Papers by Keyword: Talc

Abstract: This paper reports the synthesis, characterizations, microstructure and properties of forsterite powder produced in Thailand from talc and magnesite as raw materials by using mechanical activation with subsequent calcination. The synthesis forsterite powder were mixed by using talc and magnesite at 1:5 mole ratio. The maximum milling time was 24 h in a planetary zirconia ball mill. Afterward, the mixtures were calcined in an electric furnace for 1 h at 900, 1000, 1100, 1200 and 1300°C respectively. The synthesized powder was characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM) and physical properties. Results of the physical properties of synthesized forsterite showed an increased in density as the calcining temperature increased. In contrast, porosity was decreased with an increase of the calcining temperature. Therefore, forsterite that was calcined at 1300°C provided the best results which were 2.96 g/cm³ of true density and 15.41% of true porosity. Results of XRD of synthesized powder indicated that the forsterite crystallization was constant for which sharpen appeared after 5 h of mechanical activation. Fraction of forsterite was appeared after being calcined at 1000°C for 1 h with an increasing of calcination temperature, the fraction of forsterite phase increased. Based on the mentioned characteristics, the forsterite produced from Thai talc and magnesite exhibited properties of an insulator and can potentially be used as refractory devices.

Abstract: The influence of talc and various polymeric additives on the basic mechanical properties of polyphenylenesulfone was investigated. It was found out that with the increase in the filler concentration there is an increase in stiffness, tensile strength and a decrease in the plasticity of the polyphenylenesulfone. While studying of polymer-polymer composites based on polyphenylenesulfone, high efficiency of polycarbonate as a modifier of impact strength was revealed. An effective method for producing a composite with a high impact strength and a modulus of elasticity has beendeveloped; it is based on the features of the distribution of the filler in the binary system polyphenylenesulfone – polycarbonate. The concentration of the filler in the polycarbonate phaseleads to low values of impactstrength, while its concentration in the phase of polyphenylenesulfone, followed by the introduction of polycarbonate leads to the formation of a high impact and high modulus composite. The samples obtained by 3D printing have high mechanical characteristics.

Abstract: The results of the studies of the effect of excipients of mineral and organic origin on the mechanical properties of polyether sulfone based on 4,4'-dihydroxydiphenyl and 4,4'-dichlordiphenylsulfone are adduced. It has been shown that the introduction of hard fillers is accompanied by the increased modulus and reduced ductility of the polymer matrix, the intensity of these effects depends on the concentration, shape and particle size additives. It was revealed that the composites with talc and discrete carbon fibers were characterized by higher mechanical properties. Their test as materials for FDM 3D printing method shows the highest suitability composites with talc for this technology.

Abstract: Molybdenite and talc were selected as research object in paper and crystal structure, interaction between H₂O molecule and minerals surfaces, surface wettability, flotation behavior were studied by density functional theory method and flotation experiments. The results showed that molybdenite and talc were layered minerals which exhibited similar surface wettability. H₂O molecule had hardly effect with molybdenite or talc and H₂O molecule prefers to stay with water rather than the minerals surfaces. The reason why talc interferes with the flotation molybdenite has been revealed. The flotation results showed that good floatability of talc was the key factor causing a low grade of concentrate in alkaline solution. Thus, it is the key factor to enlarge floatability difference between molybdenite and talc.

Abstract: In this paper, effects of incorporation of Narathiwat clay (NT), talc and silica on the mechanical properties of cordierite-mullite refractories were investigated. The starting raw materials were mixed in different ratios and fired at 1300 °C for 2 hours. XRD patterns of fired refectories indicated cordierite and mullite phases. The fired samples were studied the firing shrinkage, water absorption, bulk density, apparent porosity and bending strength of the cordierite-mullite refractories. The optimum condition was achieved for the composition of 20% Talc that had shrinkage: 11.78%, water absorption: 4.16%, bulk density: 2.28 g/cm³, apparent porosity: 9.2% and bending strength: 330.82 kg/cm². The results thus showed that Narathiwat clay, talc and silica was a potential materials for use kiln furniture cordierite-mullite refractories.

Abstract: Polypropylene (PP), a versatile polymer finds application in many sectors. However, it has low impact strength.To overcome this draw back elastomer is added, which results in improved impact property at the expense of decreased tensile strength. To improve this fillers are added. However some fillers also improve impact strength. In this work only fillers have been used to get balance of properties in PP. Knowledge of crystallization of PP is important for processing of PP. In this work the effect of hybrid fillers on PP has been studied on the isothermal and non-isothermal crystallization kinetics of PP. The fillers used are coir and talc.

Abstract: The development of renewable resource based and inherently biodegradable polymers as well as their composites are one of the most important research fields nowadays in polymer science. Poly (Lactic Acid) (PLA), as the most promising biodegradable polymer has the potential to replace even engineering composite materials by reinforcing it with natural plant fibres or mineral fibres like basalt. However, one major drawback is its low heat deflection temperature (HDT, ~55°C) caused by its slow crystallization kinetics and thus low crystallinity of the final product. This feature also retards the usage of PLA in composite materials for elevated temperature applications. At the same time, nucleating agents like talc can be used to enhance crystallinity and thus HDT. In this paper basalt fibre reinforced and talc filled PLA composites were prepared by extrusion followed by injection moulding. The results showed that by combining the stiffness increasing effect of basalt fibres as well as the crystallinity increasing effect of talc, a composite with both high mechanical properties and high HDT could be produced.

Abstract: The slow crystallization speed of poly(Lactic acid)(PLA) has limited its application. In this work, the surface of Talc was grafted with oligo PLA, and then modifed Talc /PLA was prepared, and the results showed that the modified HA could greatly enhanced the crystallization of PLA.

Abstract: The mechanical and heat properties of fully biodegradable elastomer PHA and PLA composites were studied. The effects of types and contents of coupling agents, mesh and contents of Talc on mechanical properties, MFR of PHA/PLA composites were studied. We found that when PHA: PLA=70:30, the PHA/PLA composites are stiff, flexible and good heat resistant. With 1% ligand titanic acid ester coupling agent treat 20 parts of 3000 mesh Talc, we can get the best PHA/PLA/Talc ternary composites. The DSC results indicate that the PHA/PLA/Talc ternary composite has the rapid crystallization temperature between 50-75°C, the melt temperature is about 150°C.

Abstract: Carbon nanotubes-talc (CNTs-talc) hybrid compound has been successfully synthesized via chemical vapour deposition (CVD) method. A gas mixture of methane/nitrogen (CH₄/N₂) was used as the carbon source and nickel as the metal catalyst for the growth of CNT hybrid compound. Talc works as substrate or support material which is combined with nickel to form a complex metal-talc catalyst that will react with carbon source to produce the hybrid compound. To study the effect of different calcinations temperature, four different calcinations temperature, 300 °C (C-talc300), 500 °C (C-talc500), 700 °C (C-talc700) and 900 °C (C-talc900) were used. Among these four calcination temperatures for synthesis the multi-walled carbon nanotubes (MWCNTs), C-talc500 is the most optimum calcination temperature to perform catalytic decomposition by reacting in methane atmosphere at 800 °C to produce the CNT-talc hybrid compound.