A novel group of silsesquioxane derivatives, which are siloxane-silsesquioxane resins (S4SQ), was for the first time examined as possible flame retardants in polypropylene (PP) materials. Thermal stability of the PP/S4SQ composites compared to the S4SQ resins and neat PP was estimated using thermogravimetric (TG) analysis under nitrogen and in air atmosphere. The effects of the non-functionalized and n-alkyl-functionalized siloxane-silsesquioxane resins on thermostability and flame retardancy of PP materials were also evaluated by thermogravimetry-Fourier transform infrared spectrometry (TG-FTIR) and by cone calorimeter tests. The results revealed that the functionalized S4SQ resins may form a continuous ceramic layer on the material surface during its combustion, which improves both thermal stability and flame retardancy of the PP materials. This beneficial effect was observed especially when small amounts of the S4SQ fillers were applied. The performed analyses allowed us to propose a possible mechanism for the degradation of the siloxane-silsesquioxane resins, as well as to explain their possible role during the combustion of the PP/S4SQ composites.

A study was carried out involving the filling of epoxy resin (EP) with bentonites and silica modified with polyhedral oligomeric silsesquioxane (POSS). The method of homogenization and the type of filler affect the functional and canceling properties of the composites was determined. The filler content ranged from 1.5% to 4.5% by mass. The basic mechanical properties of the hybrid composites were found to improve, and, in particular, there was an increase in tensile strength by 44%, and in Charpy impact strength by 93%. The developed hybrid composites had characteristics typical of polymer nanocomposites modified by clays, with a fine plate morphology of brittle fractures observed by SEM, absence of a plate separation peak in Wide Angles X-ray Scattering (WAXS) curves, and an exfoliated structure observed by TEM.

In this article the research related to the scope increase of incremental technology in machine industry is presented. Those technologies were used for the manufacture of components from polymeric materials with torque loaded such as: shafts, clutches of gear hubs and other elements of the propulsion system in which torque is transferred. To analyze the properties of the manufactured elements the original testing stand was designed and a series of preliminary torsional strength tests of the gear shaft fittings obtained using additive techniques have been carried out. On the basis of the obtained results it was stated that there is a clear influence of the printing plane in the applied incremental technologies [SLS (selective laser sintering) and FFF (fused filament fabrication)] on the torsion resistance of the obtained elements. The properties of the shafts also depend on the type of polymeric materials which they were made of.

No abstract

No abstract

As part of the present work, polymer composites used in 3D printing technology, especially in Melted and Extruded Manufacturing (MEM) technology, were obtained. The influence of modified fillers such as alumina modified silica, quaternary ammonium bentonite, lignin/silicon dioxide hybrid filler and unmodified multiwalled carbon nanotubes on the properties of polycarbonate (PC) composites was investigated. In the first part of the work, the polymer and its composites containing 0.5–3 wt.% filler were used to obtain a filament using the proprietary technological line. The moldings for testing functional properties were obtained with the use of 3D printing and injection molding techniques. In the next part of the work, the rheological properties—mass flow rate (MFR) and mechanical properties—Rockwell hardness, Charpy impact strength and static tensile strength with Young’s modulus were examined. The structure of the obtained composites was also described and determined using scanning electron microscopy (SEM). The porosity, roughness and dimensional stability of samples obtained by 3D printing were also determined. On the other hand, the physicochemical properties were presented on the basis of the research results using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), wide angle X-ray scattering analysis (WAXS) and Fourier Transform infrared spectroscopy (FT-IR). Additionally, the electrical conductivity of the obtained composites was investigated. On the basis of the obtained results, it was found that both the amount and the type of filler significantly affected the functional properties of the composites tested in the study.

This study examined, the effect of chemically extracted raspberry pomace on the thermal stability, mechanical properties, flammability, chemical structure and processing of poly(vinyl chloride). It was observed that the pomace in this study was used to extract naphtha, thereby permitting the removal of bio-oil as a factor preventing the obtaining of homogeneous composites. Furthermore, adding 20% raspberry pomace filler after extraction extended the thermal stability time for the composites by about 30%. It was observed that composite density, impact strength, and tensile strength values decreased significantly with increasing concentrations of filler in the PVC matrix. At the same time, their modulus of elasticity and Shore hardness increased. All tested composites were characterized by a good burning resistance with a flammability rating of V0 according to the UL94 test. Adding 20 to 40% of a natural filler to the PVC matrix made it possible to obtain composites for the production of flame resistant elements that emitted less hydrogen chloride under fire conditions while ensuring good rigidity.

Badano wp³yw zawartooeci (1,0-3,0 % mas.) bentonitów modyfikowanych solami amoniowymi i fosfoniowymi na w³aoeciwooeci u¿ytkowe kompozytów na osnowie ¿ywicy epoksydowej wzmocnionych w³óknem szklanym. Oznaczono w³aoeciwooeci mechaniczne oraz odpornooeae na p³omieñ otrzymanych laminatów. Wykonano równie¿ badania za pomoc¹ skaningowej mikroskopii elektronowej (SEM) i mikroskopii si³ atomowych (AFM). Stwierdzono, ¿e laminaty z osnow¹ epoksydow¹ nape³nion¹ modyfikowanymi bentonitami charakteryzuj¹ siê znacznie wiêksz¹ odpornooeci¹ na p³omieñ i lepszymi w³aoeciwooeciami wytrzyma³ooeciowymi ni¿ laminaty wytworzone z ¿ywicy nienape³nionej.