Influence of organic filler on mechanical properties of polypropylene composites

Analizowano wpływ dodatku napełniacza organicznego w postaci łupin orzecha włoskiego na właściwości mechaniczne kompozytów na osnowie polipropylenu. Ponadto, porównano właściwości kompozytów z dodatkiem oraz bez dodatku kompatybilizatora w postaci bezwodnika maleinowego. Kompozyty uzyskano metodą wytłaczania przy użyciu wytłaczarki dwuślimakowej. Oznaczono cechy wytrzymałościowe w próbie statycznego rozciągania, udarność bez karbu metodą Dynstat oraz twardość metodą Shore'a D. Stwierdzono, że badane kompozyty wykazują podwyższone wartości modułu Young'a oraz twardości. Natomiast, odnotowano spadek wartości wytrzymałości na rozciąganie, wydłużenia przy zerwaniu oraz udarności.Studies on the influence of organic filler addition in a form of walnut shells on mechanical properties of polypropylene composites were presented. Furthermore, a comparison of composites' properties containing maleic anhydride as well as without its presence was introduced. The composites were prepared by extrusion using a twin-screw extruder. In order to determine mechanical properties of the composites the following tests were conducted: static tensile test, Shore D hardness and Dynstat impact test. It was found that the composites have higher values of Young's modulus and hardness in comparison to neat polypropylene. On the other hand, a decrease in tensile strength, elongation at break and impact strength was noted

Influence of heterogeneous nucleation on thermodynamic properties of isotactic polypropylene

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

Wpływ rodzaju plastyfikatora na właściwości odnawialnych materiałów inżynierskich

Polymers and their composites are commonly used as engineering materials. They reveal a number of beneficial properties that allow their use in many industries. However, the main disadvantage of polymeric materials is their long degradation time in environment. For this reason, there is a need to replace synthetic polymers with renewable ones which are of plant or animal origin. Potato starch-based polymer was produced and characterized in this study. An influence of plasticizers on rheological, thermal and morphological properties of the plasticized starch was studied herein.Polimery i ich kompozyty to powszechnie stosowane materiały inżynierskie. Mają one szereg korzystnych właściwości, które umożliwiają stosowanie ich w wielu gałęziach przemysłu. Podstawową wadą materiałów polimerowych jest ich długi czas degradacji w środowisku naturalnym. Z tego powodu dąży sie do zastępowania polimerów syntetycznych odnawialnymi polimerami pochodzenia roślinnego lub zwierzęcego. W pracy wytworzono i scharakteryzowany polimer na bazie skrobi ziemniaczanej. Oceniono wpływ plastyfikatora na wybrane właściwości reologiczne, cieplne i morfologiczne materiału polimerowego

Composition-property relationship of polyurethane networks based on polycaprolactone diol

This work was focused on the synthesis of polyurethane networks (PUNs) based on polycaprolactone (PCL) as soft segment (SS) and Boltorn (R) aliphatic hyperbranched polyester of the second pseudo generation and 4,4 '-diphenylmethane diisocyanate (MDI) as the parts of the hard segments (HS), by a two-step solution polymerization. In order to find the best ratio between HS and SS to achieve good thermal and mechanical properties, suitable hydrophobicity and morphology of the PUNs, various experimental analyses were conducted. The obtained results revealed that features of the PUNs highly depend on the PCL content. The increase in the PCL content leads to the increase in thermal stability, hydrophobicity and appearance of the microphase separation, but on the other side, it also leads to the decrease in storage modulus in the rubbery plateau, crosslinking density and glass transition temperatures of PUNs. This work shows that features of PUNs can be easily adjusted for a specific application by careful selection of the SS and HS ratio

Poly(l-Lactic Acid)/Pine Wood Bio-Based Composites

Bio-based composites made of poly(l-lactic acid) (PLLA) and pine wood were prepared by melt extrusion. The composites were compatibilized by impregnation of wood with γ-aminopropyltriethoxysilane (APE). Comparison with non-compatibilized formulation revealed that APE is an efficient compatibilizer for PLLA/wood composites. Pine wood particles dispersed within PLLA act as nucleating agents able to start the growth of PLLA crystals, resulting in a faster crystallization rate and increased crystal fraction. Moreover, the composites have a slightly lower thermal stability compared to PLLA, proportional to filler content, due to the lower thermal stability of wood. Molecular dynamics was investigated using the solid-state 1H NMR technique, which revealed restrictions in the mobility of polymer chains upon the addition of wood, as well as enhanced interfacial adhesion between the filler and matrix in the composites compatibilized with APE. The enhanced interfacial adhesion in silane-treated composites was also proved by scanning electron microscopy and resulted in slightly improved deformability and impact resistance of the composites

Thermal and Thermo-Mechanical Properties of Poly(L-lactic Acid) Biocomposites Containing β-Cyclodextrin/d-Limonene Inclusion Complex

Bio-based composites made of poly(L-lactic acid) (PLLA) and β-cyclodextrin/d-limonene inclusion complex (CD-Lim) were prepared by melt extrusion. Encapsulation of volatile d-limonene molecules within β-cyclodextrin cages was proven to be a successful strategy to prevent evaporation during high-temperature processing. However, small amounts of limonene were released upon processing, resulting in the plasticization of the polymeric matrix. Morphological analysis revealed good dispersion of the filler, which acted as a nucleating agent, favoring the growth of PLLA crystals. The composites′ lowered glass transition temperature upon the addition of CD-Lim was also proved by thermomechanical analysis (DMA). Moreover, DMA revealed constant stiffness of modified materials at room temperature, which is crucial in PLLA-based formulations

Thermal and Morphological Analysis of Linear Low-Density Polyethylene Composites Containing d-limonene/β-cyclodextrin for Active Food Packaging

Composites made of linear low-density polyethylene (LLDPE) and β-cyclodextrin/d-limonene inclusion complex (CD-lim) were prepared by melt extrusion to develop a novel food packaging material. Scanning electron microscopy evidenced a fairly good dispersion of the filler within the polymeric matrix. Infrared spectroscopy coupled with thermogravimetric analysis confirmed the presence of CD-lim in the composites, proving that the applied technology of including the essential oil within β-CD cages allows for preventing a sizable loss of d-limonene despite a high temperature and shear applied upon extrusion processing. Moreover, the influence of the filler on the thermal properties of PE was assessed. It was found that the cyclodextrin-based inclusion complex significantly fastens the crystallization path of the polyethylene matrix with an improved crystallization rate of the PE/CD-lim composites compared to the neat polymer

Thermal and Morphological Analysis of Linear Low-Density Polyethylene Composites Containing <span style="font-variant: small-caps">d</span>-limonene/β-cyclodextrin for Active Food Packaging

Composites made of linear low-density polyethylene (LLDPE) and β-cyclodextrin/d-limonene inclusion complex (CD-lim) were prepared by melt extrusion to develop a novel food packaging material. Scanning electron microscopy evidenced a fairly good dispersion of the filler within the polymeric matrix. Infrared spectroscopy coupled with thermogravimetric analysis confirmed the presence of CD-lim in the composites, proving that the applied technology of including the essential oil within β-CD cages allows for preventing a sizable loss of d-limonene despite a high temperature and shear applied upon extrusion processing. Moreover, the influence of the filler on the thermal properties of PE was assessed. It was found that the cyclodextrin-based inclusion complex significantly fastens the crystallization path of the polyethylene matrix with an improved crystallization rate of the PE/CD-lim composites compared to the neat polymer