Danuta Matykiewicz

Physicochemical Characterization of Functional Lignin–Silica Hybrid Fillers for Potential Application in Abrasive Tools

Functional lignin–SiO2 hybrid fillers were prepared for potential application in binders for phenolic resins, and their chemical structure was characterized. The properties of these fillers and of composites obtained from them with phenolic resin were compared with those of systems with lignin or silica alone. The chemical structure of the materials was investigated by Fourier transform infrared spectroscopy (FT-IR) and carbon-13 nuclear magnetic resonance spectroscopy (13C CP MAS NMR). The thermal stability of the new functional fillers was examined by thermogravimetric analysis–mass spectrometry (TG-MS). Thermo-mechanical properties of the lignin–silica hybrids and resin systems were investigated by dynamic mechanical thermal analysis (DMTA). The DMTA results showed that abrasive composites with lignin–SiO2 fillers have better thermo-mechanical properties than systems with silica alone. Thus, fillers based on lignin might provide new, promising properties for the abrasive industry, combining the good properties of lignin as a plasticizer and of silica as a filler improving mechanical properties.

Activation of Magnesium Lignosulfonate and Kraft Lignin: Influence on the Properties of Phenolic Resin-Based Composites for Potential Applications in Abrasive Materials

Magnesium lignosulfonate and kraft lignin were activated by different oxidizing agents for use in phenolic resin composites used for the production of abrasive components. The physicochemical properties of the oxidized materials were analyzed by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), dynamic mechanical-thermal analysis (DMTA) and inverse gas chromatography (IGC). The homogeneity of the model abrasive composites containing the studied products was assessed based on observations obtained using a scanning electron microscope (SEM). FTIR and XPS analysis of the oxidized products indicated that the activation process leads mainly to the formation of carbonyl groups. The IGC technique was used to assess changes in the surface energy and the acid–base properties of the studied biopolymers. The changes in the acid–base properties suggest that more groups acting as electron donors appear on the oxidized surface of the materials. DMTA studies showed that the model composites with 5% magnesium lignosulfonate oxidized by H2O2 had the best thermomechanical properties. Based on the results it was possible to propose a hypothetical mechanism of the oxidation of the natural polymers. The use of such oxidized products may improve the thermomechanical properties of abrasive articles.

Functional lignin-SiO2 hybrids as potential fillers for phenolic binders

Abstract Functional lignin-SiO2 hybrid fillers were synthesized and characterized with a view to their potential application in binders for phenolic resins. The properties of these fillers and of composites obtained from them with phenolic resin were compared with those of systems with lignin or silica alone. The chemical structure of the materials was investigated by Fourier transform infrared spectroscopy. Surface properties of lignin-SiO2 fillers were tested using inverse gas chromatography (IGC). IGC was used for determination of surface energy and surface heterogeneity of the studied fillers. IGC made it possible to assess the adhesion between the tested fillers and phenolic resins. Interactions of functional fillers with phenolic resins were also evaluated by IGC. The results indicated that lignin-SiO2 interacted strongly with the phenolic resin, more strongly than pure lignin. This was proved by SEM observations: thanks to the stronger interactions of lignin-SiO2 hybrid with phenolic resins, a more homogeneous composite was obtained. Thermo-mechanical properties of lignin–silica and resin systems were investigated by DMTA. DMTA results showed that phenolic binders with lignin-SiO2 fillers have better thermo-mechanical properties than systems with lignin or silica alone: higher glass transition temperature and a smaller decrease in storage modulus. Lignin fillers can thus provide new, promising properties for a phenolic binder combining the good properties of lignin as a plasticizer and of silica as a filler improving mechanical properties.

Effect of heterogeneous nucleation on isotactic polypropylene-polyoxymethylene blends properties and miscibility

This paper presents a study of the effect of heterogeneous nucleation on isotactic polypropylene-polyoxymethylene (iPP-POM) blends properties and miscibility. Polyoxymethylene have been blended with polypropylene matrix in three different amounts: 25, 50, and 75 wt% with and without sorbitol based nucleating agent. Thermal and mechanical properties of blends have been investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanic thermal analysis (DMTA), static tensile test as well as rheological analysis. The structure of the blends was investigated using Scanning Electron Microscopy (SEM) and polarized optical microscopy (PM). Rheological analysis confirmed that the iPP-POM blends are partially miscible in a molten state.

