Inorganic fibrous reinforcements

No single fibrous reinforcement embodies all the desirable characteristics of asbestos flbers. Combinations of organic and inorganic flbers are used in friction materials to achieve the desired effect. Given the past experience with asbestos, end-users of fibrous reinforcements have to insure that the materials do not cause cancer, fibrotic lung disease, or pulmonary dysfunction. 

Nowadays, in place of asbestos, fibrous reinforcements are used that include glass fiber, steel fiber, aramid fiber, potassium titanate fiber, etc. Since these fibrous reinforcements have their own specific properties, in practice, a mixture of them is used. Potassium titanate fiber is a hard inorganic fiber. It can improve the strength, the heat resistance and the wear resistance of the fiietion material. In addition, it can enhance the friction coefficient of the friction material through its abrasive property. 

Ceramic fiber reinforcements n. Non-metallic inorganic fibrous materials, available in a wide spectrum of forms, both continuous and discontinuous. 

A natural inorganic fibrous material, mainly composed of chrysolite, that was used as an effective reinforcing material in the past. Asbestos is a proven lung cancer producing agent and... 

Asbestos fibers are found worldwide in many products as reinforcement in cement water pipes and the inert and durable mesh material used in filtration processes of chemicals and petroleum, for example. However, asbestos is not the only inorganic fiber in use today. Synthetic inorganic fibers abound. Glass fibers have replaced copper wire in some intercontinental telephone cables. Fiberglas (a trade name) has become the insulation material of choice in construction. Carbon and graphite fiber composites are favored materials for tennis racket frames and golf clubs. Fibrous inorganic materials have become commonplace in our everyday lives. 

Basically a plastic composite is the assembly of two or more materials made to behave as a single product. Examples include vinyl-coated fabric used in air mattresses or laminated metal bonded together with a plastic adhesive used in helicopter blades. The RP type of composite combines a plastic with a reinforcing agent that can be fibrous, powdered, spherical, crystalline, or whisker, made of organic, inorganic, metallic, or ceramic material. To be structurally effective, there must be a strong adhesive bond between the resin and reinforcement. 

The formation of composites by reinforcing polymers with particulate or fibrous polymeric or inorganic materials has been accepted as a general means in improving the wear resistance of polymers. One of the interesting developments is reinforced thermoplastics, such as carbon fiber-PEEK. The uses of LCPs, e.g., Kevlar, PBT, as reinforcing media for amorphous matrices are also of significant interest. 

Other fibrous inorganic reinforcements, e.g., Refrasil quartz or asbestos should be equally suitable for use in space but data lacking to support recommending them. These reinforcements are generally used for more specialized applications such as thermal insulation, ablation, etc., where mechanical strength properties are secondary to heat resistance. 

Fibrous fillers for biomedical PLA-based FRPs include carbon and inorganic fibres [406], PLLA (i.e. self-reinforcement) [407,408], poly(p-dioxane) fibre [409], chitin [410], biodegradable fibre (e.g. bioactive glass, chitosan fibre, polyester amides) [411], hydroxyapatite fibre [412], hydroxyapatite whiskers [413], halloysite (Al2Si205(0H)4) nanotubes [414] and the fibre from different tissue types of Picea sitchensis [415],... 

The composites can be classified on the basis of the form of their structural components fibrous (composed of fibers in a matrix), laminar (composed of layers of materials), and particulate (composed of particles in a matrix). The particulate class can be further subdivided into flake (flat flakes in a matrix) or skeletal (composed of a continuous skeletal matrix filled by a second material). In general, the reinforcing agent can be either fibrous, powdered, spherical, crystalline, or whiskered and either an organic, inorganic, metallic, or ceramic material. 

It has been well recognized that melt blending of a thermotropic liquid crystalline polymer (LCP) and an isotropic polymer produces a composite in which fibrous LCP domains dispersed within the blend act as a reinforcement il ). The so-called insitu composite possesses several advantages in comparison with the inorganic reinforced thermoplastic composites. Firstly, LCP lowers the blend viscosity in the actual fabrication temperature range (3-5), Hence, the enhanced processability endows moldability for fine and complex shaped products. 

Inorganic whiskers, a kind of single crystal fibrous or needle-like material that appeared in recent years, are used to reinforce thermosetting resin, thermoplastic resin, rubber, metal, and ceramics through filling and to prepare advanced engineering plastic, composite materials, adhesive, sealant, and paint. The excellent performances of inorganic whiskers have led to their wide application as composite materials- ... 

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