Enzymatic degradation of biostatic materials based on polylactide

The paper presents the research results for enzymatic degradation of biodegradable materials in proteinase K. Polylactide and its composites containing a biostatic substance in the form of sulphanilic acid salt PHMG were tested as part of the research project. Three different concentrations of the biostatic substance were used: 0.2%, 0.6% and 1.0 % of the mass. The research results of differential scanning calorimetry (DSC) for the tested materials were compared both before and after the enzymatic degradation. Photographs obtained from a scanning electron microscope (SEM) and the analysis of the foil physical mass loss confirmed that these materials were susceptible to enzymes

Growth of selected fungi on biodegradable films

This study presents the data summary on growth speed of selected species of fungi on some of biodegradable polymer materials. Growth speed was assessed on films composed of poly(lactide), poly(ε-caprolactone) and poly(hydroxybutyrate) after a month of incubation in 24oC. To assess growth of fungi optical microscopy on densitometric measurements were used. Through these analyses the best growth was confirmed for fungus: Chaetomium globosum (ATTC 6205) on a film made of poly(ε -caprolactone)

EMULSION POLYMERIZATION OF THIOPHENE – THE NEW WAY OF CONDUCTING POLYMERS SYNTHESIS

The aim of this study was to investigate the new method of polythiophene polymerization. It was made an attempt of the chemical oxidation of thiophene in aqueous medium without the addition of any surfactant. The oxidative compound applied in the synthesis was gaseous ozone. Resulting polymer was obtained in the form of nano-spheres dispersed in water. The method developed in this study allow to obtain the polythiophene nanoparticles. Further study is required to fully identify the resulting product properties in comparison with polymer obtained in other methods

Biological Effects and Toxicity of Compounds Based on Cured Epoxy Resins

The aim of this work was to investigate selected biological and toxicity properties of cured epoxy resin-based compounds based on a bisphenol A epoxy resin, cold-cured by a polyamide and containing two types of metal powders (aluminum and copper). This study involved cytotoxicity analysis, pH measurements, absorbance measurements and sterilization. The cytotoxicity analysis was conducted to determine the harmful degree of the cured epoxy resin. Aimed at identifying toxic agents in cured compounds, the cytotoxicity analysis involved absorbance measurements in an entire wavelength range. Cytotoxicity and absorbance results demonstrated that the extracts of all the tested resin samples had no cytotoxic effects on the cells of living organisms. The absorbance values obtained over the entire wavelength range did not point to the formation of aggregations, which proved that no toxic agents harmful to living organisms were extracted from the resin samples. Based on the results obtained, it can be concluded that all tested compounds, based on epoxy resins, which are also used as adhesives in various applications, are essentially safe materials when using such formulations in a cured state

Antibacterial films based on PVA and PVA-chitosan modified with poly(hexamethylene guanidine)

In this study, thin, polymeric films consisting of poly(vinyl alcohol) (PVA) and chitosan (Ch) with the addition of poly(hexamethylene guanidine) (PHMG) were successfully prepared. The obtained materials were analyzed to determine their physicochemical and biocidal properties. In order to confirm the structure of PHMG, nuclear magnetic resonance spectroscopy (H-1 NMR) was applied, while in the case of the obtained films, attenuated total reflectance infrared spectroscopy with Fourier transform (FTIR-ATR) was used. The surface morphology of the polymer films was evaluated based on atomic force microscopy. Furthermore, the mechanical properties, color changes, and thermal stability of the obtained materials were determined. Microbiological tests were performed to evaluate the biocidal properties of the new materials with and without the addition of PHMG. These analyses confirmed the biocidal potential of films modified by PHMG and allowed for comparisons of their physicochemical properties with the properties of native films. In summary, films consisting of PVA and PHMG displayed higher antimicrobial potentials against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria in comparison to PVA:Ch-based films with the addition of PHMG.Nicolaus Copernicus University in Torun, Poland (Faculty of Chemistry) [2019/1023]; Ministry of Education, Youth and Sports of the Czech RepublicMinistry of Education, Youth & Sports - Czech Republic [LO1504

Polylactide-Based Films Incorporated with Berberine—Physicochemical and Antibacterial Properties

A series of new polymeric materials consisting of polylactide (PLA), polyethylene glycol (PEG) and berberine chloride (B) was evaluated. PEG was incorporated into the polymer matrix with the aim of obtaining a plasticizing effect, while berberine was added in order to obtain antibacterial properties in formed packaging materials. Materials were formed using the solvent-casting procedure. Fourier transform infrared spectroscopy and scanning electron microscopy were used so as to establish the structural changes resulting from the introduction of berberine. Thermogravimetry and differential scanning calorimetry were applied to study the thermal properties. Further, mechanical properties and differences in colour and transparency between the control sample and films containing berberine were also studied. The recorded data indicates that berberine formed a network on the surface of the PLA-based materials. Introduction of an active compound significantly improved thermal stability and greatly affected the Young’s modulus values of the studied polymeric films. Moreover, it should be stressed that the addition of the studied active compound leads to an improvement of the antibacterial properties, resulting in a significant decrease in growth of E. coli and the S. aureus bacteria cultures

Structural and Thermal Properties of Nanocomposites Based on Polyolefins and Montmorillonite Modified with Ethyl 2-Aminobenzoate

Our efforts were focused on improving thermal stability of polyethylene (PE) and polypropylene (PP) through incorporation of new organically modified montmorillonite. The reactive organofilic montmorillonite (MMT-EA) was prepared by exchanging the interlayer inorganic cations in montmorillonite by a large excess of ethyl 2-aminobenzoate (EA). Organic modification can affect not only microstructures, but also the properties of the polymer - montmorillonite nanocomposites. In the next step novel polyolefins/ organoclay nanocomposites were prepared by melt intercalation process. In order to obtain this new family of materials and enhance their properties was used very low filler level, from 1.5 to 5 wt.%. The dispersion of the montmorillonite layers in the polymers was characterized by using X-ray diffraction (XRD). The thermal properties and structure changes were studied by different scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Further studies indicated that the exfoliated clay modified with EA improved thermal stability of the PE and PP/MMT-EA nanocomposites