Silica reinforcement polypropylene

Polypropylene Glass reinforced Silicones Molded, Laminated Granular (silica) reinforced silicones ABS-Polycarbonate Alloy Polymides Unreinforced 0.002 0.002—0.004 0.0026 0.003... 

This technology was first commercially applied to polyurethane blend [121] and patented as Rimplast (for Reactive Injection Molding), but many polymers have since been blended with polysiloxane thanks to this method polyethylene [122], polypropylene [122,123], polyamide [124-130], polyesters [128,131-133], poly(phenylene ether) [134], fluorocarbons [135] and many more. Many of them include reinforcing fillers such as fumed silica. The silicone base involved can moreover contain reactive groups such as the epoxy group [136,137]. A typical silicone base useful for these blends was de-... 

Polymeric fibers are popular for reinforcing concrete matrices because of their low density (more number of fibers for a prescribed volume fraction), high tensile strength, ease of dispersion, relative resistance to chemicals, and relatively low cost compared to other kinds of fibers. Polypropylene and polyolefin fibers are typically hydrophobic, resulting in a relatively poor bond with concrete matrices compared to some other types of fibers. Treatment of polypropylene with an aqueous dispersion of colloidal alumina or silica and chlorinated polypropylene enhances the affinity of these fibers toward cement particles. Treatment of polypropylene fibers with a surface-active agent provides better dispersion of the fibers and a stronger bond between cement and fiber. The earlier attempts at surface treatments of polypropylene fibers have had only limited success and have not been commercially attractive. 

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. 

Siriwardena S, Ismail H, Ishiaku US (2003) A comparison of the mechanical properties and water adsorption behavior of white rice husk and silica filled polypropylene composites. J Reinforc Plast Compos 22 1645-1666... 

A new area of development is to incorporate the filler permanently into the polymer matrix, by use of coupling reactions. This can increase impact strength and thermal properties of polyamides and modify the anisotropy of partially crystalline plastics, such as polyamides and polyesters. In polypropylene, bonding with kaolin can also improve scratch resistance, which is a useful benefit for automobile interior applications. Surface modification of fillers such as silica, mica, and wollastonite allows these to penetrate markets that were formerly the province of reinforcements such as carbon black and glass fibre. 

They found that both grades of RHA, low- and high-carbon contents, provided inferior mechanical properties (tensile strength, modulus, hardness, abrasion resistance, and tear strength) compared with those of reinforcing filler such as silica and carbon black. Other finding reported that incorporation of RHA into polypropylene led to an increased flexural modulus of the composites (Fuad et al. 1998). 

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