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Poly(3-hydroxybutyrate) is a biopolymer which is used to production of implants in the human body. On the other hand, the physical and mechanical properties of poly(3-hydroxybutyrate) are compared to the properties of isotactic polypropylene what makes poly(3-hydroxybutyrate) possible substitute for polypropylene. Unfortunately, the melting point of poly(3-hydroxybutyrate) is almost equal to its degradation temperature what gives very narrow window of its processing conditions. Therefore, numerous attempts are being made to improve the poly(3-hydroxybutyrate) properties. In the present work, hybrid nanobiocomposites based on poly(3-hydroxybutyrate) as a matrix with the use of organic nanoclay - Cloisite 30B and linear polyurethane as a second filler have been manufactured. The linear polyurethane was based on diphenylmethane 4,4'-diisocyanate and diol with imidazoquinazoline rings. The obtained nanobiocomposites were characterized by X-ray diffraction, scanning and transmission electron microscopies, thermogravimetry, differential scanning calorimetry and their selected mechanical properties were tested. The resulting hybrid nanobiocomposites have intercalated/exfoliated structure. The nanobiocomposites characterize a higher thermal stability and a wider range of processing temperatures compared to the unfilled matrix. The plasticizing influence of nanofillers was also observed. In addition, the mechanical properties of the discussed nanobiocomposites were examined and compared with those ones of the unfilled poly(3-hydroxybutyrate). The new-obtained nanobiocomposites based on poly(3-hydroxybutyrate) containing 1% Cloisite 30B and 5% by mass of the linear of polyurethane characterized the highest improvement of processing conditions. They have the biggest difference between the temperature of degradation and the onset melting temperature, about 100°C. [ABSTRACT FROM AUTHOR]

Medical-grade polyvinyl chloride was modified by incorporation of silver nitrate in a concentration range from 0 to 5 wt.% using a solvent casting technique. Agar diffusion test was performed to evaluate in-vitro antimicrobial properties of prepared samples. The obtained systems were characterized by tensile test, X-ray photoelectron spectroscopy, scanning electron microscopy, and optical microscopy. The micrographs revealed a better morphological disposition of silver particles along the polyvinyl chloride matrix in the samples cast fromN,N-dimethylformamide. Nevertheless, the applied modification did not appreciably influence the tensile properties of the prepared systems compared to the reference samples. [ABSTRACT FROM AUTHOR]

The main goal of this work is to correlate morphological parameters of the binary blend of polyamide 6 (PA6) and a polylactide (PLA) based biodegradable co-polyester blend (BioFlex) (scanning electron microscopy, solvent extraction method) with the solid-state mechanical properties (stress strain analysis) as well as thermal (differential scanning calorimetry) and selected physico-chemical characteristics (Fourier transform infrared spectroscopy and water uptake analysis). The blends of PA6/BioFlex were prepared in ratios of 100/0, 90/10, 75/25, 60/40, 50/50, 40/60, 25/75, 10/90 and 0/100 in wt.%. The occurrence of co-continuous morphology was observed within the range of 40 to 60 wt.% of BioFlex. Furthermore, the results show that the co-continuous morphology of PA6/BioFlex blends significantly affected both tensile (E modulus) and thermal properties (melting enthalpy) of the blends. In the case of the tensile properties, the effect of the morphological arrangement was strongly dependent on the deformation range. The presence of BioFlex in the blends reduced the crystallizability of PA6 noticeably. Co-continuous structure formation was observed to have a significant effect on the melting enthalpy of the blend. Composition morphology dependent responses were observed in the case of the FTIR and water uptake studies. [ABSTRACT FROM PUBLISHER]

This work is dedicated to compatibilization process investigation between polyamide 6 and biodegradable polylactide. The process was conducted by newly developed polyalkenyl-poly-maleic-anhydride-imide/amide agents over a selected range of composition to identify morphologies and properties of these blends. The properties of resulted blends were studied by scanning electron microscopy, solvent extraction techniques, mechanical testing, Fourier transform infrared spectroscopy, and differential scanning calorimetry measurements. Results show that blending of the two polymers without compatibilizers produced multiphase blends. It was shown by scanning electron microscopy imaging that addition of prepared compatibilizers reduced a domain size of a dispersed phase and also changes in nearly co-continuous state occurred. Static and dynamic mechanical properties were improved, and especially impact strength and tensile strength were the most sensitive on the presence of compatibilizers. [ABSTRACT FROM PUBLISHER]

Fully and partially hydrolyzed poly(vinyl alcohol) (PVA) was modified with zinc sulphate in the concentration range from 0 to 9 wt% of recalculated zinc content using the solvent cast technique. The resulting polymeric films were characterized by optical microscopy, stress–strain analysis, differential scanning calorimetry and Fourier transform infrared spectroscopy (FT-IR–ATR). In addition, agar diffusion test and dilution and spread plate technique were used for determination of antibacterial properties of the films against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae) bacterial strains. A mathematical model was applied on the measured data and parameters characterizing the antibacterial efficiency of the material were calculated and discussed. The results revealed that the PVA hydrolysis degree can play an important role in all studied properties, including antibacterial activity of the all PVA-based materials. [ABSTRACT FROM AUTHOR]

Abstract: There has been a growing interest in developing antibacterial polymeric materials. The logical consequence following development of a new material is optimisation of its processing conditions and investigation of the influence of processing parameters on functionality of a given material. The present work deals with investigation of the effect of preparation temperature on the mechanical and antibacterial properties of polymer films based on poly(vinyl alcohol) (PVA) and silver nitrate (0, 1, 3, 5, 7, 9 wt.% silver content). The mechanical properties of the films prepared at various temperatures (25, 35, 50, 60, 75 °C) were characterized by using stress–strain analysis. Antibacterial properties were determined by using an agar diffusion test and a dilution and spread plate technique against both Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae). The results show significant effect of the elevated temperature on the samples properties. [Copyright &y& Elsevier]

Poly(vinyl alcohol) (PVA) was modified by zinc nitrate in the concentration range from 0 to 22.29 wt.% using the solvent cast technique. The resulting material was characterized by optical microscopy, stress-strain analysis, differential scanning calorimetry, UV-visible spectroscopy, and Fourier transform-infrared spectroscopy. In addition, the antibacterial properties of the prepared films were tested against the both gram positive and gram negative bacterial strains. The results show the uniform distribution of the modifier within the PVA matrix, enhanced mechanical properties (up to 8.24 wt.%), and good antibacterial activity against gram negative bacteria at low modifier content. [ABSTRACT FROM AUTHOR]