سنتز و شناسايي پلي هيدرازيدهاي آروماتيك غير مسطح مشتق شده از باز تروگر

چكيده انگليسي :

Non coplanar Rigid rod Aromatic Polyhydrazides Containing Tr ger s Base Mansooreh Kheradmandfard m kheradmandfard@yahoo com March 15 2011 Department of Chemistry Isfahan University of Technology Isfahan 84156 83111 I R Iran Degree M Sc Language FarsiDr A Abdolmaleki Email abdolmaleki@cc iut ac ir amirabdolmaleki@yahoo comAbstract Polyhydrazide materials are of great interest because they enhance dyeability of synthetic fibers improveelasticity over other polymer types and their use in reverse osmosis separations The polyhydrazides are highperformance materials that have ability to spin to high modulus fibers and could be used as a reinforcedplastics and tire cords In particular they are soluble polymers with potential to convert to other highlythermally stable polymers like polyoxadizoles and polytriazoles Aromatic polyhydrazides that are classifiedunder a category of heat resistance materials are usually made by reacting diacyl chloride with dihydrazideat low temperature solution condensation or Yamazaki s phosphorylation method using dihydrazide anddicarboxylic acid Tr ger s base is a rigid V shaped compound that is chiral by virtue of the two stereogenicnitrogen atoms in the diazocine bridge It was the first chiral tertiary amine to be successfully resolved as it isunable to undergo pyramidal inversion Compounds based on this framework are of interest because of theirpotential to function as artificial receptors and catalysts in asymmetric transformations Tr ger s baseanalogues are produced as racemic mixtures from an acid catalysed condensation of anilines andformaldehyde and much of the chemistry of these systems has focussed on increasing the type offunctionality on the aniline units The rigid V shaped Tr ger s base unit suppress coplanar structures lowerregularity and molecular ordering Also the Tr ger s base that is unable to undergo pyramidal inversion isinteresting because of their potential to function as artificial receptors There are some reports in the literatureon different applications of polymers containing Tr ger s base which have conformationally andgeometrically well defined linker Since this unit has good ability to prevent the close packing of chains anddecreases interchain interaction it has been suggested that synthetic polymers containing Tr ger s unit canbe dissolved by organic solvents Thus the presence of the V shaped Tr ger s unit in the finalmacromolecules was thought to lead to obtain amorphous polyhydrazides which have high solubility inorganic solvents low softening temperatures good thermal and mechanical properties and easy meltprocessability A new aromatic dihydrazide containing Tr ger s base 2 8 bis carboxylic 6H 12H 5 11 methanodibenzo b f 1 5 diazocine dihydrazide was prepared by the condensation of ethyl p aminobenzoate with hexamethylenetetramine in the presence of trifluoroacetic acid followed by convertingto the dihydrazide with a high yield and high purity A series of new aromatic polyhydrazides were preparedfrom dihydrazide containing V shaped Tr ger s base and various aromatic diacyl chlorides via low temperature solution polycondensation in quantitative yields Among several different reaction pathways thathave been developed for polyhydrazide synthesis low temperature polycondensation by the reaction ofdiacyl chloride with dihydrazide is the most popular method All of the polyhydrazides were amorphous andreadily soluble at room temperature in polar organic solvents such as N N dimethylacetamide and N methyl 2 pyrrolidone These polymers could be solution cast into transparent tough and flexible films with goodmechanical properties They had useful levels of thermal stability associated with good glass transitiontemperatures 163 172 C 10 weight loss temperatures in excess of 460 C and char yields at 800 C innitrogen higher than 39 Keyword Poly hydrazides High performance polymers Tr ger s base Amorphous Heteroatom containing polymers Poly 1 3 4 oxadiazoles

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سنتز و شناسايي پلي هيدرازيدهاي آروماتيك غير مسطح مشتق شده از باز تروگر

پليمرهاي پايدار حرارتي , آمورف , پليمرهاي حاوي هترواتم , پلي﴿4،3و1-اكساديازول ها﴾