Agnieszka Gutowska

Molecular and Supramolecular Changes in Polybutylene Succinate (PBS) and Polybutylene Succinate Adipate (PBSA) Copolymer during Degradation in Various Environmental Conditions

In this paper, the influence of the various degradation conditions, on the molecular and supramolecular structure of polybutylene succinate (PBS) and polybutylene succinate adipate (PBSA) copolymer during degradation is described. The experiment was carried out by the use of injection molded samples and normalized conditions of biodegradation in soil, composting and artificial weathering. Materials were studied by size-exclusion chromatography (SEC) coupled with multiangle laser light scattering (MALLS) detection and wide-angle X-ray diffraction (WAXD). Additionally, the physical and mechanical properties of the samples were determined. The performed experiments clearly show difference impacts of the selected degradation conditions on the macroscopic, supramolecular and molecular parameters of the studied aliphatic polyesters. The structural changes in PBS and PBSA explain the observed changes in the physical and mechanical properties of the obtained injection molded samples.

Chemical Modification of Starch-Protein Material Performed in Order to Obtain a Half Product for Thermoplastic Processing

This article presents the results of tests which were carried out on a starch-protein biomaterial produced from wheat. The research was performed in order to assess optimal conditions for performing the chemical modification (acetylation and oxidation reactions) and its influence on the physico-chemical properties of the new biomaterial. Modifying agents were acetic acid anhydride with the presence of NaOH and K2CO3 activators as well as hydrogen peroxide, whose effects were catalysed with Cu2+ ions. Modified polymers with a degrees of substitution from 0.38 to 2.45 and oxidation from 1.0 to 35% were obtained in the process. The polymers obtained were characterized with various levels of starch degradation, minimal when the acetylation reaction activated with the K2CO3 method was used, moderate to high when the acetylation reaction was activated by NaOH, and maximal starch degradation was observed when oxidation was catalysed with Cu2+ ions. The modified polymers showed minor thermal granulation abilities and did not achieve thermoplastic abilities. Evaluation of the modification effects was carried out with absorption spectroscopy in infra-red radiation with the Fourier transformation (FTIR) technique, DSC, scanning electron microscopy and determining the boundary viscosity value.

Utilization of Cereal and Milling Industry Products as Raw Materials for the Manufacture of Biopolymer Technical Products

The pressure which is being exerted on manufacturers by the users of consumer goods towards more environmentally friendly applications, favours the use of already existing environmentally friendly raw materials or the search for new ones. One of the promising directions for research is aimed at developing new packaging materials based on biopolymers. Research recently conducted made it possible to use hydrothermally pre-treated starch/ protein raw material in the manufacture of a new generation of biopolymer materials. Biopolymer products obtained by various modifications were used to produce an exemplary batches of mouldings and packaging materials (films, corrugated cardboard).

Chitosan-Modified Cellulosic Nonwoven for Application in Gynecology. Impact of the Modification Upon Chemical Purity, Structure and Antibacterial Properties

Physical-chemical, morphological and physical-mechanical characterization was made for cellulose nonwoven modified with chitosan nanoparticles with a view to their possible use in medicine as gynecological tampons. It was an aim of the work to assess the impact of the addition of chitosan nanoparticles upon the biological activity and toxicity of the materials prepared. Methodology was prepared for the examination of the gynecological devices in the range of their useful properties, notably the mechanical strength, surface density and absorption. Aqueous extracts were examined after an extraction process that simulated standard use of the medical device, and after a surplus extraction. The content of water-soluble-, surfactantand reductive substances was estimated as well as the contents of heavy metals like cadmium, lead, zinc and mercury by the ASA method. Morphology examination permitted to assess the impact of the extraction processes on the fibre structure. Antibacterial activity against Escherichia coli and Staphylococcus aureus, and antifungal activity against Candida albicans was measured. Altogether examinations were made to assess whether the cellulosic nonwoven modified with chitosan nanoparticles meets the demands of medical devices and lends itself to the manufacture of tampons.

Heat Plasticization of Functional Wheat Flour by Extrusion in the Presence of Plasticizers

Innovative functional flours with the trade name Q-Farin were used in the preparation of biopolymer materials with properties adequate to the production of biodegradable multifunctional packaging. To meet the assumed goal, it was necessary for the modification and functionalization of starch-protein material derived from the milling of purified wheat grain to confer hydrophobic, thermoplastic and barrier properties upon it. Unmodified and modified functional flour with the tradename Q-Farin C1000 was plasticized by pressurethermal treatment in a mixture with typical plasticizers: glycerol, sorbitol & ethylene glycol. The modification of starch was accomplished by its esterification with acetic acid, enzymatic esterification with oleic acid or by oxidation with hydrogen peroxide. Mechanical and viscoelastic properties of the granulated thermoplastic compositions were examined. Their structure (microscopic and SEM observation), thermoplastic and processing properties as well as their susceptibility to biodegradation and phytotoxicity were also assessed. Selected thermoplastic compositions with adequate properties were processed into film and shapes. The materials obtained were examined for their physical properties like grammage and strength. Parameters of the technology processes involved were also prepared.

Investigation on the Structure and Properties of Modified Products from the Grain-Mill Industry for Use in the Preparation of Biopolymer Technical Materials

In the new century, the possible use of raw materials, half-products and materials derived from renewable resources is attracting growing attention. Green technologies come into play to exploit natural raw materials, including biopolymers such as cellulose, lignin chitin and chitosan, and starch. The company Lubella Sp. z o. o. S.K. (Lublin, Poland) is a manufacturer of innovative flour products of the Q-Farin series, which find use as starting materials in the preparation of new biodegradable and multifunctional biomaterials for packaging materials and paper processing. The preparation of innovative technology concepts opens ways toward the competitiveness and development of companies operating in the advanced sector of biodegradable packaging with the use of territorial renewable raw materials.

Chemical Purity of Biodegradable Medical- Grade Fibres of Aliphatic Copolyesters

Fibres prepared on an experimental scale from biodegradable copolyester of glycolide and lactide (PLGA) and from PLGA with the addition of 9% of atactic poly([R,S]-3-hydroxybutyrate (PLGA+a-PHB) were characterised to assess their possible use in the preparation of surgery sutures. Commercial spinfinish Estesol PF 790 (Bozzetto Group, Italy) was applied on the fibres in the spinning step. A method was prepared for an organic extraction of the spinfinish from the PLGA fibres, and the process efficacy was assessed by scanning electron microscopy (SEM) and by estimating chemical purity. With spinfinish removed, the fibres were subjected to an extraction process which simulated the utilisation of the products in an aqueous medium. The aqueous extracts were analysed to estimate contamination contents. Also estimated was the time in which the fibres degrade when subjected to surplus extrac tion in an aqueous medium.