Mechanical properties talc reinforcement

Carbon fiber-reinforced PAs may be used for conductive and electrical shielding applications where high mechanical properties are also required, and for applications requiring a measure of internal lubrication, slip and good wear-resistance. Mineral-reinforced PA (with talc or mica) offers very good dimensional stability, and low shrinkage and warpage. 

Filler particles such as talc or carbon black are routinely incorporated in rubber compounds to improve mechanical properties. Guth [51] related this reinforcement effect to the Einstein viscosity law for colloidal emulsions... 

Reinforcements are used to enhance the mechanical properties of a plastic or elastomer. Finely divided silica, carbon black, talc, mica, and calcium carbonate, as well as short fibers of a variety of materials, can be incorporated as particulate fillers. Incorporating large amounts of particulate filler during the making of plastics such as polypropylene and polyethylene can increase their stiffness. The effect is less dramatic when temperature is below the polymer s Tg. 

Polypropylene is a very versatile polymer. It has many properties that make it the polymer of choice for various applications (e.g., excellent chemical resistance, good mechanical properties and low cost). There are many ways in which the mechanical properties of polypropylene can be modified to suit a wide variety of end-use applications. Various fillers and reinforcements, such as glass fiber, mica, talc, and calcium carbonate, are typical ingredients that are added to polypropylene resin to attain cost-effective composite mechanical properties. Fibrous materials tend to increase both mechanical and thermal properties, such as tensile strength, flexural strength, flexural modulus, heat deflection temperature, creep resistance, and sometimes impact strength. Fillers, such as talc and calcium carbonate, are often used as extenders to produce a less-costly material. However, some improvement in stiffness and impact can be obtained with these materials. 

A wide range of other reinforcing agents have been used to improve the mechanical properties of polymers. These include clays, calcium carbonate, silica, talc, alumina (see Table 2.6). 

Keywords filler, aspect ratio, particle shape, calcium carbonate, talc, platelets, reinforcement, glass fiber, kaolin, particle size, particle size distribution, chemical composition, adhesion, interface, aggregation, specific surface area, flow-induced orientation, hardness, surface free energy, surface tension, surface treatment, mechanical properties, thermal properties. 

The mechanical properties of polymers can be considerably improved by the incorporation in their formulation of reinforcing agents or fillers. These have been used to improve or alter the mechanical properties of polymers. These include glass fiber, glass beads, calcium carbonate, minerals, mica, talc, clay, carbon fiber, carbon nanotubes, aluminum or other metal powders, silica and silicones, and others [1-16]. 

Chemical coupling agent for glass, aica, and talc reinforced polypropylene giving enhanced physical and thermal properties Coapatabilizer for blends such as polyprc ylene/polyaaide and polypropylene/EVOH to improve processability and mechanical prc>perties. 

Polymer nanocomposites consist of a polymer matrix with embedded filler particles with at least one dimension at the nanometre level, (i.e. 1-100 nm), much smaller than for the conventional polymer composites described above. The inclusion of nanoparticles can effect significant improvements in mechanical properties such as modulus, yield stress and fracture toughness for filler levels as low as a few per cent by weight. This is much lower than in conventional polymer composites, as illustrated in Figure 9.7, where the effect of talc reinforcement and clay nanoparticle reinforcement in a polypropylene matrix are compared. Talc filler is regarded as a conventional reinforcement, with particle diameters in the range 1-10 qm and thickness around 20 times less, whereas the clay particles are of length around 100 nm and thickness as low as 1 nm. Clay occurs in the form of platelets and has been... 

Figure 9.7 Comparison of talc reinforcement with nanoclay (montmorillonite) reinforcement, in terms of the ratio of composite modulus to matrix modulus. The matrix material is a blend of polypropylene and thermoplastic elastomer (TPO). (Reproduced from Lee H-s. et al. (2005) TPO based nanocomposites. Part 1. Morphology and mechanical properties Polymer, 46, 11673-11689. Copyright (2005) Elsevier Ltd.)...

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