Characteristics of Multifunctional, Eco-Friendly Lignin-Al2O3 Hybrid Fillers and Their Influence on the Properties of Composites for Abrasive Tools

The main aim of the present study was the preparation and comprehensive characterization of innovative additives to abrasive materials based on functional, pro-ecological lignin-alumina hybrid fillers. The behavior of lignin, alumina and lignin-Al2O3 hybrids in a resin matrix was explained on the basis of their surface and application properties determined by inverse gas chromatography, the degree of adhesion/cohesion between components, thermomechanical and rheological properties. On the basis of the presented results, a hypothetical mechanism of interactions between lignin and Al2O3 as well as between lignin-Al2O3 hybrids and phenolic resins was proposed. It was concluded that lignin compounds can provide new, promising properties for a phenolic binder combining the good properties of this biopolymer as a plasticizer and of alumina as a filler improving mechanical and thermal properties. The use of such materials may be relatively non-complicated and efficient way to improve the performance of bonded abrasive tools.

Application of waste bulk moulded composite (BMC) as a filler for isotactic polypropylene composites.

Graphical abstract

Morphology and thermomechanical properties of epoxy composites highly filled with waste bulk molding compounds (BMC)

Abstract The aim of this study was to produce epoxy composites highly filled with waste bulk molding compounds (BMC). The used amount of filler ranged from 30 wt% to 60 wt%. The influence of BMC on the epoxy resin curing process was monitored with the differential scanning calorimetry (DSC) method. Fourier transform infrared (FTIR) spectroscopy was used to evaluate the chemical structure of composites. The mechanical and thermal properties were examined by means of dynamic mechanical thermal analysis (DMTA), the Charpy method and the Shore D test. The fracture surface morphology of composites was observed with scanning electron microscopy (SEM). The storage modulus G′ of the epoxy composites with BMC was higher than the reference epoxy sample and significantly dependent on filler content. All investigated materials showed similar values of hardness, but at the same time low values of impact strength. Therefore, obtained composites can be used as low cost coating materials.

Evaluation of polypropylene hybrid composites containing glass fiber and basalt powder

Abstract Polypropylene composites filled with inorganic fillers are widely used due to their good mechanical and thermal properties. The modification efficiency of filler incorporated into thermoplastic polymer strongly depends on its shape and dimension. Therefore, the development of novel hybrid composites modified with particle and fibrous shaped fillers expands the range of thermoplastic composite applications. This work investigates the influence of glass fiber and basalt powder and their shape on the mechanical properties of polypropylene-based composites. Mechanical properties of hybrid composites were evaluated using static tensile test, impact resistance, and hardness measurements. The thermomechanical stability of the materials was evaluated via dynamic mechanical thermal analysis. Results indicated that the incorporation of inorganic fillers significantly improved the composite sample stiffness at a wide range of temperatures. The research was complemented with structure investigations realized using scanning electron microscopy. Moreover, the incorporation of basalt powder, which is well known for its low friction coefficient, improved the processing properties, as proven by the melt flow index test.

Polyethylene green composites modified with post agricultural waste filler: thermo-mechanical and damping properties

Abstract The aim of the study was to determine thermo-mechanical properties and applicability of sunflower husk waste as a filler for ultra low density polyethylene composites. The post agricultural waste filler was milled and chemically treated with (3-aminopropyl)triethoxysilane (3-APS). The amount of filler used was 5, 10 and 20 wt%. The mechanical and thermal properties of the composites containing unmodified and modified natural fillers were determined in the course of static tensile test, rebound resilience by Schob method, and dynamic mechanic thermal analysis. The influence of filler loading and chemical modification of the filler on the morphology of natural composites was evaluated by SEM analysis.

Evaluation of thermomechanical properties of epoxy–basalt fibre composites modified with zeolite and silsesquioxane

Abstract The aim of this study was to verify the influence of zeolite and silsesquioxane (POSS) addition on thermo-mechanical properties of basalt fiber reinforced epoxy composites. The dynamic mechanical thermal analysis was conducted with different frequencies at bending mode. The mechanical properties were determined at static tensile test and Charpy impact strength method. The structure of composites was determined by scanning electron microscopy. The thermal stability was characterized by thermogravimetric analyses in inert and oxidizing atmospheres. The impact strength and thermal stability of the composites with zeolite and silseqioxane were higher than the reference sample. Thus, these composites can be used as thermally stable materials with high stiffness.