Papers by Keyword: Polyamide 66

Abstract: Polyamide 66 (PA 66) or Nylon 66 is a strong, easily processed polymer with high thermal resistance and excellent mechanical properties. Tungsten carbide (WC/Co-Cr 86/10-4), known for its exceptional hardness and elasticity, is commonly used for coatings in the thermal spraying and coating industry. In this study, we examined the microstructural, mechanical, and thermal properties of composites made from waste micro and nano WC/Co-Cr 86/10-4 powder and a PA66 matrix. PA66 was reinforced with varying ratios of 3, 6, and 10 wt.% WC/Co-Cr 86/10-4. The composite specimens were created by mechanically mixing granular PA66 and micro and nano WC/Co-Cr 86/10-4 powders and molding them under controlled temperature. Mechanical properties were evaluated through ductility and hardness tests, while thermal properties were determined through DSC analysis. The SEM observation revealed the distribution of WC/Co-Cr 86/10-4 within the polymer matrix. The DSC analysis indicated that the composite had a slightly higher melting temperature than pure PA66, and the thermal conductivity also increased slightly. The experimental results demonstrated that the mechanical properties of the composite improved as the WC/Co-Cr 86/10-4 content increased, specifically in terms of tensile strength and hardness. Additionally, the composite exhibited enhanced interfacial adhesion, mechanical behavior, and thermal properties. This composite, utilizing WC/Co-Cr 86/10-4 waste and recycled PA66, allows for the repurposing of industrial waste.

Abstract: Polyamide 66 (PA66) benefits from excellent mechanical properties and good chemical resistance, which enabled wide application of this material in various industrial fields; however, it suffers from high flammability. Generally, preparation of a flame retardant PA from a reactive flame retardant involves a two-step process. In this study, the flame retardant PA66s (FRPA66s) are synthesized via a one-pot melt copolycondensation route by using a reactive phosphorus-containing flame retardant (FR-B). Then, molecular weight, some mechanical and thermal properties along with flame retardant properties of FRPA66s were investigated by gel permeation chromatography (GPC), instron material testing, differential scanning calorimetry (DSC), thermogravimetry (TG) analysis, vertical burning test (UL 94), and limiting oxygen index test (LOI) techniques. The experimental results confirmed that FRPA66s synthesized by the one-pot method have very similar properties compared to those obtained via the two-step process. Moreover, the prepared materials showed good non-flammability behavior with limiting oxygen index value of over 30% and a vertical burning test result of V-0 rating.

Abstract: In the present study, glass fiber reinforced Polyamide 66 composites were produced using laboratory type twin screw extrusion and injection molding processes. The glass fiber reinforcement was applied at 1, 10, 15, 20, 25 and 30 wt% loadings. The morphological structure of the samples and failure modes of glass fiber reinforced Polyamide 66 composites were investigated using scanning electron microscopy (SEM) analysis on fractured surfaces of tensile tested samples in this study.

Abstract: Glass wool is discontinuous glass fiber with the average diameters of 3-4 μm produced by means of centrifugal process, and mainly applied to heat and acoustic insulation. But, there are few reports on glass wool applied to reinforcement of plastic materials in which chopped strand made by chopping continuous glass fiber is used primarily. In this study, the polyamide 66-based composite material samples containing glass wool were prepared and its wear property as a mechanical property was evaluated. It was found that the composite has an advantage on the wear property compared with a conventional glass fiber reinforced plastic, and the result suggests that glass wool has a possibility as a reinforcement material applied to plastic parts required wear resistance.

Abstract: The presented article deals with the research of micro-mechanical properties in the surface layer of modified Polyamide 66 filled by 30% of glass fibers. These micro-mechanical properties were measured by the Depth Sensing Indentation - DSI method on samples which were non-irradiated and irradiated by different doses of the β - radiation. Radiation doses used were 0, 15, 30 and 45 kGy for filled Polyamide 66 with the 6% cross-linking agent (triallyl isocyanurate). Individual radiation doses caused structural and micro-mechanical changes which have a significant effect on the final properties of the polyamide 66 tested. The highest values of micro-mechanical properties were reached at radiation dose of 30 kGy, when the micro-hardness values increased by about 64%. The aim of the article is to find out the influence of the radiation on the micro-hardness of the modified glass fiber-filled Polyamide 66 (PA66).

