Mateusz Barczewski

Thermal Stability and Flammability of Polypropylene-Silsesquioxane Nanocomposites

This article presents a study of the thermal stability of polypropylene-based nanocomposites filled with tetrasilanolphenyl silsesquioxane (phPOSS). Nanofillers were introduced into a polypropylene matrix in three different amounts: 2, 5, and 10 wt.%. Investigations were carried out by means of thermogravimetric analyses conducted in inert and oxidizing atmospheres, Fourier transform-infrared spectroscopy, scanning electron microscopy, and flammability UL-94 test. The addition of phPOSS into the polymeric matrix increased thermal stability in comparison to neat iPP and introduced significant changes in the flammability of iPP/phPOSS nanocomposites.

Synthesis and Influence of Sodium Benzoate Silsesquioxane Based Nucleating Agent on Thermal and Mechanical Properties of Isotactic Polypropylene

Novel sodium benzoate modified silsesquioxane (nbPOSS) for isotactic polypropylene modification was synthesized and characterized. The influence of the novel silsesqioxane based nucleating agent on mechanical and thermal properties of commercial isotactic polypropylene was observed and compared with sodium benzoate. The mechanical investigations revealed changes in polymeric structure indicating that nucleating process had occurred. Synthetic route of 1-(3-benzoyloxypropyl)-3,5,7,9,11,13,15-hepta(isobutyl)pentacyclo-[9.5.1.13,9.15,15.17,13]octasiloxane and its characterization were presented.

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.

Development and Characterization of the Injection-Molded Polymer Composites Made from Bicomponent Fibers

The results of this study are related to the implementation of the concept of self-reinforced composites. The input materials in preparation process were the bicomponent fibers. The studies were carried out on three types of fibers, HDPE/PP, cPP/PP, LPET/PET. In each case, the matrix material was a low melting polymer, and the core was made of a higher melting point polymer. The research was conducted for the materials shaped by an injection-molding technique. The analyses confirmed the two-component structure. Properties of the resulting composites confirmed the applicability of bicomponent fibers in the preparation of self-reinforced composites. GRAPHICAL ABSTRACT

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.

Influence of heterogeneous nucleation on thermodynamic properties of isotactic polypropylene

Abstract In this paper we have investigated the effect of 1,2,3-trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]-nonitol sorbitol used in varying amounts (0.01 - 1 wt %) on isotactic polypropylene (iPP) matrix. We have used dynamic mechanical thermal analysis (DMTA) and differential scanning calorimetry (DSC) to study glass transition temperatures and crystallinity as a function of the nucleating agent concentration. Isotactic polypropylene samples showed a strong dependency on amount of α nucleating agent used. An increasing content of sorbitol based nucleating agent led to an increase of crystallization temperature upon cooling from the melt at constant rate and a decrease of the glass transition temperatures.

Dynamic pressure analysis as a tool for determination of sharkskin instability by extrusion of molten polymers

Abstract Increasing requirements which extruded polymeric products should accomplish are imposed to quantitatively characterize the factors which have a considerable effect on extrusion stability. Investigation has been realized by means of a rheological measurement device including a single screw extruder, as well as a rheological die, signal acquisition and analysis system. Due to a specially designed measurement track and modern signal processing technique, the separation of cyclic instabilities from received signals (representing the course of melt pressure) and the definition of the influence on the extrusion process were feasible. This paper demonstrates an example of the application of two new methods which facilitate the detection of sharkskin instability, irrespective of visual observation of the extrudate. Autocorrelation function and frequency analysis based on a fast Fourier transformation (FFT) were used as numeric tools applied to register and control the extrusion process. The flow of molten polymer was studied under various processing conditions, giving an opportunity to split high frequency pressure fluctuations by means of the autocorrelation function and fast Fourier transform, and to create, in the future, a catalogue of data which can be used to define particular distortions in technological investigations.

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.