Paulina Jakubowska

A novel chitosan/sponge chitin origin material as a membrane for supercapacitors – preparation and characterization

A new chitosan/sponge chitin – based membrane (CS/CH membrane) was prepared via the casting method for the first time. We used the demineralized skeleton of the marine demosponge Ianthella basta as a source for a chitinous network. The obtained membrane was immersed in 1 M LiOAc (lithium acetate) solution and tested in an Electric Double Layer Capacitor (EDLC) cell. For comparison, chitosan (CS) with LiOAc solution was also tested. The studies performed indicated good properties of the CS/CH membrane. Very good mechanical stability (for use in electrochemical capacitors) and electrochemical properties of the CS membrane were achieved by the addition of chitin isolated from the sponge to the polymer matrix. Their electrochemical performances were tested in EDLC cells by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge. The specific capacitances of the tested capacitor cells were found to be approximately 97 F g−1 and 88 F g−1 with CS/CH and CS membranes (in the voltage range 0–0.8 V), respectively.

A novel functional MgO ∙ SiO2/polyhedral oligomeric silsesquioxane hybrids as an active filler of polypropylene

Abstract New organic/inorganic hybrid fillers were obtained by mechanical modification of magnesium silicate with selected polyhedral oligomeric silsesquioxane and characterized afterwards. MgO ∙ SiO2 was precipitated in a water system. The effect of chemical modification of magnesium silicate surface on their physicochemical properties was determined. Functionalization was carried out with the use of different amount of (1-(3-hydroxypropyl)dimethylsiloxy- 3,5,7,9,11,13,15-hepta(isobutyl)pentacyclo-[9.5.1.13, 9.15, 15.17, 13]octasiloxane). The polypropylene composites of 0.5, 1.0 and 1.5 wt.% modified by 10 weight parts by the mass of the filler were also produced. For the obtained polypropylene composites measurements of the tensile strength, Young’s modulus and elongation at break were performed

Kraft lignin/cubic boron nitride hybrid materials as functional components for abrasive tools

In this study, the kraft lignin/cubic boron nitride hybrid materials have been obtained and characterized for the first time. The effectiveness of the combination of lignin and boron nitride was evaluated on the basis of Fourier transform infrared spectroscopy. Furthermore, it was confirmed that the addition of cubic boron nitride (cBN) improved the thermal stability of the inorganic-organic material. Upswing in thermal properties allowed to apply the prepared materials in preparation of model abrasive composites. Beneficial influence of the lignin/cBN filler was also proven by a noticeable decrease in the amount of harmful phenol released from the compositions during headspace gas chromatography analysis. Mechanical properties of the lignin/boron nitride hybrids and resin systems were investigated by the three-point flexural test. The obtained results show that the used additives can be promising materials for abrasive tools combining the good properties of lignin as a plasticizer and of cubic boron nitride as a filler which improves the thermal and mechanical properties of finished products and, at the same time, limits the negative impact on human health and environment.

Rheological properties of polyolefin composites highly filled with calcium carbonate

In this paper the rheological properties of highly filled polyolefin composites (HFPCs) have been investigated. Calcium carbonate (CaCO3), with stearic acid modified surface, was used as filler. Ternary compounds have been obtained by the inclusion of a CaCO3/polypropylene master batch into the high density polyethylene matrix. The highly filled polyolefin composites with CaCO3 content in the range between 40 and 64 wt% have been prepared in the molten state using a single-screw extruder, the temperature of the extrusion die was set at 230°C. The melt rheological properties of the HFPCs have been extensively investigated both in oscillatory and steady shear flow.

Thermal properties of polyolefin composites with copper silicate

The aim of this work was to specify thermal properties of polyolefin composites with copper silicate. Low density polyethylene (LDPE) and polypropylene (PP) composites with 2, 4 and 8 wt % of the filler (CuO·SiO2) were analyzed. Characteristic temperatures of the polymer compositions, i.e. the melting (Tm) and crystallization temperatures (Tc), obtained by means of Differential Scanning Calorimetry (DSC), were determined. The impact of the applied additives on composites thermal stability was established using thermogravimetry measurements (TGA). Afterwards, the flammability test was performed. The measurement was complemented with the establishment of the maximum combustion temperature using infrared recording techniques and image analysis (infrared camera). One of the most important parameter of thermoplastics is the softening point which was also determined. The measurement was carried out using a Vicat apparatus. Thermal characteristic was also supplemented with an assessment of the thermal diffusivit...

The use of thermovision technique to estimate the properties of highly filled polyolefins composites with calcium carbonate

The aim of this work was to determine the possibility of thermovision technique usage for estimating thermal properties of ternary highly filled composites (PE-MD/iPP/CaCO3) and polymer blends (PE-MD/iPP) during mechanical measurements. The ternary, polyolefin based composites that contained the following amounts of calcium carbonate: 48, 56, and 64 wt % were studied. All materials were applying under tensile cyclic loads (x1, x5, x10, x20, x50, x100, x500, x1000). Simultaneously, a fully radiometric recording, using a TESTO infrared camera, was created. After the fatigue process, all samples were subjected to static tensile test and the maximum temperature at break was also recorded. The temperature values were analyzed in a function of cyclic loads and the filler content. The changes in the Young’s modulus values were also investigated.