Polyamidoimide

Thermo-oxidative Degradation of Polyesterimides, Polyamidoimides, Aliphatic-Aromatic Polyamides [7, 21, 40-43]... 

Various workers have discussed aspects other than those mentioned above in studies of the viscoelastic properties of polymers. These include PVOH [62], hydroxy-terminated polybutadiene [63], styrene-butadiene and neoprene-type blends [64], and polyamidoimides [65]. Other aspects of viscoelasticity that have been studied include relaxation phenomena in PP [66] and methylmethacrylate-N-methyl glutarimide copolymers [67], shear flow of high-density polyethylene [68], Tg of PMMA and its copolymers with N-substituted maleimide [69] and ethylene-vinyl acetate copolymers [70], and creep behaviour of poly(p-phenylene terephthalate) [71] and PE [72]. 

The influence of NO2 on the mechanical properties of polyamidoimide films has been considered at 323 K and F(N02) = 13 kPa [23]. The temperature dependences of the storage modulus E and loss modulus E" have been obtained for various times of NO2 exposure. A nonmonotonic decrease of E was observed at 473 K, but the maximum of the E temperature dependence appears at approximately the same temperature. Samples exposed to NO2 for eight days show an increase in E at the glass transition temperature (563 K). The phenomenon is assoeiated with chain breakage and the recombination of macroradicals giving rise to crosslinking. Chain breakage is supported by results obtained by the present authors. The ESR spectra of polyamidoimide exposed to an NO2 atmosphere show the formation of iminoxyl radicals with spectral parameters that are close to those of PVP iminoxyl radicals. The possible mechanism of their formation includes the main-chain decomposition step as follows ... 

L.I. Subbotina, A.A. Bakanova, E.R. Kofanov, E.N. Popova, E.N. Vlasova, V.M. Svetlichnyi, optically active polyamidoimides based on amino acids containing cyclohexane fragment. Rus. J. Appl. Chem. 88, 1661-1666 (2015)... 

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