Silica Resin Reinforcement

Suwanprateeb and Hatthapanit [6] compared the use of black rice husk ash based silica as a filler in epoxy resins used for embedding electrical and electronic devices to the use of two commercial fillers, fused silica and crystalline silica, at different weight fractions between 20-60%. Increased mixing viscosity, thermal expansion 

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High density charring ablators such as carbon-phenolic contain high density reinforcements to improve shear resistance. In contrast, lower density charring ablators as a rule are used for low shear environments. Hie Apollo mission reentry conditions are typical of a relatively low shear environment, so low density ablators consisting of epoxy—novolac resin containing phenolic microballoons and silica fiber reinforcement have been used. In order to improve the shear resistance and safety factor of the material for this mission, the ablator was injected into the cavities of a fiberglass -reinforced phenolic honeycomb that was bonded to the substructure of the craft (48). 

Dynamic mechanical thermal analysis of several of the norbornene functional organic resins and the silicone resins gave relatively unremarkable results. The maximum for tan 5 peaks were in good agreement with Tg detamiined by DSC. The silicone elastomer (with 35% fumed silica as reinforcing filler) exhibited a Tg of ca. -90°C and a Tm at ca. -30 C which is typical for this type of polymer. 

Ros Rosso, P., Ye, L., Friedrich, K., Sprenger, S. A toughened epoxy resin by silica nanoparticle reinforcement. J. Appl. Polym. Sci. 100 (2006) 1849-1855. 

Sreekala M S and Eger C (2005) Property improvements of an epoxy resin by nano-silica particle reinforcement, in Polymer Composites from Nano- to Macroscale (Eds. Friedrich K, Fakirov S and Zhang Z) Springer, Berlin, Ch. 6, pp. 91-105. 

Epoxy, polyester, phenolic and other resins are used as coatings and linings with or without reinforcement. Glass fiber, silica, carbon and many other materials can be used as filters or reinforcement to produce materials with specific properties of strength, flexibility, wear resistance and electrical conductivity. 

Phenolic resin with an organic (nylon), inorganic (silica), or refractory (carbon) reinforcement Precharred epoxy impregnated with a noncharring resin... 

Compounding ingredients which bring about reinforcement of rubbers. The most widely used are carbon black, silica and silicates, zinc oxide, treated whitings, high styrene resins and phenolic resins. 

The hand lay-up or spray-up process, used universally for the production of laminar composites incorporating glass fiber reinforcement, is most efficient for the manufacture of large parts, such as boats, bathtubs, tanks, architectural shapes, and recreational accessories. Resins intended for spray-up processes are usually modified with thixotropic additives, such as fumed silica (1%), to reduce the risk of drainage when applied over large vertical mold surfaces. Molds are also made from FRP for short-run products usually surfaced with a tooling gel coat to provide consistent surface quality and appearance. 

Organic matrices are divided into thermosets and thermoplastics. The main thermoset matrices are polyesters, epoxies, phenolics, and polyimides, polyesters being the most widely used in commercial applications (3,4). Epoxy and polyimide resins are applied in advanced composites for structural aerospace applications (1,5). Thermoplastics Uke polyolefins, nylons, and polyesters are reinforced with short fibers (3). They are known as traditional polymeric matrices. Advanced thermoplastic polymeric matrices like poly(ether ketones) and polysulfones have a higher service temperature than the traditional ones (1,6). They have service properties similar to those of thermoset matrices and are reinforced with continuous fibers. Of course, composites reinforced with discontinuous fibers have weaker mechanical properties than those with continuous fibers. Elastomers are generally reinforced by the addition of carbon black or silica. Although they are reinforced polymers, traditionally they are studied separately due to their singular properties (see Chap. 3). 

Cementitious composites including FRP powder that was mainly composed of unsaturated-polyester resin, CaC03 (filler of FRP) and GF (reinforcement of FRP) were investigated. The grain size of FRP powder is similar to A3 silica sand. These suggest FRP powder to use as a substitute of A3 silica sand to extrudable composite. 

Minerals were used in the range of 30 to 60 percent by weight. The most useful minerals were ground quartz (SIO2), Wollastonlte (CaSiOs) and calcined clay. Although the silica is very abrasive and could not be tolerated in an injection molding or extrusion resin, the slurries in the low viscosity caprolactam were pumped and cast without excessive abrasion. Calcined clay is much less abrasive than silica and is preferred if the mineral reinforced polymer Is to be post-processed by injection molding. 

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