تهيه و بررسي خواص نانو كامپوزيت هاي پلي ﴿آميد-ايميد﴾/ اكسيد روي فعال نوري جديد و پلي وينيل الكل/ خاك رس اصلاح شده / اكسيد روي مشتق شده از آمينو اسيدهاي L- فنيل آلانين و L- تيروسين

چكيده انگليسي :

Preparation and Properties of Novel Optically Active Poly amide imide ZnO and Poly vinyl alcohol Modified Cloisite Na ZnO Nanocomposites Derived from L Phenylalanine and L Tyrosine Amino acids Maryam Madani m madani65@yahoo com 9 February 2011 Department of Chemistry Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor Prof Shadpour Mallakpour E mail mallak@cc iut ac ir mallak777@yahoo com mallakpour84@alumni ufl edu Abstract In this investigation a series of novel chiral and biodegradable polymer nanocomposites zinc oxid ZnO based on amino acid were synthesized For this purpose at first poly amide imide PAI was prepared viasolution polycondensation of N N pyromellitoyl bis phenylalanine diacid chloride with 4 4 diaminodiphenylsulfone Optimized conditions in term of reaction time and temperature were also studied The optically active PAI was obtained with good yield and the structure of polymers was confirmed bydifferent characterization methods such as fourier transform infrared spectroscopy FT IR 1H NMR andelemental analysis The thermogravimetric analysis TGA termograms of the resulting polymer showedgood thermal stability In the second project for compatibility with polymer matrix the hydrophilic ZnOnanoparticles were treated with coupling agent of methacryloxypropyltrimethoxy silane KH570 and aminopropyltriethoxysilane KH550 Then PAI ZnO nanocomposites were synthesized under ultrasonicirradiation conditions The resulting nanocomposites were characterized by various techniques including FT IR X ray diffraction XRD and their morphology were investigated by scanning electron microscope SEM field emission scanning electron microscopy FE SEM and transmission electron microscopy TEM The FE SEM and TEM results indicated that the ZnO nanoparticles were dispersed homogenously inpolymer matrix In modified ZnO the organic chains of coupling agent can fulfill steric hindrance betweeninorganic nanoparticles and prevent their aggregation The modified nanoparticles might be dispersedabsolutely and will combine with PAI via the H bonding of C O or NH groups of coupling agent with NH C O and SO2 groups in PAI The unmodified OH groups on the surface of ZnO nanoparticle can bondto the amide group C O of PAI through interchain hydrogen bonding The thermal properties ofnanocomposites were studied by TGA The TGA confirmed that the heat stability of the nanocomposites withincreased nanoparticles content was improved In the other project Cloisite Na was modified via cationexchange reaction using natural L tyrosine amino acid This novel chiral organomodified Cloisite Na wascharacterized using FT IR XRD and TGA Then the poly vinyl alcohol PVA nanocomposite was preparedby dispersing organomodified Cloisite Na in PVA via ultrasonic irradiation The results showed that amixture of intercalated and exfoliated Cloisite Na dispersion in PVA matrix The TGA data was comparedwith the pure PVA and the results showed that the introduction of a small amount of Cloisite Na Tyr led toimprovement in thermal stability of the obtained new nanocomposites UV visible transmission spectra ofpure PVA and new nanocomposites film in the visible light region 400 800 nm showed that they are rathertransparent For the last project nanocomposites of PVA Cloisite Na ZnO with different of ZnO contentwere prepared The resulting nanocomposites were characterized by various techniques including FT IR XRD and their morphology were investigated by SEM FE SEM and TEM The FE SEM and TEM resultsindicated that the nanoparticles were dispersed homogenously in polymer matrix The thermal properties ofnanocomposites were studied by TGA TGA confirmed that the heat stability of the nanocomposites wasimproved The optical properties of nanocomposites were investigated by UV vis technique Due to existenceof amino acid in the backbone of obtained PAI and ZnO in nanocomposites it is predictable to bebiodegradable Keyword Optically active polymers Nanocompo

مدني، مريم

ZnO , معرف هاي اصلاح كننده , پايداري حرارتي , زيست تخريب پذيري