Acrylic fiber reinforcements

Acrylics processed by compression-molding techniques give dentures as satisfactory and dimensionally stable as the estimated 5% of the dentures made with special resins and elaborate processing equipment (208). Promising fiber-reinforced dentures have been reported (209—212). 

Crazing. This develops in such amorphous plastics as acrylics, PVCs, PS, and PCs as creep deformation enters the rupture phase. Crazes start sooner under high stress levels. Crazing occurs in crystalline plastics, but in those its onset is not readily visible. It also occurs in most fiber-reinforced plastics, at the time-dependent knee in the stress-strain curve. 

Sanitary ware, including tubs, showers, combined units, basins, and toilet tank, may be made of thermoformed ABS or acrylic sheet, molded glass-fiber-reinforced polyester, or cast acrylic resins. The glass-polyester type dominates the tub/shower market. It is possible to install the units as a two-component system, assembled in place. Gel coats may be of thermoformed decorative acrylic skins. To reduce the smoke generated by fire, methyl... 

See also Acrylic Plastics Elastomers Fiber-Reinforced Compos ites Polyester Fibers and Polymers. 

Poly(pentabromobenzyl acrylate), another polymeric fire retardant, is particularly suitable for use with polyamides whether or not they contain fiber reinforcement. Its advantages over other fire-retardant additives result from a combination of its polymeric nature, high bromine content, and thermal stability. 

Acrylic window pane fiber-reinforced lorylic sun shield Vinyl gaskets... 

AFK asbestos fiber reinforced plastic ANM acrylate rubber... 

Carbon fiber is made from acrylic fiber by pyrolysis. Around 1960, Dr. Shindo of "the Governmental Industrial Research Institute, Osaka" found that polyacrylonitrile fiber was carbonized under suitable conditions and yielded carbon fiber with high-strength and high-modulus. At that time, advanced composite materials reinforced with such carbon fibers were unclear, but In 1965, Toray came to be involved in the development of carbon fiber. 

The low hot-wet strength of acrylics can be attributed to the maimer in which water plasticizes the unique laterally bonded acrylic fiber structure. The water lowers the Tg to approximately 70°C, but this is not sufficient to account for the extremely low modulus near the boil, since other fibers including nylon are also highly plasticized by water. However, these fibers contain a well-defined, stable, three-dimensional crystalline phase that is thought not to be penetrated by the water. Therefore, they can act to reinforce the fiber and limit the drop in modulus at temperatures above the Tg, where the amorphous phase has become rubbery. The crystalline phase in the acrylic fiber is highly imperfect (as was discussed in Section 12.4) and can probably be easily penetrated and plasticized by the water. 

Metalized and semiconducting fibers have also been discussed [585-587]. Another key industrial application for acrylic fibers is for asbestos replacement, especially for concrete reinforcement and friction surfaces. An example of a concrete and mortar reinforcement fiber is Dolanit acrylic from Faserwerk Kelheim GmbH [588]. The subject has been reviewed by a number of authors [589-591]. Other acrylic fiber modifications and reviews of acrylic fiber modifications, in general, have been published by several authors [592-596]. A comprehensive summary of specialized acrylic and modacrylic fibers is given in Table 12.35. The major types. 

Acrylic fibers, such as Dolanit, are blended in ambient-cured cement at a rate of 1-3%, compared with 9-15% by weight of asbestos. The flexural strength of cement sheets of acrylic-reinforced cement is equivalent to that of asbestos-reinforced cement and nearly double that of untreated cement, as shown in Table 12.39 [655]. 

Cellulose nanofibers from different sources have showed remarkable characteristics as reinforcement material for optically transparent composites [160, 161], Iwamoto et al. [160] prepared optically transparent composites of transparent acrylic resin reinforced with cellulose nanofibers extracted from wood pulp fibers by fibrillation process. They showed that cellulose nanofiber-reinforced composites are able to retain the transparency of the matrix resin even at high fiber content (up to70 % wt). The aggregation of cellulose nanofibers also contributes to a significant improvement in the thermal expansion properties of plastics. 

Uses Reactive epoxy diluent for exposed aggregates, potting, flooring, casting, tooling, laminates, solv.-free coating systems, fiber-reinforced composites stabilizer for chlorinated hydrocarbons adhesion promoter for PVC, acrylic resins, PU Manuf./Distrib. Aldrich Raschig... 

Uses Crosslinking agent in casting compds., glass fiber-reinforced plastics, adhesives, coatings, ion-exchange resins, textile prods., plasti-sols, dental polymers, rubber compding. reactive diluent for radiation-cured inks, lacquers crosslinked acrylic resin comonomer Trade Names SR 239... 

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