Abstract
X-ray structural analysis and infrared spectroscopy were the basis of investigation of the crystalline structure of two oriented polyester imides (PEI-II and PEI-III) prepared by chemical and thermal imidization of poly(acid)amido esters (PAAE) based on paraphenylene-bis-trimellitatedianhydride and aromatic diamines, namely the 4,4′-diaminodiphenyl and bis-4-aminophenyl esters of hydroquinone. It is shown that, as a result of stretching (150–250% extensions) and further heat treatment (370–390°), highly oriented crystalline structures appear in the samples. the space cell of PEI-II is monoclinic ( a = 5·56; b=7·94; c=58 A ̊ ; γ=86° ). The parameters of the rhombic cell proposed for PEI-III are: a=5·64; b=8·05; c=34·5 A ̊ . The dichroism of the absorption bands in the IR polarized spectra of PEI-II and PEI-III provided a basis for calculating the direction of the transition moments of a number of vibrations relative to the molecular axis. The conformational structure of the macromolecules is proposed for the polyester imides in the light of experimental results.
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