Abstract: In this work, were obtained nanocomposite membranes polyamide66/Paraíba bentonite clay, treated with a quaternary ammonium salt in order to make it organophilic. The membranes were prepared as thin films using the technique of phase inversion from the nanocomposites obtained by solution. The membranes were characterized by X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetry (TG) and scanning electron microscopy (SEM). By means of X-ray diffractogram, it was revealed that the membranes remained organically treated clay presented exfoliated and/or partially exfoliated structure. From curves of DSC and TG, it was observed that membrane of PA66 with 3% w/w of with treatment clay showed higher thermal stability compared with the same content of clay without treatment. From the SEM photomicrographs, there was a selective layer (skin filter) on top and one porous layer at the bottom of all membranes studied. Moreover, it was verified that the presence of clay provided a significant structural modification in the membranes of polymer nanocomposites.

Abstract: The bentonite clay fillers are mostly used for the development of nanocomposites, due to having characteristics which provide to obtain in nanometric particles. The bentonite clay was treated with an ammonium quaternary salt to modify it to organophilic clay. The polymeric membranes and nanocomposites were prepared using the phase inversion technique. The bentonite and organophilic clays were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The membranes were characterized by XRD. The results of XRF, XRD and FTIR confirmed the presence of quaternary ammonium salt in the organoclay structure. The XRD diffraction patterns of nanocomposites membrane showed exfoliated and/or partially exfoliated structure. According to the obtained results, it could be seen that the treatment performed on the surface of the clay was quite promising and efficient to be added as nanofillers on polymeric membranes.

Abstract: Membranes can be defined as polymer film that acts as a semipermeable barrier to filtration in a molecular scale, separating two phases. In this work, microporous membranes were obtained from hybrid organic/inorganic polyamide66 (PA66) and clay mineral from Paraíba State, treated with a quaternary ammonium salt in order to make it organophilic. The membranes in the form of thin films were prepared by immersion-precipitation technique from the nanocomposites obtained by solution, with a pre-determined reaction time of 2 h, with characteristics suitable to be used in microfiltration process for separation of the oil present in water. Samples of natural and organophilic clay were characterized by X-ray fluorescence (XRF) and Fourier transform infrared spectroscopy (FTIR). Meanwhile, the membranes were characterized by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The results of FRX and FTIR confirmed the presence of quaternary ammonium salt in the clay structure after treatment with organic salt. Through DSC analysis it was observed almost no change in the melting temperature of the pure polyamide66 membranes. By SEM, it was revealed an asymmetric morphology consisting of a skin layer and a porous sublayer, showing the pore size distribution appropriated to water-oil separation.

Abstract: The development of nanocomposites polymer matrix with clay from Brazil has been naturally abundant and low cost alternative. In this study, we obtained nanocomposites polyamide66 (PA66) with 1% and 5% of bentonite clay from Brazil, to be used as microporous organic/inorganic hybrid membranes. The clay was treated with a quaternary ammonium salt in order to make it organophilic. The membranes in the form of thin films were prepared using the technique of immersion-precipitation of solution from the nanocomposites. Treated clay and untreated clay were characterized by X-ray diffraction (XRD) and Thermogravimetry (TG). The membranes were characterized by TG and XRD. The result of XRD showed the presence of quaternary ammonium salt in the structure of clay, after organophilization. For TG, we observed that the treated clay showed higher thermal stability when compared to untreated clay. For TG, we observed that in general the membranes of PA66 with treated clay, present decomposition temperature higher when compared with untreated clay, thus revealing a greater thermal stability of membranes PA66 with treated clay. Through the X-rays patterns, it was found that membranes with 1% of nanoclay present exfoliated structure and can therefore be applied as microporous membranes.

Abstract: Bentonites are the most used fillers in the development of nanocomposites, due to their characteristics that provide nanosized particles, contributing to a large contact area between the clay and the polymer. In general, the additions of small amounts of organoclay improve the mechanical and thermal properties of nanocomposites. Bentonite clays and organoclays were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetry (TG). The results of XRF, XRD and FTIR confirmed the presence of quaternary ammonium salt in the organoclay structure. From TG, it was observed that the organoclay showed better thermal stability when compared with bentonite clay.