Tensile strength fibrous composites

As shown in Table 13.2, the heat deflection temperature of ABS is increased by the incorporation of fibrous glass. The copolymer reinforced with 20% fibrous glass has a lower coefficient of linear expansion (2.0 X 10 5 on/cm C) and higher compressive, flexural, and tensile strengths than unfilled SAN. These improvements are related to the amount of fibrous glass present in the composite. 

Asbestos constitutes several types of hydrated silicate mineral fibers. The types of asbestos, their chemical compositions, and CAS Numbers are presented in Table 3.8.1. These substances occur in nature in rocks, silicate minerals, fibrous stones, and underground mines. This class of substances exhibits unique properties of noncombustibility, high resistance to acids, and high tensile strength for which they were widely used in many products, including floor and roofing tiles, cement, textiles, ropes, wallboards, and papers. Because of the health hazards associated with excessive exposure to asbestos, the use of these substances is currently banned. 

Figure 10. Scanning electron micrograph of a composite of cellulose powder-lignin powder mixture. The hig, fibrous cellulose particle (right) appears to be bonded to the big amorphous lignin particle (left). A split in the cellulose particle suggests that bonding between lignin and cellulose particles was stronger than the tensile strength of cdlulose perpendicular to the fiber axis (12A).

Due to their fibrous stracture and remarkable properties, carbon nanotubes are suitable to the production of polymer composites. Their extreme tensile strength... 

Fillers may be divided into particulate and fibrous types. Particulates include calcium carbonate, china clay, talc and barium sulphate. Fillers affect shrinkage on moulding and the dimensional stability of the finished plastic, increase tensile strength and hardness, enhance electrical insulation properties and reduce tackiness. They also impart opacity and colour (Figure 3.16). Carbon black is now the most widely used filler for polymers usually in the form of furnace carbon black, which has a particle diameter of 0.08 mm. Fibrous fillers reinforce polymers and greatly increase their tensile strengths. They include fibres of glass, textile and carbon. Plastics filled with fibrous fillers are known as composites. 

The ultimate tensile strength of a fibrous composite a depends on whether failure is fiber-dominated or matrix-dominated. The latter is common when Vt is small. One result of such treatment is... 

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. 

Wood, being a fibrous polymer composite itself, and an abundant renewable raw material, offers its cellulosic fiber as a reinforcement for S3mthetic polymers. Indeed, the tensile strength of the cellulosic fiber is similar to that of an E-glass fiber (up to 1 GPa), and its modulus is also high enough (up to 70 GPa) [1]. 

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