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In order to investigate the effect of rotaxane formation on the photophysical and morphological properties of π‐conjugated materials, a new main chain polyrotaxane was synthesized through Suzuki coupling between the inclusion complex of 5,5'‐dibromo‐2,2'‐bithiophene with randomly methylated β‐cyclodextrin and 9,9‐dioctylfluorene‐2,7‐trimethylene diborate. Due to rotaxane formation, a blue shift in the absorption spectra as well as in the fluorescence spectra was observed, while the fluorescence quantum yields and fluorescence lifetimes remained unchanged. This study demonstrates that rotaxane formation can alter the electronic and morphological properties of the threaded copolymer, which is of great interest for electronic applications. magnified image

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The biodegradation of poly(vinyl alcohol) and poly(vinyl alcohol)‐graft‐lactic acid copolymers was analyzed, using Trichotecium roseum fungus. The samples were examined during biodegradation at different periods of exposure. Structural modifications of the biodegraded samples were investigated by Fourier transform infrared‐attenuated total reflectance spectroscopy, and the surface morphology was investigated by scanning electron microscopy. The static light scattering results concluded that the weight average molecular mass (Mw) of the copolymers increased after biodegradation, because the fractions with low molecular weight of the copolymers were destroyed. The thermal behavior and stability of the samples before and after the biodegradation period were investigated by differential scanning calorimetry (DSC) and thermogravimetric analyses. The thermogravimetric analyses and their derivatives (TG‐DTG) showed that the thermal stability of the biodegraded samples was more raised comparatively to the unbiodegraded ones. The DSC results demonstrated that biodegradation took place in the amorphous domains of the investigated polymer samples and the crystallinity degree increased after 24 biodegradation days. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41777.