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The transformation of the micro-domain structure of polyimide films during thermally induced chemical conversion from the polyamic acid prepared from 3,3‘,4,4‘-diphenyl tetracarboxylic dianhydride and p-phenylene diamine, also in the presence of triphenyl phosphate, is studied with a transmission electron microscope. The surface morphology of the films is typified by a broad size distribution of micro-domains that depends on the history of the sample treatment. To describe these observations thermodynamics of irreversible processes is used with the special feature that very slowly running stationary nonequilibrium states are considered to operate as temporary states of reference. In terms of an increment model a generalized version of the law of mass action comes out that holds under stationary nonequilibrium conditions. The observed stationary nonequilibrium patterns developed at elevated temperatures under different conditions (also in the presence of a stabilizer) are different due to process controlled temporarily fixed constraints. However, they belong altogether to the same universal class. The crucial point is that these domain ensembles are optimized controlled by the same logistics. One of the central symmetries demanded by the model is thus impressively exemplified this way, demonstrating the quality of the concept. The tenacity of the films is also studied. The results interpreted in terms of the kinetic conception of fracture of solids are shown to depend in a defined manner on the domain structure of the polymers.

The mechanical properties of films prepared from mixed acetic acid aqueous solutions of chitosan (Mw = 400,000; Mw/Mn = 3.8) and poly(ethylene oxide) (PEO) (viscosity average molecular weight of 200,000 or 600,000) were determined. A chitosan:PEO weight ratio of 10:2 improved the mechanical properties compared with pure chitosan films. The improvement of the mechanical properties correlated with a small reduction of the correlation length measured by small‐angle neutron scattering (SANS).

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Molecular dynamics of a low-band gap polymer, poly­{[4,8-bis­[(2-ethylhexyl)­oxy]­benzo­[1,2-b:4,5-b′]­dithiophene-2,6-diyl]­[3-fluoro-2-[(2-ethylhexyl)­carbonyl]­thieno­[3,4-b]­thiophenediyl]} (PTB7), and its 1:1.5 wt blend with a fullerene derivative, [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM), accessible for organic photovoltaics was studied with the broadband dielectric spectroscopy (BDS) technique in a wide range of frequency (from 10–1 to 106 Hz) and temperature (from −130 to 150 °C). In the BDS spectra, three types of molecular mobility of the polymer chains designated as γ-, β1-, and β2-relaxations, along with conductivity and electrode polarization processes, were recognized, separated, and analyzed. The relaxation processes in PTB7 and PTB7:PC71BM were described with Arrhenius-type equations and related parameters were found. Their analysis allowed us to reveal the influence of the PC71BM molecules on the dynamics of the polymer chains. Based on dc conductivity data, the Cole–Cole diagrams for PTB7 and PTB7:PC71BM were plotted. They allowed for estimating the hole lifetime and its comparison with the hole extraction time.