Polyethylene grafted with itaconic acid was subjected to weathering under laboratory accelerated conditions. The course of the photo-oxidative degradation process of that material was studied by FTIR spectroscopy both through quantitative measurements of changes in absorbance values at selected wave numbers and through measurements of surface area values for absorption bands which were separated by means of deconvolution. The use of both those procedures of quantitative determinations resulted in a general conclusion that the oxidation process was initiated from the very first moment of irradiation, and it produced ketones, acids, esters (intramolecular and of acetate type), peracids, peresters, hydroperoxides, and alcohols. The molecular weight values and gel number values, which were established as well, pointed out that oxidation was accompanied by cracking of polymer macromolecules, and also by polymer crosslinking to a limited degree.
Chitosan/starch-based composites were prepared by thermomechanical processing as an alternative to the traditional solution method, with the aim of fabricating environmentally friendly materials on a larger scale. Different contents and types of lignin and poly(vinyl alcohol), PVA were incorporated into chitosan/starch compositions to improve their mechanical properties. It was demonstrated that the presence of both lignin and PVA increases the values of tensile strength and elongation at break of the composites. Moreover, it was observed that by the selection of a type of lignin and PVA, it was possible to tailor the internal microstructure of the samples. As observed in scanning electron microscope (SEM) micrographs, the introduction of lignin and PVA resulted in the formation of a smooth surface and homogeneous samples.
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