سبز ليمونن

اكسيد روي , دي اكسيد تيتانيوم , نانو كامپوزيت , الكترو ريسي